Agronomy

16 pages, 1684 KiB

Open AccessEditor’s ChoiceArticle

Origanum dictamnus Essential Oil in Vapour or Aqueous Solution Application for Pepper Fruit Preservation against Botrytis cinerea

by Nikolaos Tzortzakis

Agronomy 2024, 14(2), 257; https://doi.org/10.3390/agronomy14020257 - 25 Jan 2024

Cited by 4 | Viewed by 1923

Abstract

The use of synthetic sanitizers for fresh commodities preservation is of concern, with eco-friendly alternatives, including essential oils (EOs), attracting research and industry interest. Dittany (Origanum dictamnus—DIT) oil was applied, either through vapour or dipping, on pepper fruit or in vitro [...] Read more.

The use of synthetic sanitizers for fresh commodities preservation is of concern, with eco-friendly alternatives, including essential oils (EOs), attracting research and industry interest. Dittany (Origanum dictamnus—DIT) oil was applied, either through vapour or dipping, on pepper fruit or in vitro against Botrytis cinerea, and compared to untreated (control) or chlorine (CHL)-treated fruits stored at 11 °C. Direct DIT vapours (up to 6 d) suppressed lesion growth, spore germination, and spore production compared to the untreated fruits. The antimicrobial properties of EOs were evidenced in pre-exposed-to-DIT oil vapours (residual effect), resulting in fruit lesion suppression. However, DIT-pretreated fruits had the same spore production and spore germination as the control and CHL applications. In in vitro tests, DIT vapours decreased colony growth and spore production when fungi were grown on Potato Dextrose Agar (PDA) or PDA pre-exposed to DIT following B. cinerea inoculation. This evidenced that the disease suppression after DIT vapour application primarily affected the interaction of the fruit–pathogen and/or residual responses on fruit tissue and/or PDA media. Fungal biomass in Potato Dextrose Broth (PDB) was evaluated after DIT and CHL applications (10–50–100–500–5000 μL L⁻¹) and decreased with the DIT oil. Additionally, DIT or CHL sanitary dipping on pepper was ineffective against B. cinerea compared to vapour application. Therefore, DIT vapours revealed antimicrobial properties and could be an alternative postharvest sanitiser. DIT oil application should also be evaluated at semi-commercial scale for further optimizations, prior to commercialisation. Full article

(This article belongs to the Special Issue It Runs in the Family: The Importance of the Lamiaceae Family Species)

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10 pages, 819 KiB

Open AccessEditor’s ChoiceArticle

Tillage with Crop Residue Returning Management Increases Soil Microbial Biomass Turnover in the Double-Cropping Rice Fields of Southern China

by Haiming Tang, Chao Li, Lihong Shi, Li Wen, Weiyan Li, Kaikai Cheng and Xiaoping Xiao

Agronomy 2024, 14(2), 265; https://doi.org/10.3390/agronomy14020265 - 25 Jan 2024

Cited by 5 | Viewed by 1266

Abstract

The variety of soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN) content, and the flux turnover rate of SMBC and SMBN for 0–10 cm and 10–20 cm layers in a paddy field in southern China with different tillage practices were studied. [...] Read more.

The variety of soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN) content, and the flux turnover rate of SMBC and SMBN for 0–10 cm and 10–20 cm layers in a paddy field in southern China with different tillage practices were studied. The tillage experiment included conventional tillage and crop residue returning (CT), rotary tillage and crop residue returning (RT), no–tillage and crop residue returning (NT), and rotary tillage with all crop residues removed from the paddy field as a control (RTO). The result showed that the SMBC and SMBN contents at 0–10 cm and 10–20 cm layers in the paddy field with CT, RT, and NT treatments were significantly increased. This result indicates that the flux turnover rate of SMBC and SMBN for 0–10 cm and 10–20 cm layers in the paddy field with CT treatment were increased by 65.49%, 39.61%, and 114.91%, 119.35%, compared with the RTO treatment, respectively. SMBC and SMBN contents and the flux turnover rate of SMBC and SMBN for the 0–10 cm layer were higher than that of the 10–20 cm layer in paddy fields under the same tillage condition. Therefore, applying rotary tillage or conventional tillage and crop residue returning produced beneficial management for increasing soil microbial biomass content and its turnover under a double–cropping rice system in southern China. Full article

(This article belongs to the Section Farming Sustainability)

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26 pages, 2602 KiB

Open AccessEditor’s ChoiceArticle

Fostering Agricultural Transformation through AI: An Open-Source AI Architecture Exploiting the MLOps Paradigm

by Antonio Carlos Cob-Parro, Yerhard Lalangui and Raquel Lazcano

Agronomy 2024, 14(2), 259; https://doi.org/10.3390/agronomy14020259 - 25 Jan 2024

Cited by 12 | Viewed by 6202

Abstract

As the global population is expected to reach 10 billion by 2050, the agricultural sector faces the challenge of achieving an increase of 60% in food production without using much more land. This paper explores the potential of Artificial Intelligence (AI) to bridge [...] Read more.

As the global population is expected to reach 10 billion by 2050, the agricultural sector faces the challenge of achieving an increase of 60% in food production without using much more land. This paper explores the potential of Artificial Intelligence (AI) to bridge this “land gap” and mitigate the environmental implications of agricultural land use. Typically, the problem with using AI in such agricultural sectors is the need for more specific infrastructure to enable developers to design AI and ML engineers to deploy these AIs. It is, therefore, essential to develop dedicated infrastructures to apply AI models that optimize resource extraction in the agricultural sector. This article presents an infrastructure for the execution and development of AI-based models using open-source technology, and this infrastructure has been optimized and tuned for agricultural environments. By embracing the MLOps culture, the automation of AI model development processes is promoted, ensuring efficient workflows, fostering collaboration among multidisciplinary teams, and promoting the rapid deployment of AI-driven solutions adaptable to changing field conditions. The proposed architecture integrates state-of-the-art tools to cover the entire AI model lifecycle, enabling efficient workflows for data scientists and ML engineers. Considering the nature of the agricultural field, it also supports diverse IoT protocols, ensuring communication between sensors and AI models and running multiple AI models simultaneously, optimizing hardware resource utilization. Surveys specifically designed and conducted for this paper with professionals related to AI show promising results. These findings demonstrate that the proposed architecture helps close the gap between data scientists and ML engineers, easing the collaboration between them and simplifying their work through the whole AI model lifecycle. Full article

(This article belongs to the Special Issue Data-Driven Agriculture: Remote Sensing and Machine Learning for Sustainable Farming Practices)

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20 pages, 3008 KiB

Open AccessEditor’s ChoiceArticle

Environmental Impact of Various Rice Cultivation Methods in Northeast China through Life Cycle Assessment

by Yu Wang, Wenqing He, Changrong Yan, Haihe Gao, Jixiao Cui and Qin Liu

Agronomy 2024, 14(2), 267; https://doi.org/10.3390/agronomy14020267 - 25 Jan 2024

Cited by 4 | Viewed by 2836

Abstract

Rice, a crucial staple in China, is cultivated through various techniques, including seedling transplanting, dry direct seeding, and film mulching. Despite its significance, rice production is a considerable environmental burden. Using a life cycle assessment (LCA) methodology, this study aimed to evaluate the [...] Read more.

Rice, a crucial staple in China, is cultivated through various techniques, including seedling transplanting, dry direct seeding, and film mulching. Despite its significance, rice production is a considerable environmental burden. Using a life cycle assessment (LCA) methodology, this study aimed to evaluate the environmental impacts of four rice cultivation methods (transplanting rice, dry direct-seeding rice, dry direct-seeding rice with polyethylene film (PE), and dry direct-seeding rice with biodegradable film) in Northeast China. The results indicate that the magnitude of environmental impacts among treatments was consistent across years. The potential values of all environmental impacts of the four different cultivation methods of rice in the 2021 field trial were smaller than the results of the same cultivation method of rice system in the 2022 field trial. Among the four rice cultivation methods, the consumption of energy showed inconsistency over the two years, with the highest energy consumption in the first year being for dry seeding with PE film and in the second year for dry seeding without film. Additionally, transplanting exhibited the highest impact on water resource consumption and climate change. Dry direct-seeding rice displayed the highest eutrophication and ecotoxicity. Dry direct-seeding rice with a biodegradable film had the least impact in terms of acidification. Moreover, dry direct-seeding rice with a biodegradable film minimized water consumption and greenhouse gas emissions without compromising yield. Full article

(This article belongs to the Special Issue The Impact of Mulching on Crop Production and Farmland Environment)

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17 pages, 2333 KiB

Open AccessEditor’s ChoiceArticle

Life Parameters and Physiological Reactions of Cotton Aphids Aphis gossypii (Hemiptera: Aphididae) to Sublethal Concentrations of Afidopyropen

by Wenjuan Ding, Longzhi Guo, Yannan Xue, Mei Wang, Chuanwang Li, Ruikai Zhang, Siwen Zhang and Xiaoming Xia

Agronomy 2024, 14(2), 258; https://doi.org/10.3390/agronomy14020258 - 25 Jan 2024

Cited by 6 | Viewed by 2028

Abstract

The massive and repetitive application of synthetic insecticides for the management of cotton pests results in the accumulation of resistance in Aphis gossypii Glover, a destructive pest worldwide. New chemistries are needed for pest management. Afidopyropen exhibits high efficacy against piercing-sucking pests and [...] Read more.

The massive and repetitive application of synthetic insecticides for the management of cotton pests results in the accumulation of resistance in Aphis gossypii Glover, a destructive pest worldwide. New chemistries are needed for pest management. Afidopyropen exhibits high efficacy against piercing-sucking pests and has been applied as a complementary alternative insecticide against aphids. This study was conducted to investigate the lethal and sublethal effects of afidopyropen on the life parameters and physiological responses of A. gossypii. Detoxifying enzyme activities and expression levels of P450 genes were compared after exposure to three generations of afidopyropen. Bioassay results indicate that afidopyropen possessed the highest toxicity, with a LC₅₀ value of 0.30 mg/L. Sublethal concentrations (LC₅ and LC₁₀) caused adverse impacts on the F0 generation, reducing adult longevity and fecundity. A high concentration (LC₁₀) also caused adverse effects on the F1 generation, while a low concentration (LC₅) stimulated the fecundity. After continuous treatments with afidopyropen, the susceptibility decreased. GSTs and P450 were induced through sublethal concentrations; moreover, their activities in the F3 generation were higher than that in the F0 generation. Furthermore, the expression levels of 12 P450 genes in the F3 generation were higher than those in F0 generation. In conclusion, afidopyropen has excellent acute toxicity and continuous control effects on A. gossypii. GSTs and P450 may play important roles in the resistance of A. gossypii to afidopyropen. Full article

(This article belongs to the Special Issue Adaptation and Responses of Insects under Abiotic, Biotic and Xenobiotic Constraints)

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18 pages, 10358 KiB

Open AccessEditor’s ChoiceArticle

Development and Optimization of a Rapid In Vitro Micropropagation System for the Perennial Vegetable Night Lily, Hemerocallis citrina Baroni

by Gaoya Zuo, Ke Li, Yining Guo, Xiaorun Niu, Lijin Yin, Zhiqiang Wu, Xiaomin Zhang, Xiaojing Cheng, Jie Yu, Shaowen Zheng, Yanfang Wang, Guoming Xing, Sen Li and Feifan Hou

Agronomy 2024, 14(2), 244; https://doi.org/10.3390/agronomy14020244 - 24 Jan 2024

Cited by 4 | Viewed by 2327

Abstract

The perennial herbaceous night lily, Hemerocallis citrina Baroni, is an important vegetable crop with an increasing production and consumption in China. The long lifecycle and slow growth of the night lily are becoming bottlenecks for the large-scale production of elite lines and various [...] Read more.

The perennial herbaceous night lily, Hemerocallis citrina Baroni, is an important vegetable crop with an increasing production and consumption in China. The long lifecycle and slow growth of the night lily are becoming bottlenecks for the large-scale production of elite lines and various genetic and breeding studies. There is a lack of a protocol for rapid and efficient micropropagation for this crop. Here, we reported the systematic investigation and optimization of in vitro plant regeneration through tissue-culture-based organogenesis in the night lily variety ‘Datong Huanghua’. We evaluated various factors affecting the efficiency of callus induction and subculture, shoot regeneration, rooting and plantlet establishment, including explant type and age, inoculation methods, basal culture media and the type and concentration of plant growth regulator (phytohormones) in various growth media. We developed an optimized protocol, as follows. The highest efficiency of callus induction was observed on Murashige and Skoog (MS) medium supplied with 22.7 µM TDZ (thidiazuron) using the young scape (flower stem or stalk) as the explant, which was cut longitudinally in half to produce a segment approximately 0.5 cm in length. Callus subculture and proliferation were more efficient on MS medium containing 9.0 µM 2,4-D (2,4-dichlorophenoxyacetic acid) under light culture conditions. Shoot regeneration showed the highest efficiency on MS medium supplemented with 8.9 µM 6-BA (6-benzylaminopurine) + 5.4 µM NAA (α-naphthaleneacetic acid), while the best rooting medium was MS medium containing 2.7 µM NAA. After transplanting, the transplanted regenerated seedlings showed the highest survival rate (96%) on a substrate mixture with a 2:1:1 ratio of peat/perlite/vermiculite. A protocol and flowchart for the rapid in vitro micropropagation of night lily plants is proposed that will facilitate various genetic, genomic and breeding studies on this crop. Full article

(This article belongs to the Collection Propagation and Conservation of Horticultural Plants: In Vitro and In Vivo)

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22 pages, 214283 KiB

Open AccessEditor’s ChoiceArticle

ESG-YOLO: A Method for Detecting Male Tassels and Assessing Density of Maize in the Field

by Wendi Wu, Jianhua Zhang, Guomin Zhou, Yuhang Zhang, Jian Wang and Lin Hu

Agronomy 2024, 14(2), 241; https://doi.org/10.3390/agronomy14020241 - 24 Jan 2024

Cited by 4 | Viewed by 2085

Abstract

The intelligent acquisition of phenotypic information on male tassels is critical for maize growth and yield assessment. In order to realize accurate detection and density assessment of maize male tassels in complex field environments, this study used a UAV to collect images of [...] Read more.

