Agronomy

Research

15 pages, 1995 KiB

Open AccessArticle

Impact of Reducing Nitrogen Fertilizer with Biochar on Flavor Substance and Nitrogen Balance in Different Swollen-Stem-Mustard Varieties

by Heng Zhang, Suikai Wang, Zhenya Tang and Qiliang Yang

Agronomy 2024, 14(6), 1254; https://doi.org/10.3390/agronomy14061254 - 11 Jun 2024

Viewed by 765

Abstract

Excessive application of nitrogen fertilizer in the swollen-stem mustard cultivation leads to a series of environmental and quality issues. It was reported that reducing nitrogen fertilizer with biochar could increase crop yield and reduce environmental risks. However, the effect of nitrogen reduction combined [...] Read more.

Excessive application of nitrogen fertilizer in the swollen-stem mustard cultivation leads to a series of environmental and quality issues. It was reported that reducing nitrogen fertilizer with biochar could increase crop yield and reduce environmental risks. However, the effect of nitrogen reduction combined with biochar application on the flavor substances was rarely reported. Thus, two genetic stem mustard varieties (Yx: Yong’an xiaoye and Fz: Fuza No. 2), and four N treatments (control: 0 N kg/ha with biochar; N150: 150 N kg/ha with biochar, N300: 300 N kg/ha with biochar, and N450: 450 N kg/ha) were chosen to study the effects of nitrogen reduction combined with biochar on the flavor substance content of mustard stem, and N balance. The results showed that the residual soil inorganic N in N300 was lower by 37% than that in N450 (156.5 kg/ha) in Fz mustard soil, and lower by 33% in N150 than in N450 (163.1 kg/ha) in Yx mustard. The highest biomass of stem mustard tumors of Fz (35.4 × 10³ kg/ha) and Yx (35.7 × 10³ kg/ha) was in N300. The content of umami amino acids, sweet amino acids, and bitter amino acids of Yx and Fz stem was the highest in N450, and N300, respectively. After comprehensive consideration, the Fz was recommended to be planted in the Three Gorges Reservoir Area with N300. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

24 pages, 11202 KiB

Open AccessArticle

Optimizing Irrigation and Fertilization to Simultaneously Improve Potato Tuber Yield, Water and Fertilizer Use Efficiency and Net Income in Northwest China

by Fan Zhang, Mengru Chen, Yu Zheng, Yunxia Xie and Yingying Xing

Agronomy 2024, 14(6), 1124; https://doi.org/10.3390/agronomy14061124 - 24 May 2024

Viewed by 722

Abstract

Irrigation, fertilization, and variety are important factors affecting potato production in northwest China. Field experiments (2021 and 2022) were performed to investigate the effects of irrigation and fertilization on the plant growth and soil microbial population of different potato varieties. Three irrigation levels [...] Read more.

Irrigation, fertilization, and variety are important factors affecting potato production in northwest China. Field experiments (2021 and 2022) were performed to investigate the effects of irrigation and fertilization on the plant growth and soil microbial population of different potato varieties. Three irrigation levels were used, i.e., 100% ETc (W1), 80% ETc (W2), and 60% ETc (W3), with ETc standing for crop evapotranspiration. Three fertilization levels were used (N-P-K), i.e., 240-120-300 kg ha⁻¹ (F1), 180-90-225 kg ha⁻¹ (F2), and 120-60-150 kg ha⁻¹ (F3). Three variety types were used, i.e., Feiurita (V1), Longshu 7 (V2), and Qingshu 9 (V3). These factors significantly influenced tuber yield (TY), net income (NI), and water productivity (WP). TY, NI, WP, total nitrogen accumulation (TNA), and nitrogen use efficiency (NUE) peaked at F2. Fertilization significantly impacted soil bacteria quantity (SBQ), fungi quantity (SFQ), and actinomycetes quantity (SAQ). TY, NI, SBQ, SFQ, and SAQ were highest at W2. Soil microbial population was strongly correlated with TY, NI, WP, TNA, and NUE. Comprehensively, this study suggests that irrigation that is varied from 248 to 266 mm, and fertilization (N-P-K) that is varied from 149.09-74.55-186.36 to 212.73-106.36-265.91 kg ha⁻¹ can promote the potato industry’s sustainable development and provide important references for the optimal field management of potato cultivation in northwest China. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