The intelligent acquisition of phenotypic information on male tassels is critical for maize growth and yield assessment. In order to realize accurate detection and density assessment of maize male tassels in complex field environments, this study used a UAV to collect images of maize male tassels under different environmental factors in the experimental field and then constructed and formed the ESG-YOLO detection model based on the YOLOv7 model by using GELU as the activation function instead of the original SiLU and by adding a dual ECA attention mechanism and an SPD-Conv module. And then, through the model to identify and detect the male tassel, the model’s average accuracy reached a mean value (mAP) of 93.1%; compared with the YOLOv7 model, its average accuracy mean value (mAP) is 2.3 percentage points higher. Its low-resolution image and small object target detection is excellent, and it can be more intuitive and fast to obtain the maize male tassel density from automatic identification surveys. It provides an effective method for high-precision and high-efficiency identification of maize male tassel phenotypes in the field, and it has certain application value for maize growth potential, yield, and density assessment. Full article

(This article belongs to the Special Issue The Applications of Deep Learning in Smart Agriculture)

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11 pages, 604 KiB

Open AccessEditor’s ChoiceReview

Commercial Cultivation of Edible Halophytes: The Issue of Oxalates and Potential Mitigation Options

by Bronwyn J. Barkla, Tania Farzana and Terry J. Rose

Agronomy 2024, 14(2), 242; https://doi.org/10.3390/agronomy14020242 - 24 Jan 2024

Cited by 6 | Viewed by 1835

Abstract

Saline agriculture, including the commercial cultivation of edible halophytes, is expanding rapidly to address the increase in salinised soil due to natural and man-made causes, the decline in availability of fresh water, the increased use of poor-quality water, and increasing food insecurity. Halophytes, [...] Read more.

Saline agriculture, including the commercial cultivation of edible halophytes, is expanding rapidly to address the increase in salinised soil due to natural and man-made causes, the decline in availability of fresh water, the increased use of poor-quality water, and increasing food insecurity. Halophytes, as food crops, offer an innovative new opportunity in agriculture, many being highly nutritious and containing bioactive compounds. However, the commercial production of edible halophytes to meet emerging consumer demands faces several challenges. This review examines the market potential for the expansion of edible halophyte crops and the challenges of consumer acceptance and production capacity beyond wild harvest. In addition to beneficial compounds, halophytes are known to contain several anti-nutrient compounds, which can have negative health consequences. In edible halophytes, oxalates are of particular concern. However, research has shown that there are ways to mitigate the accumulation of oxalate through processing, agronomic practice, and genetic engineering. These approaches are presented as potential strategies that can be used in commercial farming systems to reduce the levels of this compound. Full article

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18 pages, 2710 KiB

Open AccessEditor’s ChoiceReview

Life Cycle Assessment of Hydrothermal Carbonization: A Review of Product Valorization Pathways

by Andrea Ogunleye, Joseph Flora and Nicole Berge

Agronomy 2024, 14(2), 243; https://doi.org/10.3390/agronomy14020243 - 24 Jan 2024

Cited by 4 | Viewed by 2789

Abstract

Hydrothermal carbonization (HTC) has the potential to be a sustainable and environmentally beneficial approach for organic waste treatment. It is likely that HTC product use will dictate the viability of large-scale HTC facilities; therefore, understanding the viability and environmental implications associated with HTC [...] Read more.

Hydrothermal carbonization (HTC) has the potential to be a sustainable and environmentally beneficial approach for organic waste treatment. It is likely that HTC product use will dictate the viability of large-scale HTC facilities; therefore, understanding the viability and environmental implications associated with HTC product valorization pathways is critical. The overall goal of this review is to gain an understanding of how HTC product valorization is currently being modeled in life cycle assessment studies, and to use such information to assess current research and/or data needs associated with product valorization. To accomplish this, a review of existing HTC literature was conducted and used to assess the current state of knowledge surrounding the environmental implications of HTC product use. From this review of the literature, it is clear that potential exists for HTC product valorization. To realize this potential in a full-scale application, research gaps and data needs were identified that included a system-level integration to evaluate location-specific information as well as more extensive characterization of the impact of HTC product properties on valorization impacts. Full article

(This article belongs to the Special Issue Innovative Hydrothermal Systems to Valorize Agricultural Residuals for Sustainable Crop Production and Environmental System)

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18 pages, 8310 KiB

Open AccessEditor’s ChoiceArticle

Estimating the Light Interception and Photosynthesis of Greenhouse-Cultivated Tomato Crops under Different Canopy Configurations

by Yue Zhang, Michael Henke, Yiming Li, Zhouping Sun, Weijia Li, Xingan Liu and Tianlai Li

Agronomy 2024, 14(2), 249; https://doi.org/10.3390/agronomy14020249 - 24 Jan 2024

Cited by 5 | Viewed by 2448

Abstract

Understanding the spatial heterogeneity of light and photosynthesis distribution within a canopy is crucial for optimizing plant growth and yield, especially in the context of greenhouse structures. In previous studies, we developed a 3D functional-structural plant model (FSPM) of the Chinese solar greenhouse [...] Read more.

Understanding the spatial heterogeneity of light and photosynthesis distribution within a canopy is crucial for optimizing plant growth and yield, especially in the context of greenhouse structures. In previous studies, we developed a 3D functional-structural plant model (FSPM) of the Chinese solar greenhouse (CSG) and tomato plants, in which the greenhouse was reconstructed as a 3D mockup and implemented in the virtual scene. This model, which accounts for various environmental factors, allows for precise calculations of radiation, temperature, and photosynthesis at the organ level. This study focuses on elucidating optimal canopy configurations for mechanized planting in greenhouses, building upon the commonly used north–south (N–S) orientation by exploring the east–west (E–W) orientation. Investigating sixteen scenarios with varying furrow distance (1 m, 1.2 m, 1.4 m, 1.6 m) and row spacing (0.3 m, 0.4 m, 0.5 m, 0.6 m), corresponding to 16 treatments of plant spacing, four planting patterns (homogeneous row, double row, staggered row, incremental row) and two orientations were investigated. The results show that in Shenyang city, an E–W orientation with the path width = 0.5 (furrow distance + row distance) = 0.8 m (homogeneous row), and a plant distance of 0.32 m, is the optimal solution for mechanized planting at a density of 39,000 plants/ha. Our findings reveal a nuanced understanding of how altering planting configurations impacts the light environment and photosynthesis rate within solar greenhouses. Looking forward, these insights not only contribute to the field of CSG mechanized planting, but also provide a basis for enhanced CSG planting management. Future research could further explore the broader implications of these optimized configurations in diverse geographic and climatic conditions. Full article

(This article belongs to the Topic Advances in Crop Simulation Modelling)

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20 pages, 3203 KiB

Open AccessEditor’s ChoiceArticle

Poly-Glutamic Acid Promotes the Growth and the Accumulation of Main Medicinal Components in Salvia miltiorrhiza

by Changjuan Shan, Xiaoqing Zhang, Yi Luo and Dongfeng Yang

Agronomy 2024, 14(2), 252; https://doi.org/10.3390/agronomy14020252 - 24 Jan 2024

Cited by 5 | Viewed by 1352

Abstract

Salvia miltiorrhiza Bunge is a traditional medicinal plant in China and poly-glutamic acid (PGA) is a valuable biopolymer. However, it is unclear whether PGA promotes growth and the accumulation of main medicinal components in S. miltiorrhiza. To elucidate this scientific question, the [...] Read more.

Salvia miltiorrhiza Bunge is a traditional medicinal plant in China and poly-glutamic acid (PGA) is a valuable biopolymer. However, it is unclear whether PGA promotes growth and the accumulation of main medicinal components in S. miltiorrhiza. To elucidate this scientific question, the influences of PGA on the growth, physiological characteristics, and accumulation of main medicinal components in S. miltiorrhiza were explored through a pot experiment. The results revealed that PGA significantly promoted basal diameter, plant height, shoot and root biomass, as well as root volume, compared with control. PGA also increased SPAD value, net photosynthetic rate, actual and maximum photochemical efficiency of photosynthetic system II, photochemical quenching, and electronic transfer rate. Meanwhile, PGA increased transpiration rate, stomatal conductance, water use efficiency, leaf relative water content, and the contents of soluble protein, soluble sugar, and proline. Furthermore, PGA increased the activities of antioxidant enzymes and the contents of antioxidants. The above findings imply that PGA facilitated S. miltiorrhiza growth by enhancing photosynthetic performance, water metabolism, and antioxidant capacity. Additionally, PGA significantly improved the yield of rosmarinic acid, salvianolic acid B, dihydrotanshinone, cryptotanshinone, tanshinone I, and tanshinone ⅡA in roots by up-regulating the transcript levels of genes responsible for their biosynthesis. Our findings indicated that PGA promoted S. miltiorrhiza growth and the accumulation of main medicinal components in roots. Full article

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39 pages, 1403 KiB

Open AccessEditor’s ChoiceReview

Research Needs and Pathways to Advance Hydrothermal Carbonization Technology

by Chau Huyen Dang, Giovanna Cappai, Jae-Wook Chung, Changyoon Jeong, Beatrice Kulli, Filippo Marchelli, Kyoung S. Ro and Silvia Román

Agronomy 2024, 14(2), 247; https://doi.org/10.3390/agronomy14020247 - 24 Jan 2024

Cited by 12 | Viewed by 3129

Abstract

Hydrothermal carbonization (HTC) is a proven cost-effective and energy-efficient method for waste management and value-added product recovery. There are, however, several issues that require further improvement or research. Identifying the strengths and weaknesses of HTC in comparison to traditional pyrolysis is crucial for [...] Read more.

Hydrothermal carbonization (HTC) is a proven cost-effective and energy-efficient method for waste management and value-added product recovery. There are, however, several issues that require further improvement or research. Identifying the strengths and weaknesses of HTC in comparison to traditional pyrolysis is crucial for scientists to choose between them or use both (complementary) to achieve specific product properties. Additionally, sharing information on diverse modeling approaches and scales is crucial to enhance the robustness and universality of HTC process models. In addition, the study on the applicability of hydrochars on target applications such as soil amendment is crucial to give back nutrients to soils and face the dependence on finite specific feedstocks in this field. Also, proper management of the process by-products, especially process water, must be addressed to improve the carbon and hydric footprint of the process. Reviewing the suitability of HTC to treat specific challenging wastes, whose strength is not related to their calorific value but to their nutrient composition (i.e., manures), is also an appealing topic for HTC research. This paper aims to tackle the above-mentioned issues through an updated review and discussion of research gaps that require further investigation. Full article

(This article belongs to the Special Issue Innovative Hydrothermal Systems to Valorize Agricultural Residuals for Sustainable Crop Production and Environmental System)

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21 pages, 5399 KiB

Open AccessEditor’s ChoiceArticle

Metabolomics and Physiological Methods Revealed the Effects of Drought Stress on the Quality of Broomcorn Millet during the Flowering Stage

by Jiangling Ren, Yuhan Liu, Jiao Mao, Yuanmeng Xu, Mengyao Wang, Yulu Hu, Shu Wang, Sichen Liu, Zhijun Qiao and Xiaoning Cao

Agronomy 2024, 14(2), 236; https://doi.org/10.3390/agronomy14020236 - 23 Jan 2024

Cited by 5 | Viewed by 1891

Abstract

The flowering stage is a critical period for water sensitivity and quality formation of broomcorn millets. However, the effects and mechanisms of drought stress on the quality formation of broomcorn millets are not clear. We used the drought-resistant variety Hequ red millet (H) [...] Read more.

The flowering stage is a critical period for water sensitivity and quality formation of broomcorn millets. However, the effects and mechanisms of drought stress on the quality formation of broomcorn millets are not clear. We used the drought-resistant variety Hequ red millet (H) and the drought-sensitive variety Yanshu No. 10 (Y) were used as materials for drought stress treatment during the flowering stage, metabolomics and physiological methods were used to study the differences in protein, starch, amino acids, medium and medium-long chain fatty acids, and their response characteristics to drought in broomcorn millet. The results showed that different genotypes of broomcorn millets exhibited different response mechanisms in the face of drought stress. In Hequ red millet, drought stress significantly increased the contents of amylopectin (2.57%), pyridoxine (31.89%), and anthocyanin, and significantly decreased the contents of water-soluble protein (5.82%), glutelin (10.07%), thiamine (14.95%) and nicotinamide (23.01%). In Yanshu No. 10, drought significantly decreased amylose by 6.05%, and significantly increased riboflavin and nicotinamide contents by 21.11% and 32.59%. Correlation analysis showed that total starch and amylose were highly significantly positively correlated with methyl palmitate; negatively correlated with amylopectin, vitamins, proteins, free amino acids, and medium-long chain fatty acids; and amylopectin was significantly positively correlated with water-soluble protein, riboflavin, and pyridoxine. Water-soluble protein and glutelin were significantly positively correlated with most free amino acids, medium-long chain fatty acids, and nicotinamide. Thiamine showed significant positive correlation with nicotinamide and significant negative correlation with pyridoxine. Riboflavin was significantly positively correlated with nicotinamide, pyridoxine, and water-soluble protein, and pyridoxine was significantly positively correlated with water-soluble protein. Hequ red millet transforms into amylopectin by consuming water-soluble protein and glutelin, and improves drought resistance by accumulating pyridoxine, and changes its physicochemical properties by decreasing the content of amylose and protein and elevating the content of amylopectin. Yanshu No. 10 resisted drought by catabolizing lipids to produce fatty acids and by consuming amylose for conversion into other metabolites. The present study helps to understand the response of the nutritional quality of millets to drought stress at the flowering stage and provides a theoretical basis for the selection and breeding of superior varieties of millets and drought resistance research. Full article

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11 pages, 1776 KiB

Open AccessEditor’s ChoiceArticle

Effects of Different Proportions of Organic Fertilizer Replacing Chemical Fertilizer on Soil Nutrients and Fertilizer Utilization in Gray Desert Soil

by Weidan Lu, Zhiqiang Hao, Xiaolong Ma, Jianglong Gao, Xiaoqin Fan, Jianfu Guo, Jianqiang Li, Ming Lin and Yuanhang Zhou

Agronomy 2024, 14(1), 228; https://doi.org/10.3390/agronomy14010228 - 22 Jan 2024

Cited by 21 | Viewed by 6585

Abstract

Organic fertilizer can improve soil management and alleviate soil nutrient loss caused by excessive fertilization. This study determines a fertilization scheme that can achieve high and stable crop yield and effective soil fertilization by exploring the effects of different organic fertilizer proportions on [...] Read more.