22 pages, 2391 KiB

Open AccessArticle

Appropriate Water and Nitrogen Regulation Improves the Production of Wolfberry (Lycium barbarum L.)

by Yalin Gao, Jinghai Wang, Yanlin Ma, Minhua Yin, Qiong Jia, Rongrong Tian, Yanxia Kang, Guangping Qi, Chen Wang, Yuanbo Jiang and Haiyan Li

Agronomy 2024, 14(3), 607; https://doi.org/10.3390/agronomy14030607 - 18 Mar 2024

Cited by 1 | Viewed by 946

Abstract

Wolfberry (Lycium barbarum L.) production in arid and semi-arid areas is drastically affected by the low utilization rate of soil and water resources and the irrational application of water and nitrogen fertilizers. Thus, this study explored a high-yielding, high-quality, and efficient irrigation [...] Read more.

Wolfberry (Lycium barbarum L.) production in arid and semi-arid areas is drastically affected by the low utilization rate of soil and water resources and the irrational application of water and nitrogen fertilizers. Thus, this study explored a high-yielding, high-quality, and efficient irrigation and nitrogen regulation model to promote the production efficiency of wolfberry and rational utilization of water and land resources in arid and semi-arid areas. We compared and analyzed the effects of different soil water treatments (the upper and lower limits of soil water were estimated as the percentage of soil water content to field water capacity (θ_f), with the following irrigation regimen: adequate irrigation (W0, 75–85% θ_f), mild water deficit (W1, 65–75% θ_f), moderate water deficit (W2, 55–65% θ_f), and severe water deficit (W3, 45–55% θ_f)) and nitrogen levels (no nitrogen (N0, 0 kg·ha⁻¹), low nitrogen (N1, 150 kg·ha⁻¹), moderate nitrogen (N2, 300 kg·ha⁻¹), and high nitrogen (N3, 450 kg·ha⁻¹)) on the growth, physiology, and production of wolfberry. The results showed that water regulation, nitrogen application level, and their interaction significantly affected plant height and stem diameter growth amount (p < 0.05). Additionally, the relative chlorophyll content of wolfberry leaves first increased and then decreased with increasing nitrogen levels and water deficit. The average net photosynthetic rate (P_n), stomatal conductance (g_s), intercellular carbon dioxide concentration, and transpiration rate (T_r) reached the highest values in plants exposed to W0N2 (19.86 μmmol·m⁻²·s⁻¹), W1N1 (182.65 mmol·m⁻²·s⁻¹), W2N2 (218.86 μmol·mol⁻¹), and W0N2 (6.44 mmol·m⁻²·s⁻¹) treatments, respectively. P_n, g_s, and T_r were highly correlated with photosynthetically active radiation and water vapor pressure difference (goodness-of-fit: 0.366–0.828). Furthermore, water regulation and nitrogen levels exhibited significant effects on the yield and water- (WUE), and nitrogen-use efficiency (NUE) (p < 0.01), and their interactions exhibited significant effects on the yield, WUE, and nitrogen partial productivity of wolfberry plants (p < 0.05). Moreover, the contents of total sugar, polysaccharides, fats, amino acids, and proteins were the highest in W1N2, W1N2, W1N2, W2N3, and W0N2 treatments, respectively, which were increased by 3.32–16.93%, 7.49–54.72%, 6.5–45.89%, 11.12–86.16%, and 7.15–71.67%, respectively. Under different water regulations (except for the W3 condition) and nitrogen level treatments, the net income and input–output ratio of wolfberry were in the order W1 > W0 > W2 > W3 and N2 > N3 > N1 > N0. The TOPSIS method also revealed that the yield, quality, WUE, NUE, and economic benefits of wolfberry improved under the W1N2 treatment, suggesting that WIN2 might be the most suitable irrigation and nitrogen regulation model for wolfberry production in regions with scarce land and water resources such as the Gansu Province and areas with similar climate. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