Organic fertilizer can improve soil management and alleviate soil nutrient loss caused by excessive fertilization. This study determines a fertilization scheme that can achieve high and stable crop yield and effective soil fertilization by exploring the effects of different organic fertilizer proportions on soil nutrient content, fertilizer utilization rate, and wheat yield. The experiment was conducted from 2018 to 2020 using the Xinchun 38 wheat variety and gray desert soil. The experiment used six treatments: no fertilizer (CK), with normal nitrogen and phosphorus fertilizer (CF). The amount of conventional chemical nitrogen fertilizer was reduced by 6%, 12%, 18%, and 24%, respectively, and supplemented with organic nitrogen fertilizer of the same proportion. The experimental treatment codes were SF6, SF12, SF18, and SF24, respectively. Plant samples from six wheat growth stages and 0–20 cm soil samples were collected to analyze the nitrogen and phosphorus content and organic matter; dry matter accumulation, crop yield, and yield components were measured at the harvest stage. Soil available nitrogen, phosphorus, potassium, and soil organic matter contents increased with the replacement ratio of organic fertilizer after three consecutive years of application. The available nutrients and organic matter in soil treated with SF18 and SF24 were significantly higher than those in CK and CF. The dry matter accumulation and nutrient accumulation of wheat increased with increasing organic fertilizer replacement rates of SF18 and SF24, respectively. Nitrogen and phosphorus fertilizer utilization rates, partial productivity, and agricultural use efficiency also increased, with the SF18 and SF24 treatments having higher organic fertilizer replacement rates than those in the other treatments. The number of ears, 1000-grain weight, and yield of wheat treated with SF18 treatment produced the best results. Therefore, continuously using organic fertilizer as a partial replacement for conventional fertilizer can increase wheat growth and soil nutrient availability, which can improve the utilization rate of fertilizer, thereby achieving stability and even a significant increase in yield. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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12 pages, 2118 KiB

Open AccessEditor’s ChoiceArticle

The Effects of Soil Salt Stress on the Nitrogen Uptake, Yield Response and Nitrogen Use Efficiency of Cotton in Arid Areas

by Tong Heng, Yingjie Ma, Pengrui Ai, Zhenyue Liu, Miao Wu and Changjiang Liu

Agronomy 2024, 14(1), 229; https://doi.org/10.3390/agronomy14010229 - 22 Jan 2024

Cited by 5 | Viewed by 2420

Abstract

Soil salinity is a major soil threat, causing severe environmental problems. Soil salt stress limits N uptake and cotton growth, especially in arid regions. However, the mechanism underlying stress tolerance in cotton plants under different soil salinity levels has not been fully elucidated. [...] Read more.

Soil salinity is a major soil threat, causing severe environmental problems. Soil salt stress limits N uptake and cotton growth, especially in arid regions. However, the mechanism underlying stress tolerance in cotton plants under different soil salinity levels has not been fully elucidated. Therefore, the aim of this study was to examine the proportion and mechanism of cotton N uptake and transport under salt stress using the ¹⁵N isotope labeling technique. Cotton plants were grown in four undisturbed loamy soils (CK, non-salinity, <2 dS m⁻¹; C1, low salinity, 2–4 dS m⁻¹; C2, mid-salinity, 4–8 dS m⁻¹; and C3, high salinity, 8–15 dS m⁻¹) in the test pit experiments. The findings indicated that the cotton N uptake was limited by the soil salt stress and total N content, and the cotton ¹⁵N use efficiency decreased by 25–27% with increasing salinity (>4.0 dS m⁻¹). The N transported to cotton from the 0–20 cm soil layer in C1 treatment was higher than from the 40–60 cm layer. Furthermore, the cotton fruit cultivated in C1 exhibited a notably elevated dry matter content compared to those cultivated in the control treatment. As the soil salt stress increased from the control treatment to C1, the cotton stems and fruits demonstrated a gradual enhancement in their N uptake and regulatory capabilities, albeit with a slight decrease observed in the leaves. These findings emphasize that soil salt stress diminishes cotton nitrogen uptake and transport, potentially exacerbating nitrogen pollution in the absence of optimized nitrogen fertilization. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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18 pages, 3164 KiB

Open AccessEditor’s ChoiceArticle

Arbuscular Mycorrhizal Fungi as Biofertilizers to Increase the Plant Quality of Sour-Orange Seedlings

by Josefa María Navarro and Asunción Morte

Agronomy 2024, 14(1), 230; https://doi.org/10.3390/agronomy14010230 - 22 Jan 2024

Cited by 7 | Viewed by 3315

Abstract

In addressing the agricultural challenges posed by climate change, the use of biofertilizers, derived from living organisms, promotes environmentally friendly crop cultivation, and represents an adaptive strategy for sustainable agriculture in the face of climate uncertainty. Careful selection of the arbuscular mycorrhizal fungus [...] Read more.

In addressing the agricultural challenges posed by climate change, the use of biofertilizers, derived from living organisms, promotes environmentally friendly crop cultivation, and represents an adaptive strategy for sustainable agriculture in the face of climate uncertainty. Careful selection of the arbuscular mycorrhizal fungus (AMF) would represent a crucial step in mycorrhizal inoculation, considering the varying levels of compatibility between the AMF and the host plant. This study aimed to assess the impact of two AMF species that are prevalent in citrus soils of south-eastern Spain (Rhizophagus irregularis and Funneliformis mosseae) on the Citrus aurantium seedlings’ behavior. Sour-orange plants showed a high mycorrhizal dependence regardless of the specific AMF species. Both R. irregularis and F. mosseae fungi exhibited high colonization percentages, with R. irregularis outperforming F. mosseae in root colonization. Inoculation with both AMF yielded notable growth improvements, but R. irregularis exhibited higher positive effects in the long term. The heightened P nutrition and increased chlorophyll concentration significantly enhanced the performance of AMF-inoculated plants. With F. mosseae, plants showed more pronounced improvements in P nutrition and a stronger correlation of their dry mass with P concentration; however, in general, inoculation with R. irregularis produced a higher sour-orange-plant performance. Both R. irregularis and F. mosseae fungi produced strong positive effects in sour-orange growth, which positioned them as viable biofertilizer options. These results can contribute to enhancing understanding for the development of an improved design of biofertilizers used in regions that are vulnerable to climate change, such as south-eastern Spain. This promotes a shift towards more sustainable and environmentally friendly agricultural practices by reducing dependence on chemical fertilizers. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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11 pages, 1389 KiB

Open AccessEditor’s ChoiceArticle

Effects of Pre-Germinative Treatments and Temperatures on Tassel Hyacinth [Muscari comosum (L.) Mill.] Seeds

by Donato Castronuovo, Loriana Cardone and Vincenzo Candido

Agronomy 2024, 14(1), 225; https://doi.org/10.3390/agronomy14010225 - 21 Jan 2024

Cited by 2 | Viewed by 1587

Abstract

Muscari comosum (L.) Mill. is a spontaneous plant that grows in the whole Mediterranean area, including the Basilicata and Puglia regions (southern Italy), where it has received inclusion in the Italian National List for Traditional Agri-Food Product (TAP). The food and medicinal uses [...] Read more.

Muscari comosum (L.) Mill. is a spontaneous plant that grows in the whole Mediterranean area, including the Basilicata and Puglia regions (southern Italy), where it has received inclusion in the Italian National List for Traditional Agri-Food Product (TAP). The food and medicinal uses of bulb are ancient due to its antioxidant properties and high variety of nutrients, such as starch, sugars, and minerals. Muscari seed is characterized by morpho-physiological dormancy, and in order to achieve uniform germination, some pre-germinative treatments are needed. In this research, the effects of hydro-priming and osmo-priming, i.e., PEG 8000 and KNO₃, as well as three germination temperatures (4, 10, and 20 °C), have been evaluated. In general, the average results pointed out that the pre-treatments increased the germination index (GI) by 5% and the germination percentage (GP) by 3% compared to the no-primed control. The germination temperature of 10 °C significantly reduced the median germination time (T50) by 5.4 days and the mean germination time (MGT) by 5 days compared to temperature at 4 °C. In particular, the best results were obtained by “hydro-priming treatment × 10 °C” interaction, in terms of T50 (34.9 days) and MGT (36.3 days). This combination decreased the T50 by 10.5 days and the MGT by 9.6 days compared to the “control × 4 °C” interaction. Pearson’s correlation matrix results highlighted a significant positive link between T50 and MGT (r = 0.993). In conclusion, these techniques enhanced the germination potential so that the use of pre-treated seeds could be included in a cultivation protocol to improve the germination phase and satisfy the growing demand for Italian bulbs. Full article

(This article belongs to the Section Horticultural and Floricultural Crops)

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16 pages, 3571 KiB

Open AccessEditor’s ChoiceArticle

Detection and Analysis of Chili Pepper Root Rot by Hyperspectral Imaging Technology

by Yuanyuan Shao, Shengheng Ji, Guantao Xuan, Yanyun Ren, Wenjie Feng, Huijie Jia, Qiuyun Wang and Shuguo He

Agronomy 2024, 14(1), 226; https://doi.org/10.3390/agronomy14010226 - 21 Jan 2024

Cited by 7 | Viewed by 2465

Abstract

The objective is to develop a portable device capable of promptly identifying root rot in the field. This study employs hyperspectral imaging technology to detect root rot by analyzing spectral variations in chili pepper leaves during times of health, incubation, and disease under [...] Read more.

The objective is to develop a portable device capable of promptly identifying root rot in the field. This study employs hyperspectral imaging technology to detect root rot by analyzing spectral variations in chili pepper leaves during times of health, incubation, and disease under the stress of root rot. Two types of chili pepper seeds (Manshanhong and Shanjiao No. 4) were cultured until they had grown two to three pairs of true leaves. Subsequently, robust young plants were infected with Fusarium root rot fungi by the root-irrigation technique. The effective wavelength for discriminating between distinct stages was determined using the successive projections algorithm (SPA) after capturing hyperspectral images. The optimal index related to root rot between each normalized difference spectral index (NDSI) was obtained using the Pearson correlation coefficient. The early detection of root rot illness can be modeled using spectral information at effective wavelengths and in NDSI, together with the application of partial least squares discriminant analysis (PLS-DA), least squares support vector machine (LSSVM), and back-propagation (BP) neural network technology. The SPA-BP model demonstrates outstanding predictive capabilities compared with other models, with a classification accuracy of 92.3% for the prediction set. However, employing SPA to acquire an excessive number of efficient wave-lengths is not advantageous for immediate detection in practical field scenarios. In contrast, the NDSI (R₄₄₅, R₄₃₃)-BP model uses only two wavelengths of spectral information, but the prediction accuracy can reach 89.7%, which is more suitable for rapid detection of root rot. This thesis can provide theoretical support for the early detection of chili root rot and technical support for the design of a portable root rot detector. Full article

(This article belongs to the Special Issue Innovation of Intelligent Detection and Pesticide Application Technology for Horticultural Crops)

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21 pages, 2103 KiB

Open AccessEditor’s ChoiceArticle

Comprehensive Morphometric and Biochemical Characterization of Seven Basil (Ocimum basilicum L.) Genotypes: Focus on Light Use Efficiency

by Ferdinando Branca, Simone Treccarichi, Giuseppe Ruberto, Agatino Renda and Sergio Argento

Agronomy 2024, 14(1), 224; https://doi.org/10.3390/agronomy14010224 - 20 Jan 2024

Cited by 4 | Viewed by 2382

Abstract

The choice of basil (Ocimum basilicum L.) genotypes determines key attributes such as yield, flavor, and adaptability, contributing significantly to the overall success and sustainability of basil cultivation practices. As the primary aim of this study, seven basil accessions were characterized for [...] Read more.

The choice of basil (Ocimum basilicum L.) genotypes determines key attributes such as yield, flavor, and adaptability, contributing significantly to the overall success and sustainability of basil cultivation practices. As the primary aim of this study, seven basil accessions were characterized for both their growth performance and biochemical profile of volatile compounds, enabling the differentiation among distinct chemotypes. As secondary objectives, growth performance and production were evaluated under natural solar radiation conditions (SR100) and with a 30% reduction in solar radiation using a net (SR70). Light use efficiency (LUE) determination revealed the plants’ biomass production capability under different solar radiation (SR) conditions. Genotypes A, B, C, and G were characterized by a high levels of linalool, which is typically associated with the “pesto” sauce smell. Lemon basil D exhibited a different chemotype due to the presence of neral and geranial. E and F displayed a different chemotype due to the higher concentration of α-bergamotene. The total fresh harvested biomass was significantly higher in SR70 than SR100 conditions. The second harvest in both SR conditions was the most productive one, while genotype E under SR70 displayed the highest yield. The landraces D and E showed the highest LUE values, indicating their capability in converting the solar radiation into fresh biomass. Plants grown in SR70 conditions registered significantly higher values of plant height, number of branches, and leaf weight. This work aimed to provide valuable insights into the selection of basil genotypes suitable for sustainable agriculture. Conversely, it lays the basis for cultivation aspects pertaining to the crop’s adaptability in peri-urban, marginal lands, which are characterized by limited solar radiation. Full article

(This article belongs to the Section Horticultural and Floricultural Crops)

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22 pages, 2015 KiB

Open AccessEditor’s ChoiceArticle

The Content of Antioxidant Compounds and VOCs in Sorghum Grain Grown in Central and Eastern Europe

by Anna Przybylska-Balcerek, Jakub Frankowski, Dominika Sieracka, Tereza Sázavská, Stanisław Wacławek, Barbara Klaudia Raczak, Lidia Szwajkowska-Michałek, Maciej Buśko, Małgorzata Graczyk, Grażyna Niedziela and Kinga Stuper-Szablewska

Agronomy 2024, 14(1), 217; https://doi.org/10.3390/agronomy14010217 - 19 Jan 2024

Cited by 5 | Viewed by 1817

Abstract

Sorghum is a plant belonging to the Poaceae family. It is drought-resistant and has low soil requirements. In the face of climate change, it is increasingly cultivated in Europe. Poland is a country with great agricultural potential; it is thus important to develop [...] Read more.