19 pages, 4455 KiB

Open AccessArticle

Effects of Combined Application of Biological Agent and Fertilizer on Fungal Community Structure in Rhizosphere Soil of Panax notoginseng

by Yanwei Liu, Yingjie Zhou, Xiaofan Zhang, Ni Cao, Bin Li, Jiaping Liang and Qiliang Yang

Agronomy 2023, 13(8), 2093; https://doi.org/10.3390/agronomy13082093 - 9 Aug 2023

Cited by 2 | Viewed by 1282

Abstract

The fungal community structure and soil fertility in rhizosphere soil have an important effect on the health of Panax notoginseng (P. notoginseng). The attack of pathogenic fungi and the imbalance of soil fertility can easily lead to diseases. The effect of [...] Read more.

The fungal community structure and soil fertility in rhizosphere soil have an important effect on the health of Panax notoginseng (P. notoginseng). The attack of pathogenic fungi and the imbalance of soil fertility can easily lead to diseases. The effect of Bacillus subtilis on improving the community structure of soil fungi has been confirmed, and the corresponding biological agent products have been commercialized. A pot experiment carried out in a greenhouse explored the effect of a biological agent and fertilizer on the fungal community in the rhizosphere of P. notoginseng. In the experiment, fertilization and the addition of biological agents were set up with three gradients, respectively, and the full coupling experiment was adopted, and the blank control group (CK) was set up at the same time. Therefore, there were thirteen treatments in the experiment. NH4 decreased between 36.42% and 11.56%, AP increased between 6.03% and 92.46%, AK increased between 2.99% and 25.40%, TN increased between 0.10% and 9.41%, and TP increased by 18.25% to 47.73% The addition of Bacillus subtilis biological agent decreased the Chao1, Shannon, Simpson, and ACE index of fungi in the rhizosphere soil of P. notoginseng. The Chao1 index decreased between 0.39% and 78.22%; the ACE index decreased between 0.43% and 78.24%. The main pathogenic fungi Cylindrocarpon and Fusarium of P. notoginseng were different in the experimental results. Cylindrocarpon decreased under F1C1, F2C1, and F3C2 treatments, while Fusarium increased under F1C1, F2C2, F3C1, and F3C3 treatments and decreased Fusarium content in rhizosphere soil of P. notoginseng in other treatments. RDA analysis (Redundancy analysis) showed that NH4-N was negatively correlated with the main pathogen Cylindrocarpon, Fusarium, and Ilyonectria, while AP and AK were positively correlated with Cylindrocarpon, Fusarium, and Ilyonectria. The results of the GRA-TOPSIS analysis showed that the score of F3C2 was the highest, while F2C3 and F2C1 ranked second and third, respectively. The calculation results of the theoretical model based on GRA-TOPSIS analysis showed that the GRA-TOPSIS score was highest when the theoretical optimal fertilizer application rate and bacteria application rate were 116.31 kg hm⁻² and 15.83 kg hm⁻², respectively. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

20 pages, 4765 KiB

Open AccessArticle

Scale Effects on the Reduction of Drainage Water and Nitrogen and Phosphorus Loads in Hilly Irrigation Areas

by Niannian Yuan, Yalong Li, Yujiang Xiong, Baokun Xu, Fengli Liu and Haolong Fu

Agronomy 2023, 13(8), 2083; https://doi.org/10.3390/agronomy13082083 - 8 Aug 2023

Cited by 1 | Viewed by 1035

Abstract

The objectives of this study were to clarify the effects of scale on farmland drainage water and the nitrogen and phosphorusload discharged in hilly irrigation areas. An experimental study was conducted to monitor the drainage water volume and nitrogen and phosphorus concentrations at [...] Read more.