Sorghum is a plant belonging to the Poaceae family. It is drought-resistant and has low soil requirements. In the face of climate change, it is increasingly cultivated in Europe. Poland is a country with great agricultural potential; it is thus important to develop effective and economic methods of agricultural production, which is confirmed by the introduction of sorghum into cultivation. The aim of this study was to characterize the composition of bioactive compounds (i.e., phenolic acids, flavonoids, carotenoids, and phytosterols) and VOCs in sorghum grain of two varieties, i.e., white ‘Sweet Caroline’ and red ‘Sweet Susana’ grown in the temperate climate (Pętkowo, Poland (52°12′40″ N 17°15′31″ E)). The following tests were carried out: analysis of phenolic acids, flavonoids, carotenoids, phytosterols, antioxidant activity (ABTS), free phenolic acids (FPAs); elemental analysis; and water, fat and starch content analysis. Based on the conducted research, it was concluded that Poland has appropriate conditions for growing sorghum, as the content of bioactive (antioxidant) compounds was at a similar level to those grown in tropical and subtropical climates. Of the nine phenolic acids and seven flavonoids determined, the highest concentrations in both sorghum grain varieties were found for ferulic, p-coumaric and protocatechuic acids. The content of ferulic acid was three times higher in Sweet Caroline grains than in Sweet Susana grains. Differences in the content of these compounds may be the result of genetic differences between the Sweet Susana and Sweet Caroline varieties. Full article

(This article belongs to the Special Issue Recent Insights in Sustainable Agriculture and Nutrient Management)

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18 pages, 3754 KiB

Open AccessEditor’s ChoiceArticle

Comparative Analysis of the Performance of a Chain Mower and Tools That Perform Under-Row Weed Control with Tillage in the Vineyard

by Lorenzo Gagliardi, Sofia Matilde Luglio, Andrea Peruzzi, Marco Fontanelli, Christian Frasconi and Michele Raffaelli

Agronomy 2024, 14(1), 206; https://doi.org/10.3390/agronomy14010206 - 17 Jan 2024

Cited by 2 | Viewed by 1552

Abstract

In the Mediterranean area, vineyard soils are often characterized by a high stone content. In these contexts, where tools commonly adopted for under-row weed control are frequently damaged, the utilization of a chain mower could be a preferable alternative. This research aims to [...] Read more.

In the Mediterranean area, vineyard soils are often characterized by a high stone content. In these contexts, where tools commonly adopted for under-row weed control are frequently damaged, the utilization of a chain mower could be a preferable alternative. This research aims to compare a modified mower with chains with other tools commonly employed that control weeds through tillage, such as motorized discs, blade weeder, and rotary star hoe. Weed control effectiveness, effects on weed flora composition, soil compaction, and operative efficiencies were evaluated. The chain mower allowed us to obtain encouraging results of weed biomass reduction (55.4 and 25.4%, between and around vine trunks, respectively), weed height reduction (35.9%), and weed cover reduction (79.2%), comparable to the other tools. All the tools showed a lower weed control efficacy around vine trunks rather than between them (weed biomass reductions of 24.8% and 52.6%, respectively). Results regarding the effect on weed flora composition seem to confirm this trend. Despite the higher chain mower field time (3.78 h ha⁻¹) and fuel consumption (24.24 kg ha⁻¹) compared to the blade weeder and the rotary star hoe, its versatility in stony soil and its lower impact on soil (soil penetration resistances of 1602.42 and 2262.83 kPa in 2022 and 2023, respectively) compared to the other tools make it a potentially advantageous implement for under-row weed management in vineyards. Further studies could be useful to improve chain mower performance, particularly around vine trunks, by evaluating in different planting layouts different dimensions of both the cutting element and feeler, which allows the vine-skipping mechanism. Full article

(This article belongs to the Special Issue Smart Strategies and Technologies for Sustainability and Biodiversity in Herbaceous and Horticultural Crops—2nd Edition)

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13 pages, 982 KiB

Open AccessEditor’s ChoiceReview

The Archaeology of Field Systems in Al-Andalus

by Helena Kirchner

Agronomy 2024, 14(1), 196; https://doi.org/10.3390/agronomy14010196 - 16 Jan 2024

Cited by 1 | Viewed by 2510

Abstract

The Berber and Arab conquest of the Iberian Peninsula in 711 C.E. led to a profound transformation of the agricultural landscape. The layout of the irrigated areas, both rural and urban, is recognisable because it is the result of social and technological choices. [...] Read more.

The Berber and Arab conquest of the Iberian Peninsula in 711 C.E. led to a profound transformation of the agricultural landscape. The layout of the irrigated areas, both rural and urban, is recognisable because it is the result of social and technological choices. But irrigated agriculture was not the only option in Al-Andalus. Rainfed agriculture is supposed to have been the main form of agriculture in large areas of the centre and west of the peninsula, although the field systems have been scarcely identified. In regions where irrigation was the preferred option, rainfed crops were complementary. In regions where dry farming was the only possible agriculture, there were settlement networks linked to livestock breeding and to droveways and pasture areas. The original selections made by the Berber and Arab farmers can still be recognized despite the expansion that has mainly taken place since modern times. However, the more recent and destructive capitalist agriculture is erasing the last vestiges of the Andalusi agricultural landscape. Full article

(This article belongs to the Special Issue Archaeology and Agriculture)

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21 pages, 14915 KiB

Open AccessEditor’s ChoiceArticle

A Method for Tomato Plant Stem and Leaf Segmentation and Phenotypic Extraction Based on Skeleton Extraction and Supervoxel Clustering

by Yaxin Wang, Qi Liu, Jie Yang, Guihong Ren, Wenqi Wang, Wuping Zhang and Fuzhong Li

Agronomy 2024, 14(1), 198; https://doi.org/10.3390/agronomy14010198 - 16 Jan 2024

Cited by 14 | Viewed by 3566

Abstract

To address the current problem of the difficulty of extracting the phenotypic parameters of tomato plants in a non-destructive and accurate way, we proposed a method of stem and leaf segmentation and phenotypic extraction of tomato plants based on skeleton extraction and supervoxel [...] Read more.

To address the current problem of the difficulty of extracting the phenotypic parameters of tomato plants in a non-destructive and accurate way, we proposed a method of stem and leaf segmentation and phenotypic extraction of tomato plants based on skeleton extraction and supervoxel clustering. To carry out growth and cultivation experiments on tomato plants in a solar greenhouse, we obtained multi-view image sequences of the tomato plants to construct three-dimensional models of the plant. We used Laplace’s skeleton extraction algorithm to extract the skeleton of the point cloud after removing the noise points using a multi-filtering algorithm, and, based on the plant skeleton, searched for the highest point path, height constraints, and radius constraints to separate the stem from the leaf. At the same time, a supervoxel segmentation method based on Euclidean distance was used to segment each leaf. We extracted a total of six phenotypic parameters of the plant: height, stem diameter, leaf angle, leaf length, leaf width and leaf area, using the segmented organs, which are important for the phenotype. The results showed that the average accuracy, average recall and average F1 scores of the stem and leaf segmentation were 0.88, 0.80 and 0.84, and the segmentation indexes were better than the other four segmentation algorithms; the coefficients of determination between the measurement values of the phenotypic parameters and the real values were 0.97, 0.84, 0.88, 0.94, 0.92 and 0.93; and the root-mean-square errors were 2.17 cm, 0.346 cm, 5.65°, 3.18 cm, 2.99 cm and 8.79 cm². The measurement values of the proposed method had a strong correlation with the actual values, which could satisfy the requirements of daily production and provide technical support for the extraction of high-throughput phenotypic parameters of tomato plants in solar greenhouses. Full article

(This article belongs to the Section Agricultural Biosystem and Biological Engineering)

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26 pages, 5802 KiB

Open AccessEditor’s ChoiceReview

Phosphorus HotSpots in Crop Plants Production on the Farm—Mitigating Critical Factors

by Witold Grzebisz, Alicja Niewiadomska, Jarosław Potarzycki and Agnieszka Andrzejewska

Agronomy 2024, 14(1), 200; https://doi.org/10.3390/agronomy14010200 - 16 Jan 2024

Cited by 6 | Viewed by 2321

Abstract

Phosphorus resources, both in phosphate rocks and in the soil, are limited. However, effective food production is not possible without the use of P fertilizers. Recognizing and eliminating or at least ameliorating factors (hot spots) that interfere with the uptake and use of [...] Read more.

Phosphorus resources, both in phosphate rocks and in the soil, are limited. However, effective food production is not possible without the use of P fertilizers. Recognizing and eliminating or at least ameliorating factors (hot spots) that interfere with the uptake and use of phosphorus (P) by crop plants is of key importance for effective use of both P and nitrogen (N) on the farm. Plants have developed many adaptation mechanisms to their environment, i.e., soil low in available phosphorus. The most important ones include the secretion of organic compounds into the rhizosphere and the association of plant roots with microorganisms. A classic example is mycorrhiza. These mechanisms can be used by the farmer to sequentially select plants in the crop rotation. The uptake of inorganic P (P_i) by plants from the soil is reduced by environmental (temperature and water) and soil factors (low content of available phosphorus, soil acidity, soil compaction). These factors are responsible for the growth and size of the root system. Mitigating these negative effects improves the efficiency of phosphorus uptake from the soil. The second group of critical factors, limiting both root growth and availability of phosphorus, can be effectively controlled using simple measures (for example, lime). Knowing this, the farmer must first control the level of soil fertility in the plant’s effective rooting zone and not only in the topsoil. Secondly, the farmer must multiply the productivity of applied mineral fertilizers used through targeted recycling: crop rotation, crop residues, and manure. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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17 pages, 2435 KiB

Open AccessEditor’s ChoiceArticle

Removal of Crop Ion Components in Relation to Mollisol Acidification under Long-Term Management

by Ying Xu, Zhenhua Yu, Yansheng Li, Jian Jin, Xingyi Zhang, Guanghua Wang and Xiaobing Liu

Agronomy 2024, 14(1), 191; https://doi.org/10.3390/agronomy14010191 - 15 Jan 2024

Cited by 3 | Viewed by 1281

Abstract

Crop removal of cations and anions is one of the main factors causing soil acidification. Mollisols, also known as black soils, which are inherently neutral soils, have been acidified due to irrational land use. However, the magnitude of acidification of black soils in [...] Read more.

Crop removal of cations and anions is one of the main factors causing soil acidification. Mollisols, also known as black soils, which are inherently neutral soils, have been acidified due to irrational land use. However, the magnitude of acidification of black soils in relation to crop removal under crop rotation and field management remains unclear. In this study, we collect soil samples from 9- and 10-year long-term trials with seven treatments of soybean and corn monoculture, and corn–soybean rotation under different fertilization or straw return in the Mollisol region of Northeast China. Total removal of cations and anions is 371–508 and 92–125 kg ha⁻¹ in corn but 166–250 and 56–82 kg ha⁻¹ in soybean, which leads to the production of 7.06–10.2 kmol ha⁻¹ H⁺ for corn and 4.43–5.77 kmol ha⁻¹ H⁺ for soybean. Among the four cations (K⁺, Ca²⁺, Na⁺, and Mg²⁺) analyzed in different tissues of crops, K⁺ contributes more to the total H⁺ production, where K⁺ in corn stem contributes more than 55% H⁺, while K⁺ in soybean seed contributes more than 64% H⁺. The sum of Ca²⁺ and Mg²⁺ removal for soybean is 37.6–66.9 kg ha⁻¹, 1.26–2.07 times (p < 0.05) greater than for corn. Net H⁺ produced by corn and soybean removal may potentially lead to a soil acidification of 0.053–0.074 and 0.032–0.045 year⁻¹ units pH, respectively. The greater the corn or soybean biomass, the higher the net H⁺ production. Continuous soybean and combination of chemical fertilizer for corn but no chemical fertilizer for soybean reduce the soil pH buffering capacity (pHBC), while other treatments increase the soil pHBC, but there is no effect for continuous corn. Compared to normal corn–soybean rotation, soil pH in 9-year continuous corn declines from 5.76 to 5.63, while 10-year continuous soybean declines from 5.68 to 5.43 (p < 0.05). However, soil pH with chemical fertilizer for corn and dairy manure for soybean increases by 0.60 and 0.89 units (p < 0.05). Changes in pH might not be fully related to crop ion removal. Manure application with crop rotation is an effective approach to alleviate soil acidification. Full article

(This article belongs to the Special Issue Effects of Cover Crops, Crop Rotation, and Intercropping on Natural Soil Fertility)

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16 pages, 4898 KiB

Open AccessEditor’s ChoiceArticle

Native Warm-Season Grass Response to Nitrogen Fertilization

by Eric Bisangwa, Jonathan D. Richwine, Patrick D. Keyser, Amanda J. Ashworth and Forbes R. Walker

Agronomy 2024, 14(1), 180; https://doi.org/10.3390/agronomy14010180 - 14 Jan 2024

Cited by 4 | Viewed by 1657

Abstract

The identification of appropriate nitrogen (N) rates for native warm-season grasses (NWSG) is needed to inform forage management in the southeastern United States. Experiments were conducted in Knoxville and Springfield, TN, from 2015 to 2019, to evaluate dry matter (DM) yield, forage nutritive [...] Read more.