The objectives of this study were to clarify the effects of scale on farmland drainage water and the nitrogen and phosphorusload discharged in hilly irrigation areas. An experimental study was conducted to monitor the drainage water volume and nitrogen and phosphorus concentrations at the field, lateral ditch (with a control area of 1.16 km²), branch ditch (with a control area of 7.76 km²), and watershed (with a control area of 43.3 km²) scales in the Yangshudang watershed of the Zhanghe Irrigation District during the rice growth period in 2022. The results showed that from the field scale to the watershed scale, the volume of drainage water, total nitrogen load, nitrate nitrogen load, ammonia nitrogen load, and total phosphorus load per unit area were reduced by 74.6%, 88%, 85%, 87%, and 60%, respectively. The loads of total nitrogen, nitrate nitrogen, ammonia nitrogen, and total phosphorus decreased with the increase of scale, showing a pronounced scale effect; however, the infrequent recharge of ponds and weirs and the insufficient storage capacity of ditches led to an increase in nitrogen and phosphorus concentrations and hence an increase in the load discharge instead, as in the branch ditch scale of this study. The scale effect was mainly caused by the reuse of farmland drainage water; thus, the ability of ponds and weirs, ditches, and reservoirs in hilly irrigation areas to regulate nitrogen and phosphorus concentrations should be improved. Irrigation methods have a significant influence on nitrogen and phosphorus load discharge. The control of farmland non-point sources in hilly irrigation areas should focus on controlling drainage water at the late tillering stage and improving the recharge function of ponds and weirs and the storage capacity of ditches above the branch ditch scale so as to control the concentrations of nitrogen and phosphorus pollutants. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

18 pages, 17005 KiB

Open AccessArticle

Spatiotemporal Variability of Soil Water Content and Its Influencing Factors on a Microscale Slope

by You Hu, Chongjun Tang, Xiaoan Chen, Ying Zhao, Hailong He, Min Li and Jie Zhang

Agronomy 2023, 13(8), 2035; https://doi.org/10.3390/agronomy13082035 - 31 Jul 2023

Viewed by 1246

Abstract

In order to enhance food security and promote sustainable agricultural development, there is extensive utilization of sloping land in China. However, soil and water loss are severe in sloping lands. Understanding the spatiotemporal variability of soil water content (θ) is therefore [...] Read more.

In order to enhance food security and promote sustainable agricultural development, there is extensive utilization of sloping land in China. However, soil and water loss are severe in sloping lands. Understanding the spatiotemporal variability of soil water content (θ) is therefore important for determining suitable soil and water conservation strategies. Nevertheless, there exists a dearth of current research that focuses on the spatiotemporal variability of θ in microscale sloping lands. This study used statistical and temporal stability (TS) analyses to explore the characteristics of the spatiotemporal variability of θ on slopes. Furthermore, this study aimed to quantify the impacts of soil depth, slope position, air temperature, and hydrological conditions on the TS of θ. The average θ increases with depth, and it follows a logarithmic increase above 1.3 m and a linear increase below 1.3 m. The spatial variability of θ is higher in shallow soils and wet seasons compared with deep soils and dry seasons. The temporal stability of θ is higher on the upper and lower slopes compared with the middle slope. Day-MRD is more effective at capturing the temporal stability of θ than all-MRD. The diurnal variation of the TS of θ on slopes is primarily influenced by soil depth, slope position, air temperature, and hydrological conditions. We found that soil depth had a greater impact on the TS of θ than the slope position and that air temperature has a greater influence than the hydrological conditions. This study accurately describes the spatiotemporal variability of θ at the microscale slope, which helps solve the problems of soil and water conservation and water resource management on slopes. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