The identification of appropriate nitrogen (N) rates for native warm-season grasses (NWSG) is needed to inform forage management in the southeastern United States. Experiments were conducted in Knoxville and Springfield, TN, from 2015 to 2019, to evaluate dry matter (DM) yield, forage nutritive value (FNV), the influence of temperature and precipitation on yield, and partial factor productivity (PFP) responses. Three NWSG species (big bluestem [BB; Andropogon gerardii Vitman], switchgrass [SG; Panicum virgatum L.], and eastern gamagrass [EG; Tripsacum dactyloides L.]) were grown at each location and harvested twice annually. Five N rates in the form of urea were applied annually in split applications. The yields for all species responded positively to nitrogen (p < 0.001) and the time of harvest (p < 0.001) at both sites, except for BB yield at Springfield; no consistent N effects were observed over years. Nitrogen affected the FNV (p < 0.001) of all species, increasing CP by three to five percentage points (p < 0.001). Yields across all species and locations responded positively to precipitation (p < 0.001) and temperature (p < 0.001). A moderate N amendment (<135 kg N ha⁻¹ yr⁻¹, based on PFP) can enhance the productivity of NWSG, but responses were site-dependent and influenced by temperature and precipitation. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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18 pages, 3719 KiB

Open AccessEditor’s ChoiceArticle

Enhancing Soil Aggregation and Organic Carbon Retention in Greenhouse Vegetable Production through Reductive Soil Disinfestation with Straw and Fertiliser: A Comprehensive Study

by Shanju Wen, Jiaqi Hao, Jiangyuzhuo Wang, Shijuan Xiong, Yuhan Jiang, Yihui Zhu, Yapeng Jiao, Jinglin Yang, Jinli Zhu and Xiaohong Tian

Agronomy 2024, 14(1), 179; https://doi.org/10.3390/agronomy14010179 - 14 Jan 2024

Cited by 5 | Viewed by 2342

Abstract

In greenhouse vegetable production, reductive soil disinfestation (RSD) effectively mitigates soil-borne diseases, yet its impact on the dynamics of soil organic carbon (SOC) has not been adequately examined. This study investigated the distribution of soil aggregates and the organic carbon retention mechanism following [...] Read more.

In greenhouse vegetable production, reductive soil disinfestation (RSD) effectively mitigates soil-borne diseases, yet its impact on the dynamics of soil organic carbon (SOC) has not been adequately examined. This study investigated the distribution of soil aggregates and the organic carbon retention mechanism following intensive RSD treatment. Greenhouse experiments, including control (CK), wheat straw (RSD), and wheat straw with chemical fertilizer (RSD + NP) treatments, indicated augmentation in the formation of macro-aggregates (>2 mm and 0.25–2 mm) under RSD, particularly in the RSD + NP treatment. Silty clay particles transform into macro- and micro-aggregates. Fourier infrared spectroscopy highlighted the augmentation of carbon-containing functional groups in SOC, with aliphatic carbon accumulating in macro-aggregates and aromatic carbon in silt clay. Laboratory culture experiments employing different C/N ratios (RSD1 with wheat straw, RSD2 with kiwifruit branches) underscored the beneficial impact of low C/N ratio organic matter on coarse and fine macro-aggregate content, mean weight diameter, geometric mean diameter, and reduced silt clay. Low C/N ratios enhance SOC retention in large aggregates, while high ratios stabilise micro-aggregate carbon. This research underscores the severe degradation in continuous greenhouse cropping systems and emphasises RSD’s dual benefits—disease prevention and improved SOC retention. Implementing RSD requires careful consideration of organic material choices, specifically their C/N ratios, as a pivotal factor influencing SOC dynamics. Full article

(This article belongs to the Section Soil and Plant Nutrition)

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21 pages, 6051 KiB

Open AccessEditor’s ChoiceArticle

Comparing Laboratory and Satellite Hyperspectral Predictions of Soil Organic Carbon in Farmland

by Haixia Jin, Jingjing Peng, Rutian Bi, Huiwen Tian, Hongfen Zhu and Haoxi Ding

Agronomy 2024, 14(1), 175; https://doi.org/10.3390/agronomy14010175 - 12 Jan 2024

Cited by 9 | Viewed by 2518

Abstract

Mapping soil organic carbon (SOC) accurately is essential for sustainable soil resource management. Hyperspectral data, a vital tool for SOC mapping, is obtained through both laboratory and satellite-based sources. While laboratory data is limited to sample point monitoring, satellite hyperspectral imagery covers entire [...] Read more.

Mapping soil organic carbon (SOC) accurately is essential for sustainable soil resource management. Hyperspectral data, a vital tool for SOC mapping, is obtained through both laboratory and satellite-based sources. While laboratory data is limited to sample point monitoring, satellite hyperspectral imagery covers entire regions, albeit susceptible to external environmental interference. This study, conducted in the Yuncheng Basin of the Yellow River Basin, compared the predictive accuracy of laboratory hyperspectral data (ASD FieldSpec4) and GF-5 satellite hyperspectral imagery for SOC mapping. Leveraging fractional order derivatives (FODs), various denoising methods, feature band selection, and the Random Forest model, the research revealed that laboratory hyperspectral data outperform satellite data in predicting SOC. FOD processing enhanced spectral information, and discrete wavelet transform (DWT) proved effective for GF-5 satellite imagery denoising. Stability competitive adaptive re-weighted sampling (sCARS) emerged as the optimal feature band selection algorithm. The 0.6FOD-sCARS RF model was identified as the optimal laboratory hyperspectral prediction model for SOC, while the 0.8FOD-DWT-sCARS RF model was deemed optimal for satellite hyperspectral prediction. This research, offering insights into farmland soil quality monitoring and strategies for sustainable soil use, holds significance for enhancing agricultural production efficiency. Full article

(This article belongs to the Special Issue Application of Remote Sensing and GIS Technology in Agriculture)

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15 pages, 2554 KiB

Open AccessEditor’s ChoiceArticle

Paddy-Lilium Crop Rotation Improves Potential Beneficial Soil Fungi and Alleviates Soil Acidification in Lilium Cropping Soil

by Li Wen, Fengqiu Huang, Zhongxiu Rao, Kaikai Cheng, Yong Guo and Haiming Tang

Agronomy 2024, 14(1), 161; https://doi.org/10.3390/agronomy14010161 - 11 Jan 2024

Cited by 4 | Viewed by 1751

Abstract

Lilium growth is severely impeded by continuous cropping, and crop rotation is essential to reducing the detrimental effects of monocultures. Soil (0–20 cm) was collected in three Lilium cropping patterns in Longshan County, Hunan Province, including continuous Lilium cropping (Lilium), corn upland rotation [...] Read more.

Lilium growth is severely impeded by continuous cropping, and crop rotation is essential to reducing the detrimental effects of monocultures. Soil (0–20 cm) was collected in three Lilium cropping patterns in Longshan County, Hunan Province, including continuous Lilium cropping (Lilium), corn upland rotation with Lilium (Corn), and paddy rotation with Lilium (Rice). Using Illumina high-throughput sequencing technology, the fungal ribosomal DNA internal-transcribed spacer 1 (ITS1) was examined to evaluate the features of soil fungi communities among three cropping patterns. Crop rotation has an impact on soil properties and the microbial community. Rice soil has a significantly higher pH than Lilium and corn soil, while corn and rice soil have a greater total nitrogen and total phosphorus content than Lilium soil. Rotation cropping clearly shifted the fungi community diversity based on the results of principal coordinate analysis (PCoA) and nonmetric multidimensional scaling (NMDS). Ascomycota was the most prevalent phylum, with the highest levels in Lilium soil. Genetic analysis revealed that paddy rotation led to a clear reduction in or non-detection of eight potentially pathogenic fungal genera and a noticeable accumulation of eight beneficial fungal genera compared to Lilium continuous cropping. Fungi communities and their abundant taxa were correlated with soil pH and nutrients. Altogether, we propose that rice rotation, with its ability to mitigate soil acidification, reducing pathogenic and accumulating beneficial communities, may be an effective strategy for alleviating the continuous cropping barrier. Full article

(This article belongs to the Special Issue Metagenomic Analysis for Unveiling Agricultural Microbiome)

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17 pages, 1038 KiB

Open AccessEditor’s ChoiceReview

Progress in the Management of Rice Blast Disease: The Role of Avirulence and Resistance Genes through Gene-for-Gene Interactions

by Muhammad Usama Younas, Irshad Ahmad, Muhammad Qasim, Zainab Ijaz, Nimra Rajput, Saima Parveen Memon, Waqar UL Zaman, Xiaohong Jiang, Yi Zhang and Shimin Zuo

Agronomy 2024, 14(1), 163; https://doi.org/10.3390/agronomy14010163 - 11 Jan 2024

Cited by 9 | Viewed by 5680

Abstract

Rice is a vital component in the diets of many people worldwide, supplying necessary calories for subsistence. Nevertheless, the yield of this crucial agricultural crop is consistently hindered by a range of biotic stresses. Out of these, rice blast, claused mainly by the [...] Read more.

Rice is a vital component in the diets of many people worldwide, supplying necessary calories for subsistence. Nevertheless, the yield of this crucial agricultural crop is consistently hindered by a range of biotic stresses. Out of these, rice blast, claused mainly by the fungus Magnaporthe oryzae, poses a significant menace to worldwide rice cultivation as well as yield in recent years. The consequences are particularly crucial given the current climate change challenges. In recent decades, substantial progress has been achieved in the development of efficient ways to manage rice blast disease. These procedures entail using a variety of rice genetic resources to find, map, clone, and functionally validate individual resistance (R) genes and quantitative trait loci (QTLs) that provide long-lasting resistance to rice blast disease. Moreover, the replication and practical confirmation of homologous avirulence (Avr) genes in various M. oryzae strains have been crucial in comprehending the fundamental molecular mechanisms of host–pathogen interactions. This article offers a thorough examination of the cloning and functional verification of different R genes and QTLs linked to resistance against rice blast disease. The complex interplay between R–Avr pairings, which contributes to the development of resistance against rice blast throughout a wide range, is thoroughly explained. Finally, this study explores the most recent progress in next-generation sequencing (NGS) and genome editing technologies (GETs), examining their potential uses in improving the treatment of rice blast disease. Full article

(This article belongs to the Section Pest and Disease Management)

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18 pages, 2731 KiB

Open AccessEditor’s ChoiceArticle

Sodium Carbonate Pulping of Wheat Straw—An Alternative Fiber Source for Various Paper Applications

by Friedrich Steffen, Tamas Kordsachia, Tobias Heizmann, Maximilian Paul Eckardt, Yue Chen and Bodo Saake

Agronomy 2024, 14(1), 162; https://doi.org/10.3390/agronomy14010162 - 11 Jan 2024

Cited by 7 | Viewed by 3513

Abstract

European paper mills are currently facing the question of whether recovered paper, their main raw material, will be available in sufficient quantities and an acceptable quality in the future. An alternative to recovered paper or wood fiber is the use of agricultural residues [...] Read more.

European paper mills are currently facing the question of whether recovered paper, their main raw material, will be available in sufficient quantities and an acceptable quality in the future. An alternative to recovered paper or wood fiber is the use of agricultural residues such as wheat straw. Sodium carbonate-based straw pulping processes have the advantage of not requiring recausticizing for chemical recovery, which reduces investment and operating costs. With the addition of oxygen, delignification can be significantly improved to provide pulps suitable for bleaching. This study compares the pulping of wheat straw using sodium carbonate, sodium carbonate + oxygen, and sodium carbonate + sodium hydroxide + oxygen. Pulping parameters such as temperature, retention time, and chemical charge were varied, and their influence on pulp properties was studied. The use of sodium carbonate alone produced pulps with high yields of up to 72% and comparably high burst and compressive strength. The addition of oxygen and small amounts of sodium hydroxide produced pulps with a high initial brightness of 42 %ISO and a low kappa number (18), still at high pulp yields of 62%. These pulps were two-stage bleached to achieve brightness levels of up to 73 %ISO. Full article

(This article belongs to the Special Issue Pretreatment and Bioconversion of Crop Residues II)

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31 pages, 4469 KiB

Open AccessEditor’s ChoiceReview

Molecular Basis and Engineering Strategies for Transcription Factor-Mediated Reproductive-Stage Heat Tolerance in Crop Plants

by Niharika Sharma, Lakshay Sharma, Dhanyakumar Onkarappa, Kalenahalli Yogendra, Jayakumar Bose and Rita A. Sharma

Agronomy 2024, 14(1), 159; https://doi.org/10.3390/agronomy14010159 - 10 Jan 2024

Cited by 2 | Viewed by 3605

Abstract

Heat stress (HS) is a major threat to crop productivity and is expected to be more frequent and severe due to climate change challenges. The predicted increase in global temperature requires us to understand the dimensions of HS experienced by plants, particularly during [...] Read more.