19 pages, 1747 KiB

Open AccessArticle

The Mechanisms of Different Light Supply Patterns in the Nutrient Uptake and Chlorophyll Fluorescence of Hydroponic Lettuce

by Yanwei Liu, Ni Cao, Xiaolan Shi, Fei Meng, Yingjie Zhou, Haidong Wang and Qiliang Yang

Agronomy 2023, 13(7), 1910; https://doi.org/10.3390/agronomy13071910 - 20 Jul 2023

Cited by 3 | Viewed by 1849

Abstract

Vertical agriculture has developed rapidly in recent years, pushing artificial light planting to new heights. Under indoor artificial light, the light supply mode has practical significance in studying the impact of lighting conditions on plants. This experiment involved five intermittent light supply modes [...] Read more.

Vertical agriculture has developed rapidly in recent years, pushing artificial light planting to new heights. Under indoor artificial light, the light supply mode has practical significance in studying the impact of lighting conditions on plants. This experiment involved five intermittent light supply modes (with a light period of 16 h and a dark period of 8 h (16/8) as the control group, with a light period of 8 h and a dark period of 4 h repeated twice a day (8/4), a light period of 4 h and a dark period of 2 h repeated four times a day (4/2), a light period of 2 h and a dark period of 1 h repeated eight times a day (2/1), and a light period of 1 h and a dark period of 0.5 h repeated 16 times a day (1/0.5) (as the experimental groups). A total of ten treatments were combined before the continuous light supply mode (B) and after the continuous light supply mode (A). Through experimental settings, we explored the response mechanisms to intermittent and continuous light supply modes as they pertain to lettuce growth, nutrient content, photosynthetic parameters, and light stress. Through research, it was found that continuous light supply significantly increased plant height, root length, aboveground dry and fresh weight, and the underground dry and fresh weight of lettuce. The treatments with a light period 4 h/dark period 2 h (4/2) and a light period 8 h/dark period 4 h (8/4) significantly increased the N, P, K, and Cu contents. Additionally, continuous light supply helped stabilize the Mg, Ca, and Mn contents across all treatment groups. Stomatal closure has been found to cause a decrease in the rate of net photosynthesis, transpiration, and intercellular CO₂ concentration. The energy absorbed by antenna pigments is significantly increased when participating in photochemical reactions; however, continuous light supply has been observed to reduce the absorption flux per reaction center (ABS/RC), trapped energy flux per reaction center (TR₀/RC), electron transport flux per reaction center (ET₀/RC), and the probability that a trapped exciton moves an electron into the electron transport chain beyond QA⁻ (at t = 0) (ET₀/TR₀). Conversely, the electron transport flux per cross section (ET₀/CS) has been found to increase significantly. In summary, among the intermittent light supply treatment groups, the 2/1 treatment group showed the best response to growth indicators, nutrient absorption, and photosynthesis, and could improve the quality of lettuce without adding additional light energy. Continuous light supply in the short term can improve the growth and nutrient absorption of lettuce; both of the two light supply modes produced light stress on lettuce, and this light stress caused by non-circadian rhythm forced the lettuce to increase its photochemical quenching (qI) and electro transport flux crossover (ET₀/CS). This paper may provide a theoretical reference for the use of light supply modes in plant factories to improve vegetable yield, and for the study of the response mechanism of light stress under non-circadian rhythm. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

16 pages, 4770 KiB

Open AccessArticle

Intelligent Control Technology and System of on-Demand Irrigation Based on Multiobjective Optimization

by Weibing Jia, Zhengying Wei, Xiangyi Tang, Yubin Zhang and Ao Shen

Agronomy 2023, 13(7), 1907; https://doi.org/10.3390/agronomy13071907 - 19 Jul 2023

Cited by 1 | Viewed by 1304

Abstract

To solve the problem that the parameters of the multiple-input multiple-output (MIMO) irrigation system are difficult to control accurately, an on-demand irrigation control experimental device was developed. The main input parameters of the device are the opening degree of the main pipe valve, [...] Read more.