Heat stress (HS) is a major threat to crop productivity and is expected to be more frequent and severe due to climate change challenges. The predicted increase in global temperature requires us to understand the dimensions of HS experienced by plants, particularly during reproductive stages, as crop productivity is majorly dependent on the success of plant reproduction. The impact of HS on crop productivity is relatively less-studied than the other abiotic stresses, such as drought and salinity. Plants have evolved diverse mechanisms to perceive, transduce, respond, and adapt to HS at the molecular, biochemical, and physiological levels. Unraveling these complex mechanisms underlying plant HS response and tolerance would facilitate designing well-informed and effective strategies to engineer HS tolerance in crop plants. In this review, we concisely discuss the molecular impact of HS on plant reproductive processes and yield, with major emphasis on transcription factors. Moreover, we offer vital strategies (encompassing omics studies, genetic engineering and more prominently gene editing techniques) that can be used to engineer transcription factors for enhancing heat tolerance. Further, we highlight critical shortcomings and knowledge gaps in HS tolerance research that should guide future research investigations. Judicious studies and a combination of these strategies could speed up the much-needed development of HS-resilient crop cultivars. Full article

(This article belongs to the Special Issue Genetic Identification and Characterisation of Crop Agronomic Traits and Stress Resistance)

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16 pages, 7320 KiB

Open AccessEditor’s ChoiceArticle

Overexpression of the Rubus idaeus Polygalacturonases Gene RiPG2 Accelerates Fruit Softening in Solanum lycopersicum

by Tiemei Li, Xiao Guo, Yuxiao Chen, Jing Li, Caihong Yu, Zhifeng Guo and Guohui Yang

Agronomy 2024, 14(1), 160; https://doi.org/10.3390/agronomy14010160 - 10 Jan 2024

Cited by 6 | Viewed by 2029

Abstract

The high susceptibility of raspberries to softening restricts the development of the raspberry industry. The primary causes of fruit softening are the breakdown of components linked to the cell wall and the destruction of the cell wall structure itself. Polygalacturonase (PG), a key [...] Read more.

The high susceptibility of raspberries to softening restricts the development of the raspberry industry. The primary causes of fruit softening are the breakdown of components linked to the cell wall and the destruction of the cell wall structure itself. Polygalacturonase (PG), a key enzyme that catalyzes pectin degradation, plays a critical role in fruit softening. However, there are currently limited studies on the mechanism of PG genes in raspberry fruit softening. In this study, a PG gene, RiPG2, was isolated from raspberry (Rubus idaeus L.). ‘Polka’ fruits and tomato plants overexpressing RiPG2 were obtained by Agrobacterium tumefaciens-mediated leaf disc transformation to elucidate the role of RiPG2 in fruit softening. The total length of the RiPG2 gene is 1185 bp, and the gene encodes a total of 394 amino acids. The GFP fusion protein was expressed at the chloroplast under laser confocal microscopy, indicating that the RiPG2 protein is localized to the chloroplasts. Phenotypic analysis revealed that the fruit firmness of three strains was considerably less than that of controls, but PG enzyme activity was increased. Overexpression of RiPG2 altered the content of cell wall components, with an increase in water-soluble pectin (WSP) and ion-bound pectin (ISP) but a decrease in protopectin, cellulose, hemicellulose, and covalently bound pectin (CSP). In addition, RiPG2 positively regulated the expression of cell wall metabolism-related genes such as SlEXP1, SlTBG4, SlXTH5, and SlPL. These results suggest that the RiPG2 gene regulates the structure and composition of the cell wall and acts synergistically with other cell wall metabolism-related genes to promote fruit softening. This study provides a new candidate gene for molecular breeding to improve raspberry firmness. Full article

(This article belongs to the Section Horticultural and Floricultural Crops)

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12 pages, 8162 KiB

Open AccessEditor’s ChoiceArticle

Identification of Clubroot-Resistant Germplasm in a Radish (Raphanus sativus L.) Core Collection

by Yang Ma, Haiping Wang, Jiangping Song, Wenlong Yang, Huixia Jia, Niels Agerbirk, Yinan Chen, Chen Li, Yinglan Piao, Sen Li and Xiaohui Zhang

Agronomy 2024, 14(1), 157; https://doi.org/10.3390/agronomy14010157 - 10 Jan 2024

Cited by 2 | Viewed by 1716

Abstract

Clubroot disease, caused by Plasmodiophora brassicae, poses a significant global threat to cruciferous crops. The epidemic area of clubroot disease is expanding rapidly. In response to this pressing issue, there is a compelling need for the development of clubroot disease-resistant radish cultivars. [...] Read more.

Clubroot disease, caused by Plasmodiophora brassicae, poses a significant global threat to cruciferous crops. The epidemic area of clubroot disease is expanding rapidly. In response to this pressing issue, there is a compelling need for the development of clubroot disease-resistant radish cultivars. China boasts an extensive array of radish varieties and germplasm resources. However, a comprehensive assessment of their resistance to clubroot has not yet been carried out, thereby impeding the effective utilization of germplasm and clubroot-resistant breeding. Therefore, it is urgent to systematically evaluate the clubroot resistance of the radish germplasm and identify resistant resources. In this study, clubroot resistance evaluations were conducted on 268 excellent radish varieties derived from 30 provinces in China, as well as seven accessions from Russia, North Korea, France, South Korea, and Germany. The resistance evaluation revealed a diverse range of resistance indices, with a mean disease index (DI) ranging from 0.6 to 58.5, showing significant disparities in clubroot resistance among these radish resources. A total of six accessions were characterized as highly resistant to clubroot, and a further 50 accessions were characterized as resistant. The disease-resistant radishes showed diversity in horticultural traits. Provinces in South China contributed significantly more resistance germplasm than those of North China. These materials are of great value for both genetic investigation and the crop breeding of clubroot resistance. Furthermore, we employed a previously established clubroot-resistance-linked SSR marker to analyze the clubroot-resistant resources. The accessions exhibited dissimilar genetic profiles from known clubroot-resistant germplasm, suggesting their potential status as novel sources of clubroot resistance. Conclusively, these newly identified accessions enriched the genetic diversity within the clubroot-resistant gene pool and may contribute to the future cloning of previously undiscovered clubroot-resistant genes. Full article

(This article belongs to the Special Issue Balancing Plant Robustness to Stress and Product Quality in Crops—Breeding Perspectives and Fundamental Studies)

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14 pages, 3644 KiB

Open AccessEditor’s ChoiceArticle

Environmental Impact Assessment of Rice–Wheat Rotation Considering Annual Nitrogen Application Rate

by Yulin Yang, Xiaohu Liu, Yinglong Chen, Qiang Xu, Qigen Dai, Huanhe Wei, Ke Xu and Hongcheng Zhang

Agronomy 2024, 14(1), 151; https://doi.org/10.3390/agronomy14010151 - 9 Jan 2024

Cited by 1 | Viewed by 2046

Abstract

Rice–wheat rotation is a widely adopted multiple-cropping system in the Yangtze River Basin, China. Nitrogen (N) fertilizer is a key factor in regulating crop yield; however, only a few studies have considered the impact of annual N application on the yield, environmental impacts, [...] Read more.

Rice–wheat rotation is a widely adopted multiple-cropping system in the Yangtze River Basin, China. Nitrogen (N) fertilizer is a key factor in regulating crop yield; however, only a few studies have considered the impact of annual N application on the yield, environmental impacts, and economic profits of rice–wheat rotation systems. In this study, a field experiment was conducted in the Jiangsu Province from 2020 to 2022. The rice and wheat seasons included six and five N fertilizer application rates, respectively (Rice: 0, 180, 240, 300, 360, and 420 kg N ha⁻¹; Wheat: 0, 180, 240, 300, and 360 kg N ha⁻¹), combined to form a total of 30 treatments. Life-cycle assessment was used to evaluate the environmental impacts of rice–wheat rotation under different N application treatments, using area, yield, and economic profit as functional units. Ten environmental impact categories were selected, including global warming. The results showed that grain yield did not consistently increase with an increase in N application, and the annual yield was the highest when 300 and 240 kg N ha⁻¹ (R300W240 treatment) was applied in the rice and wheat seasons, respectively. The area-based weighting index of the R300W240 treatment ranked 20th among the 30 treatments, while the yield- and profit-based weighting indices were the lowest among the 30 treatments, decreasing by 14.9% and 28.7%, respectively, compared to the other treatments. The R300W240 treatment was the optimal annual N application strategy for rice–wheat rotation. Among the 10 environmental impacts considered, urea production contributed significantly to over eight environmental impacts, whereas the pollutant losses caused by its application contributed significantly to six environmental impacts. These findings reveal the dependence of the rice–wheat rotation system on the unsustainable use of N fertilizer and indicate that N fertilizer management practices should be further optimized to improve the environmental sustainability of grain production in the future. Full article

(This article belongs to the Special Issue Adaptation of Crops to the Environment under Climate Change: Physiological and Agronomic Strategies — Volume II)

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14 pages, 9050 KiB

Open AccessEditor’s ChoiceArticle

Combined Effect of Freeze–Thaw Cycles and Biochar Addition on Soil Nitrogen Leaching Characteristics in Seasonally Frozen Farmland in Northeast China

by Lihong Wang, Tianxiao Li, Hui Liu, Zuowei Zhang, Aizheng Yang and Hongyu Li

Agronomy 2024, 14(1), 153; https://doi.org/10.3390/agronomy14010153 - 9 Jan 2024

Cited by 4 | Viewed by 2188

Abstract

Global climate warming and increased climate variability may increase the number of annual freeze–thaw cycles (FTCs) in temperate zones. The occurrence of more frequent FTCs is predicted to influence soil carbon and nitrogen cycles and increase nitrogen leaching. Biochar has the potential to [...] Read more.

Global climate warming and increased climate variability may increase the number of annual freeze–thaw cycles (FTCs) in temperate zones. The occurrence of more frequent FTCs is predicted to influence soil carbon and nitrogen cycles and increase nitrogen leaching. Biochar has the potential to increase soil organic carbon storage and decrease nitrogen leaching. This study aims to investigate the impact of freeze–thaw cycles (FTCs) on soil nitrogen leaching in temperate zones, considering the potential exacerbation of FTCs due to global climate warming and increased climate variability. This study focuses on how biochar, a carbon-rich material produced from biomass, might mitigate nitrogen leaching by influencing soil characteristics. This study explores the interactions between different laboratory-simulated FTC frequencies (ranging from 0 to 12 cycles) and various biochar addition ratios (0%, 2%, 4%, and 6% w/w) on soil nitrogen leaching based on a total of 60 soil columns. Pearson correlations between the soil quality indicators and nitrogen leaching characteristics were detected, and partial least squares path modeling (PLS-PM) was used to assess the effects of the FTCs, biochar addition ratios, and soil quality indicators on the nitrogen leaching content. The results showed that the amount of leached soil NH₄⁺-N and NO₃⁻-N reached 0.129–1.726 mg and 2.90–7.90 mg, respectively. NH₄⁺-N and NO₃⁻-N first increased and then decreased under the FTCs, with the highest values being observed after the 6th FTC. As the biochar addition ratio increased, the NH₄⁺-N and NO₃⁻-N contents decreased. Correlation analysis showed that the nitrogen leaching content was significantly related to the soil pH, soil organic matter (SOM), NH₄⁺-N content, and microbial biomass carbon content (MBC) (p < 0.01). The results of the conceptual path model revealed that nitrogen leaching characteristics were significantly affected by the pH, SOM, soil nitrogen content, and biochar addition ratio. Our results suggest that biochar addition can help reduce nitrogen leaching in farmland soil in areas with black soil and seasonal freeze–thaw cycles. Full article

(This article belongs to the Section Agricultural Biosystem and Biological Engineering)

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18 pages, 4086 KiB

Open AccessEditor’s ChoiceArticle

Estimation of Plant Height and Biomass of Rice Using Unmanned Aerial Vehicle

by Enze Song, Guangcheng Shao, Xueying Zhu, Wei Zhang, Yan Dai and Jia Lu

Agronomy 2024, 14(1), 145; https://doi.org/10.3390/agronomy14010145 - 8 Jan 2024

Cited by 6 | Viewed by 2852

Abstract

Plant height and biomass are important indicators of rice yield. Here we combined measured plant physiological traits with a crop growth model driven by unmanned aerial vehicle spectral data to quantify the changes in rice plant height and biomass under different irrigation and [...] Read more.

Plant height and biomass are important indicators of rice yield. Here we combined measured plant physiological traits with a crop growth model driven by unmanned aerial vehicle spectral data to quantify the changes in rice plant height and biomass under different irrigation and fertilizer treatments. The study included two treatments: I—water availability factor (i.e., three drought objects, optimal, and excess water); and II—two levels of deep percolation and five nitrogen fertilization doses. The introduced model is extreme learning machine (ELM), back propagation neural network (BPNN), and particle swarm optimization-ELM (PSO-ELM), respectively. The results showed that: (1) Proper water level regulation (3~5 cm) significantly increased the accumulation of spike biomass, which was about 6% higher compared to that under flooded conditions. (2) For plant height inversion, the ELM model was optimal with a mean coefficient of determination of 0.78, a mean root mean square error of 0.26 cm, and a mean performance deviation rate of 2.08. For biomass inversion, the PSO-ELM model was optimal with a mean coefficient of determination of 0.88, a mean root mean square error of 3.8 g, and a mean performance deviation rate of 3.29. This study provided the possible opportunity for large-scale estimations of rice yield under environmental disturbances. Full article

(This article belongs to the Special Issue Applications of Machine Learning and Remote Sensing in Crop and Vegetation Monitoring)

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11 pages, 588 KiB

Open AccessEditor’s ChoiceArticle

Swine Wastewater Treatment System Using Constructed Wetlands Connected in Series

by Amalia García-Valero, José Alberto Acosta, Ángel Faz, María Dolores Gómez-López, Dora María Carmona, Martire Angélica Terrero, Oumaima El Bied and Silvia Martínez-Martínez

Agronomy 2024, 14(1), 143; https://doi.org/10.3390/agronomy14010143 - 7 Jan 2024

Cited by 4 | Viewed by 1951

Abstract

The main objective of this study was to analyze the efficiency of CWs for purifying swine wastewater in order to reduce its pollutant load. The system included a pretreatment module (raw swine wastewater tank, phase separator, and settlement tank), and three constructed wetlands [...] Read more.

The main objective of this study was to analyze the efficiency of CWs for purifying swine wastewater in order to reduce its pollutant load. The system included a pretreatment module (raw swine wastewater tank, phase separator, and settlement tank), and three constructed wetlands connected in series and planted with Phragmites australis and Suaeda vera. Three treatment cycles were carried out with a total hydraulic retention time in the wetland of 21 days for each cycle. Pig slurry samples were collected in triplicate after each treatment module, and physical–chemical analyses were performed. The results showed that the phase separator decreased the suspended solids, turbidity, and the chemical oxygen demand in the treated swine wastewater. The system enabled considerable nitrogen reductions (Kjeldahl nitrogen, NH₄⁺, and organic nitrogen), and the highest removal was reported in the wetlands. However, the cations and anions showed different efficiencies. In some cases (Ca, Mg, and Na), the final concentrations were increased, which could be explained by their release from the substrate; however, there were no statistical differences among the CW effluents and the raw pig slurry. Therefore, the integral pig slurry treatment system with constructed wetlands increased the quality of the treated swine wastewater and thus can be used for its sustainable agronomic valorization. This thereby enables savings in inorganic fertilizers and irrigation water. Full article

(This article belongs to the Special Issue Sustainable Agri-Tech Engineering: Building Resilience for Climate Change Adaptation)

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21 pages, 5128 KiB

Open AccessEditor’s ChoiceArticle

Inverting Chlorophyll Content in Jujube Leaves Using a Back-Propagation Neural Network–Random Forest–Ridge Regression Algorithm with Combined Hyperspectral Data and Image Color Channels

by Jingming Wu, Tiecheng Bai and Xu Li

Agronomy 2024, 14(1), 140; https://doi.org/10.3390/agronomy14010140 - 5 Jan 2024

Cited by 7 | Viewed by 1944

Abstract

Chlorophyll content is highly susceptible to environmental changes, and monitoring these changes can be a crucial tool for optimizing crop management and providing a foundation for research in plant physiology and ecology. This is expected to deepen our scientific understanding of plant ecological [...] Read more.

Chlorophyll content is highly susceptible to environmental changes, and monitoring these changes can be a crucial tool for optimizing crop management and providing a foundation for research in plant physiology and ecology. This is expected to deepen our scientific understanding of plant ecological adaptation mechanisms, offer a basis for improving agricultural production, and contribute to ecosystem management. This study involved the collection of hyperspectral data, image data, and SPAD data from jujube leaves. These data were then processed using SG smoothing and the isolated forest algorithm, following which eigenvalues were extracted using a combination of Pearson’s phase relationship method and the Partial Least Squares Regression–continuous projection method. Subsequently, seven methods were employed to analyze the results, with hyperspectral data and color channel data used as independent variables in separate experiments. The findings indicated that the integrated BPNN-RF-Ridge Regression algorithm provided the best results, with an R² of 0.8249, MAE of 2.437, and RMSE of 2.9724. The inclusion of color channel data as an independent variable led to a 3.2% improvement in R², with MAE and RMSE increasing by 1.6% and 3.9%, respectively. These results demonstrate the effectiveness of integrated methods for the determination of chlorophyll content in jujube leaves and underscore the potential of using multi-source data to improve the model fit with a minimal impact on errors. Further research is warranted to explore the application of these findings in precision agriculture for jujube yield optimization and income-related endeavors, as well as to provide insights for similar studies in other plant species. Full article

(This article belongs to the Section Precision and Digital Agriculture)

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23 pages, 1592 KiB

Open AccessEditor’s ChoiceReview

Microbiota Ecosystem Services in Vineyards and Wine: A Review

by Isabel García-Izquierdo, Victor J. Colino-Rabanal, Mercedes Tamame and Fernando Rodríguez-López

Agronomy 2024, 14(1), 131; https://doi.org/10.3390/agronomy14010131 - 4 Jan 2024

Cited by 9 | Viewed by 3646

Abstract

The domestication of vines started in Asia 11,000 years ago, although it was not until the 19th century that oenology was established as a scientific discipline thanks to the research of Louis Pasteur on the role of microorganisms in wine fermentation. At the [...] Read more.

The domestication of vines started in Asia 11,000 years ago, although it was not until the 19th century that oenology was established as a scientific discipline thanks to the research of Louis Pasteur on the role of microorganisms in wine fermentation. At the present time, the progression in next-generation sequencing (NGS) technologies is helping to facilitate the identification of microbial dynamics during winemaking. These advancements have aided winemakers in gaining a more comprehensive understanding of the role of microbiota in the fermentation process, which, in turn, is ultimately responsible for the delivery of provisioning (wine features and its production), regulating (such as carbon storage by vineyards, regulation of soil quality, and biocontrol of pests and diseases) or cultural (such as aesthetic values of vineyard landscapes, scholarly enjoyment of wine, and a sense of belonging in wine-growing regions) ecosystem services. To our knowledge, this is the first review of the state of knowledge on the role of microbiota in the delivery of ecosystem services in the wine sector, as well as the possibility of valuing them in monetary terms by operating logic chains, such as those suggested by the SEEA-EA framework. This paper concludes with a review of management practices that may enhance the value of microbiota ecosystem services and the role of smart farming in this task. Full article

(This article belongs to the Special Issue Viticulture Economic and Ecological Benefit)

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15 pages, 8507 KiB

Open AccessEditor’s ChoiceArticle

Dependence of the Pea Grain Yield on Climatic Factors under Semi-Arid Conditions

by Vasiliy Gudko, Alexander Usatov, Tatiana Minkina, Nadezhda Duplii, Kirill Azarin, Tatiana V. Tatarinova, Svetlana Sushkova, Ankit Garg and Yuri Denisenko

Agronomy 2024, 14(1), 133; https://doi.org/10.3390/agronomy14010133 - 4 Jan 2024

Cited by 5 | Viewed by 1974

Abstract

Field peas are one of the most common crops and are grown in various climatic zones. However, the productivity of this crop can be largely limited by climatic factors. This study investigated the influence of climatic factors on pea grain yield in the [...] Read more.

Field peas are one of the most common crops and are grown in various climatic zones. However, the productivity of this crop can be largely limited by climatic factors. This study investigated the influence of climatic factors on pea grain yield in the semi-arid conditions of the Rostov region of Russia in 2008–2020. To quantify climatic factors, agro-climatic variables were used, such as total temperatures below the minimum temperature, the number of days with temperatures below the minimum temperature, total temperatures above the critical temperature, the number of days with temperatures above the critical temperature, and the Selyaninov hydrothermal coefficient. Agro-climatic variables were calculated using daily climatic variables, such as maximum and minimum temperatures, relative air humidity, and precipitation during pea growing season (April–June). The yield of the pea varied from 90 to 250 kg/ha. In general, the productivity of peas is negatively affected by high temperatures and low humidification level. The yield is negatively correlated with accumulative temperatures above the critical temperature and the number of days with temperatures above the critical temperature and positively correlated with the Selyaninov hydrothermal coefficient and the precipitation in all analyzed areas. The influence of the accumulative temperatures above the critical temperature is the most significant. It explains between 6.6% and 78.9% of the interannual variability of the pea yield. The increase in accumulative temperatures above the critical threshold by every 1 °C will contribute to a decrease in pea grain yield by an average of 0.150 kg/ha. The maximum temperatures in May and June (the period of flowering–grain filling) have the most negative impact on the yield. A 1 °C increase in the average maximum temperature during this period will contribute to a decrease in pea yield by an average of 19.175 kg/ha. The influence of total precipitation during the growing season explains between 12.3% and 50.0% of the variability. The 1 mm decrease in the total precipitation for the growing season will lead to a decrease in pea yields by an average of 0.736 kg/ha. The results of this study can be applied to regional yield forecasting, as well as predicting the impact of climate variability on the grain yield of pea crops in arid areas. Full article

(This article belongs to the Special Issue Improving Functioning of Soil–Plant Systems Using the Application of Sustainable and Intelligent Methods—2nd Edition)

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17 pages, 3591 KiB

Open AccessEditor’s ChoiceArticle

Soil Microorganisms Mediated the Responses of the Plant–Soil Systems of Neotrinia splendens to Nitrogen Addition and Warming in a Desert Ecosystem

by Zhuxin Mao, Ming Yue, Yuchao Wang, Lijuan Li and Yang Li

Agronomy 2024, 14(1), 132; https://doi.org/10.3390/agronomy14010132 - 4 Jan 2024

Cited by 4 | Viewed by 1717

Abstract

Covering about 30% of the global total land area, desert ecosystems have been influenced by warming and nitrogen deposition. However, it remains unclear how desert ecosystems respond to warming and nitrogen deposition. Therefore, we conducted a greenhouse experiment to examine the impacts of [...] Read more.

Covering about 30% of the global total land area, desert ecosystems have been influenced by warming and nitrogen deposition. However, it remains unclear how desert ecosystems respond to warming and nitrogen deposition. Therefore, we conducted a greenhouse experiment to examine the impacts of N addition and warming on the plant–soil system of Neotrinia splendens, the dominant plant in the desert ecosystem in Northern China. Our findings revealed that low-N dose (N₁) and high-N dose additions (N₂) increased the biomass by 22.83% and 54.23%, respectively; meanwhile, moderate warming (T₂) and severe warming (T₃) decreased the biomass by 39.07% and 45.47%, respectively. N addition did not significantly affect the C:N:P stoichiometry in the plant–soil system. T₂ and T₃ decreased the leaf N content by 17.50% and 16.20%, respectively, and decreased the leaf P content by 10.61% and 45.29%, respectively. This resulted in the plant C:N ratio, C:P ratio, and N:P ratio increasing with warming. Furthermore, warming or N addition not only decreased soil microbial diversity, but also inhibited microbial genera associated with nutrient cycling, such as that of Tumebacillus spp., Bacillus spp., and Mortierella spp.; it additionally influenced important bacterial functions, such as nitrate reduction and ureolysis. Moreover, warming and N addition induced P limitation in the plant–soil system by inhibiting soil microorganisms, such as Mortierella spp. and Bacillus spp., which are associated with P transformation; this was also brought about by increasing the effects of leaf P content on leaf N:P. In conclusion, our results showed that warming and N addition had significant effects on the C:N:P stoichiometry of the plant–soil system through microbial mediation and led to P limitation in the system, regardless of how they affected biomass. Soil microorganisms could mediate the impacts of environmental changes on the plant–soil system. Our findings may provide valuable insights for adjusting vegetation restoration strategies in desert ecosystems under environmental changes. Full article

(This article belongs to the Special Issue The Response of Grassland Ecosystem to Nutrient Additions)

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21 pages, 9661 KiB

Open AccessEditor’s ChoiceArticle

Early Mapping Method for Different Planting Types of Rice Based on Planet and Sentinel-2 Satellite Images

by Yunfei Yu, Linghua Meng, Chong Luo, Beisong Qi, Xinle Zhang and Huanjun Liu

Agronomy 2024, 14(1), 137; https://doi.org/10.3390/agronomy14010137 - 4 Jan 2024

Cited by 5 | Viewed by 2249

Abstract

In Northeast China, transplanted rice cultivation has been adopted to extend the rice growing season and boost yields, responding to the limitations of the cumulative temperature zone and high food demand. However, direct-seeded rice offers advantages in water conservation and labour efficiency. The [...] Read more.

In Northeast China, transplanted rice cultivation has been adopted to extend the rice growing season and boost yields, responding to the limitations of the cumulative temperature zone and high food demand. However, direct-seeded rice offers advantages in water conservation and labour efficiency. The precise and timely monitoring of the distribution of different rice planting types is key to ensuring food security and promoting sustainable regional development. This study explores the feasibility of mapping various rice planting types using only early-stage satellite data from the rice growing season. We focused on Daxing Farm in Fujin City, Jiamusi City, Heilongjiang Province, for cropland plot extraction using Planet satellite imagery. Utilizing Sentinel-2 satellite imagery, we analysed the differences in rice’s modified normalized difference water index (MNDWI) during specific phenological periods. A multitemporal Gaussian mixture model (GMM) was developed, integrated with the maximum expectation algorithm, to produce binarized classification outcomes. These results were employed to detect surface changes and map the corresponding rice cultivation types. The probability of various rice cultivation types within arable plots was quantified, yielding a plot-level rice-cultivation-type mapping product. The mapping achieved an overall accuracy of 91.46% in classifying rice planting types, with a Kappa coefficient of 0.89. The area extraction based on arable land parcels showed a higher R² by 0.1109 compared to pixel-based area extraction and a lower RMSE by 0.468, indicating more accurate results aligned with real statistics and surveys, thus validating our study’s method. This approach, not requiring labelled samples or many predefined parameters, offers a new method for rapid and feasible mapping, especially suitable for direct-seeded rice areas in Northeast China. It fills the gap in mapping rice distribution for different planting types, supporting water management in rice fields and policies for planting-method changes. Full article

(This article belongs to the Special Issue Application of Remote Sensing and GIS Technology in Agriculture)

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21 pages, 13478 KiB

Open AccessEditor’s ChoiceArticle

Comparative Study on the Effects of Different Soil Improvement Methods in Blueberry Soil

by Yanan Li, Shuxia Liu, Dongmei Wang, Qi Li, Chengyu Wang and Lin Wu

Agronomy 2024, 14(1), 125; https://doi.org/10.3390/agronomy14010125 - 3 Jan 2024

Cited by 3 | Viewed by 2431

Abstract

Soil improvement methods can result in changes in the microbial community in blueberry soil. Bacterial communities play an important role in soil fertilizer and plant nutrient acquisition. In this study, the response of microbial community composition, microbial function, and the nitrogen (N) cycle [...] Read more.