To solve the problem that the parameters of the multiple-input multiple-output (MIMO) irrigation system are difficult to control accurately, an on-demand irrigation control experimental device was developed. The main input parameters of the device are the opening degree of the main pipe valve, the opening frequency of and the pump station, the opening degree of the branch pipeline valve with the different combinations of different opening degrees. Based on these input parameters, four types of experimental methods were designed, and a total of 1695 groups of experiments were designed. The results show that the different opening degree combinations of the branch electric valve cannot significantly affect the flow of the branch pipeline but also significantly affect the pressure of the main pipeline. The prediction error of the operating frequency of the pump station and the opening degree of the branch valve were regarded as the objective function. Six intelligent prediction models were constructed, which are Back Propagation (BP), support vector regression (SVR) Linear, SVR-RBF, SVR-Poly, random forest (RF) and eXtreme Gradient Boosting (XGBoost), respectively. The results show that the XGBoost is the best model among the six models. For the opening degree of three branch valves, the mean absolute error (MAE) between the predicted value and actual value is less than 3.3%, the mean square deviation (RMSE) between the predicted values and actual values is less than 4.5%, and the R² of between the predicted values and actual values is greater than 0.990. The control models and system can meet the needs of an on-demand irrigation system. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

17 pages, 3645 KiB

Open AccessArticle

Analysis and Prediction of the Impact of Socio-Economic and Meteorological Factors on Rapeseed Yield Based on Machine Learning

by Jiaping Liang, Hang Li, Na Li, Qiliang Yang and Linchao Li

Agronomy 2023, 13(7), 1867; https://doi.org/10.3390/agronomy13071867 - 14 Jul 2023

Cited by 2 | Viewed by 1911

Abstract

Rapeseed is one of China’s major oil crops, and accurate yield forecasting is crucial to the growth of the rapeseed industry and the country’s food security. In this study, the data on natural and socio-economic factors from 2001 to 2020 and the yield [...] Read more.

Rapeseed is one of China’s major oil crops, and accurate yield forecasting is crucial to the growth of the rapeseed industry and the country’s food security. In this study, the data on natural and socio-economic factors from 2001 to 2020 and the yield of rapeseed in China were used as the data basis. The Pearson correlation coefficient was used to analyze the relationship between the influencing factors and the yield of rapeseed, and the prediction effect of four machine learning models (linear regression (LR), decision tree (DTR), random forest (RF), and support vector machine (SVM)) on the yield of rapeseed was compared in China’s main rapeseed-producing area. The results demonstrate that the yield of rapeseed in China showed an increasing trend, but fluctuated greatly. Rural electricity consumption, gross agricultural production, the net amount of agricultural fertilizer application, effective irrigation area, total power of agricultural machinery, and consumption of agricultural plastic film had a positive effect on the increase in rapeseed yield. However, due to the impact of climate change and disasters, the yield of rapeseed has had significant fluctuations. A Pearson correlation analysis showed that socio-economic factors (rural electricity consumption, gross agricultural production, effective irrigation area, total power of agricultural machinery, consumption of agricultural plastic film, etc.) played a dominant role in rapeseed yield changes. The RF model had a good prediction effect on rapeseed yield, and natural factors and socio-economic factors had different effects on spring rapeseed and winter rapeseed. Winter rapeseed yield was mainly affected by socio-economic factors, accounting for as high as 89% of the importance. Among them, the sown area of rapeseed and the effective irrigation area had the greatest impact. The effects of natural factors and socio-economic factors on spring rapeseed yield were similar, accounting for 47% and 53%, respectively, and the mean annual precipitation, sunshine duration, and sown area of rapeseed were the most influential variables. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

14 pages, 2171 KiB

Open AccessArticle

Straw Returning Measures Enhance Soil Moisture and Nutrients and Promote Cotton Growth

by Min Tang, Rui Liu, Zhenhai Luo, Chao Zhang, Jiying Kong and Shaoyuan Feng

Agronomy 2023, 13(7), 1850; https://doi.org/10.3390/agronomy13071850 - 13 Jul 2023

Cited by 4 | Viewed by 1612

Abstract

In order to investigate the comprehensive effects of straw returning on soil physical and chemical properties, as well as cotton growth in Jiangsu, China, and to determine suitable high-yield and efficient straw returning measures, this study implemented three different straw returning methods: straw [...] Read more.