Soil improvement methods can result in changes in the microbial community in blueberry soil. Bacterial communities play an important role in soil fertilizer and plant nutrient acquisition. In this study, the response of microbial community composition, microbial function, and the nitrogen (N) cycle to different improvement methods was analyzed using high-throughput sequencing to investigate the best soil improvement method from a microbial perspective. The results showed that the highest microbial diversity was observed in the treatment involving peat combined with mushroom bran (T2), followed by the peat combined with acidified rice husk (T2) both in the rhizosphere and roots. The dominant phyla were Proteobacteria and Actinobacteria both in the blueberry rhizosphere soil and roots. Interestingly, Acidobacterium and Paludibaculum, belonging to the Acidobacteria phylum, exhibited the most significant influence and were most predominant in the T2 treatment rhizosphere soil. The T2 treatment promoted the growth of N fixation functional bacteria both in the rhizosphere soil and roots. At the module level, the T2 treatment enhanced N fixation and suppressed the assimilatory and dissimilatory nitrate reduction reactions, denitrification, and nitrification in the blueberry rhizosphere. Additionally, the T2 treatment increased the abundance of root endophytic microbes involved in N fixation. Overall, our findings suggest that the addition of peat combined with acidified rice husk is the optimal soil improvement method for blueberry cultivation. Full article

(This article belongs to the Section Horticultural and Floricultural Crops)

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14 pages, 2980 KiB

Open AccessEditor’s ChoiceArticle

Phytoremediation of Toxic Lead from Contaminated Soil Using Neyraudia reynaudiana: Soil of Xuzhou as a Case Study

by Fuyao Chen, Shaoliang Zhang, Zanxu Chen, Yuanyuan Zhang and Bo Cao

Agronomy 2024, 14(1), 118; https://doi.org/10.3390/agronomy14010118 - 2 Jan 2024

Cited by 2 | Viewed by 2551

Abstract

Lead (Pb), as one of the main pollution elements, has resulted in large-scale soil pollution around the world. Even if phytoremediation can solve this problem, the selection of restoration potential plants has always been a scientific problem. As a multifunctional repair plant, Neyraudia [...] Read more.

Lead (Pb), as one of the main pollution elements, has resulted in large-scale soil pollution around the world. Even if phytoremediation can solve this problem, the selection of restoration potential plants has always been a scientific problem. As a multifunctional repair plant, Neyraudia reynaudiana can rehabilitate both polluted soils and slopes. N. reynaudiana has been widely used in terrain restoration in southern China before. This study was the first to study the growth and Pb absorption and enrichment capacity of N. reynaudiana in Xuzhou, north of the Yangtze River. In this study, N. reynaudiana was planted in soils with different lead concentrations, and the change of lead content in roots, shoots, and soils, as well as the redox enzyme, was tested and analyzed during each growth stage. The results showed that the roots could absorb Pb and transfer 79.45% to the shoots at most. With the growth of the plant, the ability to accumulate and transfer gradually increased. Moreover, when the soil Pb concentration was above 800 mg kg⁻¹, the ability to accumulate by N. reynaudiana was significantly restrained. Furthermore, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) first acted on the redox response in the initial phase, while increasing the pollutant concentration or the growth of N. reynaudiana in the later stage, and the glutathione reductase (GR) redox system continued to feed back on the lead stress. This study proved that N. reynaudiana is a kind remediation plant for lead pollution soil and could repair soil with a lead pollution concentration lower than 800 mg kg⁻¹. The results provide a theoretical reference for clarifying the action mechanism and threshold value of N. reynaudiana in rehabilitating soil lead pollution and provide practical guidance for the planting proportion of N. reynaudiana. Full article

(This article belongs to the Special Issue Heavy Metal Tolerance Mechanism of Plants and Improvement in Contaminated Soil)

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22 pages, 4032 KiB

Open AccessEditor’s ChoiceArticle

Effect of Fertigation with Struvite and Ammonium Nitrate on Substrate Microbiota and N₂O Emissions in a Tomato Crop on Soilless Culture System

by Mar Carreras-Sempere, Miriam Guivernau, Rafaela Caceres, Carmen Biel, Joan Noguerol and Marc Viñas

Agronomy 2024, 14(1), 119; https://doi.org/10.3390/agronomy14010119 - 2 Jan 2024

Cited by 4 | Viewed by 1833

Abstract

Struvite and ammonium nitrate (AN), as wastewater-recovered products, are possible alternatives as raw materials for nutrient solutions. However, their impact on the rhizosphere microbiota and N₂O emissions is scarcely known. Therefore, the present research studies the ecological changes in the bulk-substrate [...] Read more.

Struvite and ammonium nitrate (AN), as wastewater-recovered products, are possible alternatives as raw materials for nutrient solutions. However, their impact on the rhizosphere microbiota and N₂O emissions is scarcely known. Therefore, the present research studies the ecological changes in the bulk-substrate microbiome and its correlation with N₂O emissions in a perlite-based system tomato crop under (i) conventional synthetic fertigation management; (ii) fertigation with struvite; and (iii) struvite and AN. A high bacterial diversity and the natural presence of plant-growth-promoting rhizobacteria in a soilless system are highlighted. However, the different N-NH₄⁺:N-NO₃⁻ ratios influence the ecological niches of ammonia-oxidizing archaea (AOA) and bacteria (AOB), with a stronger response by AOB community, while AOA kept constant regarding the fertilization applied. Despite this, enrichment of N-transforming bacterial phylotypes was relatively enhanced (mainly Nitrosomonas, Nitrosospira, and Nitrospira) concomitant with the production of N₂O emissions when ammonium fertilization was overapplied. In the absence of a plant, N₂O emissions were positively correlated, respectively, with Nitrosospira and AOB:AOA ratio, suggesting potential indicators for ammonium availability in the substrate. Fertilizer blends using recovered nutrients are a feasible alternative for increasing circularity in horticulture. Nevertheless, optimum fertilizer management is needed due to its influence on rhizosphere microbiota and N₂O emissions. Full article

(This article belongs to the Section Farming Sustainability)

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24 pages, 9222 KiB

Open AccessEditor’s ChoiceArticle

Potted Phalaenopsis Grading: Precise Bloom and Bud Counting with the PA-YOLO Algorithm and Multiviewpoint Imaging

by Yi Yang, Guankang Zhang, Shutao Ma, Zaihua Wang, Houcheng Liu and Song Gu

Agronomy 2024, 14(1), 115; https://doi.org/10.3390/agronomy14010115 - 2 Jan 2024

Cited by 5 | Viewed by 1799

Abstract

The accurate detection and counting of flowers ensure the grading quality of the ornamental plants. In automated potted flower grading scenarios, low detection precision, occlusions and overlaps impact counting accuracy. This study proposed a counting method combining a deep learning algorithm with multiple [...] Read more.

The accurate detection and counting of flowers ensure the grading quality of the ornamental plants. In automated potted flower grading scenarios, low detection precision, occlusions and overlaps impact counting accuracy. This study proposed a counting method combining a deep learning algorithm with multiple viewpoints. Firstly, a flower detection model, PA-YOLO, was developed based on YOLOv5 by designing a two-scale detection branch, optimizing the number of bottlenecks and integrating a dynamic head framework. Next, PA-YOLO was used to detect grouped 360-viewpoint images of each potted plant to determine the optimal number of viewpoints for counting. The detection results indicated that PA-YOLO achieved a mean average precision (mAP) of 95.4% and an average precision (AP) of 91.9% for occluded blooms on our Phalaenopsis flower dataset. For the optimal number of viewpoints, the average counting accuracy of buds and blooms was highest at three viewpoints, with scores of 96.25% and 93.33%, respectively. The final counting accuracy reached 95.56% in flower counting tests conducted from three viewpoints. The overall results suggest that the proposed method can effectively detect and count flowers in complex occlusion and overlap environments, providing guidance for designing and implementing the vision component in an automated potted flower grading system. Full article

(This article belongs to the Section Precision and Digital Agriculture)

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17 pages, 3353 KiB

Open AccessEditor’s ChoiceArticle

Water–Salt Migration Patterns among Cropland–Wasteland–Fishponds in the River-Loop Irrigation Area

by Cuicui Yu, Haibin Shi, Qingfeng Miao, José Manuel Gonçalves, Yan Yan, Zhiyuan Hu, Cong Hou and Yi Zhao

Agronomy 2024, 14(1), 107; https://doi.org/10.3390/agronomy14010107 - 1 Jan 2024

Cited by 3 | Viewed by 1921

Abstract

In order to investigate the influence of freshwater fish ponds on water and salt transport in cultivated wasteland in salinized areas, a typical study area was selected in the middle and lower reaches of the Hetao Irrigation District in China in the Yichang [...] Read more.

In order to investigate the influence of freshwater fish ponds on water and salt transport in cultivated wasteland in salinized areas, a typical study area was selected in the middle and lower reaches of the Hetao Irrigation District in China in the Yichang Irrigation Domain, and the temporal and spatial changes in the salinity of soil and salinity of groundwater and fish pond water in the cultivated–wasteland–fish pond system were characterized through the monitoring of the environmental information of soil and groundwater at the boundaries of the cultivated land, wasteland, and fish ponds. Salinity changes and groundwater migration in different periods were determined, and the response of soil salinity to the depth of groundwater burial was analyzed, as well as the effect of fish ponds on soil salinization. The results showed that the amount of groundwater migrating from cropland to wasteland during the simulation period in 2022 was 2700 m³, the amount of groundwater migrating from wasteland to fish ponds was 630 m³, and the amount of groundwater migrating from fish ponds to wasteland during the fall watering period was 440 m³. From an overall perspective, the average soil salinity of wasteland was 1.56 times higher than that of the boundary of fish ponds. Not only do fish ponds play a positive role in the ecosystem, but they also have a desalinization effect that reduces soil salinity significantly. Groundwater depth and soil salinity have an exponential relationship; when the depth of groundwater is greater than 1.75 m, the soil salinity varies little with the depth of groundwater and the soil salinity is less than 0.66 ds/m, which can be determined as the critical depth, and the average depth of groundwater in cultivated land in the study area is 1.5 m. Therefore, it is necessary to reasonably control the water level of fish ponds, so as to make the groundwater depth of cultivated land control between 1.75 m and 2.0 m, and to prevent soil salinization. Full article

(This article belongs to the Special Issue Water Saving in Irrigated Agriculture)

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14 pages, 3265 KiB

Open AccessEditor’s ChoiceArticle

Time Series from Sentinel-2 for Organic Durum Wheat Yield Prediction Using Functional Data Analysis and Deep Learning

by Adriano Mancini, Francesco Solfanelli, Luca Coviello, Francesco Maria Martini, Serena Mandolesi and Raffaele Zanoli

Agronomy 2024, 14(1), 109; https://doi.org/10.3390/agronomy14010109 - 1 Jan 2024

Cited by 7 | Viewed by 2277

Abstract

Yield prediction is a crucial activity in scheduling agronomic operations and in informing the management and financial decisions of a wide range of stakeholders of the organic durum wheat supply chain. This research aims to develop a yield forecasting system by combining vegetation [...] Read more.

Yield prediction is a crucial activity in scheduling agronomic operations and in informing the management and financial decisions of a wide range of stakeholders of the organic durum wheat supply chain. This research aims to develop a yield forecasting system by combining vegetation index time-series data from Sentinel-2 L2A time-series data, field-measured yields, and deep learning techniques. Remotely sensed data over a season could be, in general, noisy and characterized by a variable density due to weather conditions. This problem was mitigated using Functional Principal Component Analysis (FPCA). We obtained a functional representation of acquired data, and starting from this, we tried to apply deep learning to predict the crop yield. We used a Convolutional Neural Network (CNN) approach, starting from images that embed temporal and spectral dimensions. This representation does not require one to a priori select a vegetation index that, typically, is task-dependent. The results have been also compared with classical approaches as Partial Least Squares (PLS) on the main reference vegetation indexes such as the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Red Edge index (NDRE), considering both in-season and end-season scenarios. The obtained results show that the image-based representation of multi-spectral time series could be an effective method to estimate the yield, also, in the middle stage of cropping with R² values greater than 0.83. The developed model could be used to estimate yield the neighbor fields characterized by similar setups in terms of the crop, variety, soil, and, of course, management. Full article

(This article belongs to the Special Issue Predictions and Estimations in Agricultural Production under a Changing Climate—Volume II)

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15 pages, 1750 KiB

Open AccessEditor’s ChoiceArticle

Understanding the Potential to Increase Adoption of Orphan Crops: The Case of Lathyrus spp. Cultivation in Greece

by Maria Goufa, Evaggelos Makeroufas, Maria Gerakari, Efi Sarri, Athanasios Ragkos, Penelope J. Bebeli, Alma Balestrazzi and Eleni Tani

Agronomy 2024, 14(1), 108; https://doi.org/10.3390/agronomy14010108 - 1 Jan 2024

Cited by 6 | Viewed by 3071

Abstract

Little progress has been made in translating the increased awareness of neglected and underutilized crops into a viable tool for advancing not just sustainable development in rural areas but also sustainable agricultural and secured food systems. This is caused, in part, by a [...] Read more.

Little progress has been made in translating the increased awareness of neglected and underutilized crops into a viable tool for advancing not just sustainable development in rural areas but also sustainable agricultural and secured food systems. This is caused, in part, by a lack of understanding the importance of several underutilized crops that are currently in cultivation. Among underutilized crops, grasspea (Lathyrus sativus) is an orphan legume crop with great agronomic potential due to its suitability for a variety of sustainable food and feed production systems throughout the world’s semi-arid and arid regions and its high protein content. The current study presents a SWOT (strengths, weaknesses, opportunities, and threats) analysis to unravel the following: What are the strengths and weaknesses of Lathyrus spp. cultivation, what factors are opportunities or initiatives that encourage the adoption of the crop by growers, and what factors are disincentives or threats that prevent its adoption? What strategies could help expand cultivation? We use data from a questionnaire survey of farmers in Central Greece (Thessaly) to examine their attitudes and perceptions with regards to the above questions. The outcome of this study strongly suggests that farmers are willing to adopt the new Lathyrus spp. cultivation if they are assisted via contractualization, training, and new financial tools. Full article

(This article belongs to the Section Farming Sustainability)

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