In order to investigate the comprehensive effects of straw returning on soil physical and chemical properties, as well as cotton growth in Jiangsu, China, and to determine suitable high-yield and efficient straw returning measures, this study implemented three different straw returning methods: straw mulching (SM), straw incorporation (SI), and straw biochar (BC), with no straw returning served as a control (CT). The study aimed to assess the impact of these straw-returning measures on soil nutrients, soil moisture content, soil water storage, and deficit status, as well as primary indicators of cotton growth. The findings revealed that the total available nutrient storage under SM, SI, and BC showed an increase of 11.93%, 11.15%, and 32.39%, respectively, compared to CT. Among these methods, BC demonstrated a significant enhancement in soil organic carbon content, available phosphorus, and available potassium. Furthermore, SM exhibited a considerable increase in soil moisture content across all layers (0–40 cm), resulting in an average water storage increase of 7.42 mm compared to CT. Consequently, this effectively reduced the soil water deficit during the cotton development period. Moreover, the height of cotton plants was increased by SM, SI, and BC, with SM promoting the greatest growth rate of up to 66.87%. SM resulted in an 11.17 cm increase in cotton plant height compared to CT. Additionally, SM contributed to higher chlorophyll content in leaves at the end of the growth period. Overall, the indicators suggest that straw mulching is particularly effective in enhancing soil moisture and nutrient distribution, especially during dry years, and has a positive impact on promoting cotton development. Based on the results, straw mulching emerges as a recommended straw-returning measure for improving soil quality and maximizing cotton production in the study area. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

15 pages, 1666 KiB

Open AccessArticle

Nitrogen Application Alleviates Impairments for Jatropha curcas L. Seedling Growth under Salinity Stress by Regulating Photosynthesis and Antioxidant Enzyme Activity

by Zhao Yang, Shuai Tan, Qiliang Yang, Shaomin Chen, Changmin Qi, Xiaogang Liu, Jiaping Liang and Haidong Wang

Agronomy 2023, 13(7), 1749; https://doi.org/10.3390/agronomy13071749 - 28 Jun 2023

Cited by 4 | Viewed by 1163

Abstract

Jatropha curcas L. is a promising bioenergy source, and its seedling stage is sensitive to salinity. Nitrogen application presents an effective strategy for alleviating the adverse consequences of salinity stress. However, the responses of plant growth and physiology of Jatropha curcas L. seedlings [...] Read more.

Jatropha curcas L. is a promising bioenergy source, and its seedling stage is sensitive to salinity. Nitrogen application presents an effective strategy for alleviating the adverse consequences of salinity stress. However, the responses of plant growth and physiology of Jatropha curcas L. seedlings to nitrogen application under salinity stress remain unclear. As a result, a one-year greenhouse plot experiment was conducted to investigate the effects of nitrogen application on the plant growth, antioxidant enzyme activity, and photosynthesis of Jatropha curcas L. seedlings under saline conditions. Experiment treatments consisted of three salinity stresses (mild salinity stress, S1: 2 g/kg; moderate salinity stress, S2: 4 g/kg; and severe salinity stress, S3: 6 g/kg), four nitrogen application rates (N0: 0 gN/plant; N1: 20 gN/plant; N2: 60 gN/plant; and N3: 100 gN/plant), and a control treatment (CK) which was without salinity stress and nitrogen application. The results showed that salinity stress substantially reduced plant growth of Jatropha curcas L. seedlings. As the salinity stress increased, the reduction in plant growth also increased. The S3 treatment had the lowest leaf area, leaf biomass, and total biomass, which decreased by an average of 70.4%, 66.3%, and 69.9%, respectively, compared to CK. Nitrogen application could compensate for these impairments of plant growth from salinity stress by promoting antioxidant enzyme activity and photosynthesis. As for mild and moderate salinity stresses, the maximum plant growth was found in the N3 treatment, with the maximum antioxidant enzyme activity, photosynthetic pigment, photosynthetic characteristic, and chlorophyll fluorescence. As for severe salinity stress, higher plant growth was found in N2 and N3 treatments, and there were no significant differences between N2 and N3 treatments. It also should be noted that the maximum photosynthetic characteristic and chlorophyll fluorescence were found in N2 treatment under severe salinity stress. In conclusion, nitrogen application could be an alternative strategy to improve the salinity tolerance of Jatropha curcas L. growth. The nitrogen application rate of 100 gN/plant could be recommended for low and moderate salinity stresses, while 60 gN/plant could be recommended for severe salinity stress. However, higher nitrogen application rate (>100 gN/plant) under mild and moderate salinity stress and the effects of reactive oxygen species under salinity stress should be further evaluated. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

20 pages, 2689 KiB

Open AccessArticle

Coupling Effect of Water and Soluble Organic Fertilizer on Yield and Quality of Panax notoginseng under Micro-Sprinkler Irrigation in Southwest China

by Tianqi Mu, Xiulu Yue, Zhennan Zang, Haidong Wang, Jiaping Liang, Qiliang Yang, Jinjin Guo, Na Li, Xiaogang Liu and Qi You

Agronomy 2023, 13(7), 1742; https://doi.org/10.3390/agronomy13071742 - 28 Jun 2023

Cited by 5 | Viewed by 1578

Abstract

The cultivation of Panax notoginseng has been plagued by a multitude of challenges, including recurrent diseases, suboptimal value, inadequate quality, and environmental degradation resulting from improper water and fertilizer management. To address these issues and improve the yield of P. notoginseng and its [...] Read more.

The cultivation of Panax notoginseng has been plagued by a multitude of challenges, including recurrent diseases, suboptimal value, inadequate quality, and environmental degradation resulting from improper water and fertilizer management. To address these issues and improve the yield of P. notoginseng and its saponin content, this study endeavors to identify the optimal irrigation and fertilization levels in shaded environments in Yunnan Province in Southwest China. In this field experiment, three-year-old plants were tested to evaluate the effects of water, soluble organic fertilizers, and their combinations on plant growth, physiological parameters, yield, and saponin content. The experiment included 12 treatments with three types of irrigation (10 (W₁), 15 (W₂), and 20 (W₃) mm), totaling 440, 660, and 880 mm, and four levels of the total amount of fertilization (F₁ (60, total N 12.6, total P 5.5, and total K 10.5 kg ha⁻¹), F₂ (90, total N 18.9, total P 8.3, and total K 15.7 kg ha⁻¹), F₃ (120, total N 25.2, total P 11.0, and total K 20.9 kg ha⁻¹), F₄ (150, total N 31.5, total P 13.8, and total K 26.1 kg ha⁻¹)). The randomized complete block design was used, with 36 plots in total and 3 replications. The study utilized the TOPSIS method to determine the most effective water and fertilizer management strategy for the growth and production of P. notoginseng. The assessment of yield, water and fertilizer productivity, and saponin content across all treatments revealed that the W₃F₃ treatment resulted in significant increases in the plant’s height, stem diameter, and net photosynthetic rate. Meanwhile, the W₂F₃ treatment exhibited the best root morphological traits. The W₃F₄ treatment effectively increased dry matter and transpiration. The combination of water and fertilization had a coupling effect that not only increased yield to 1400 kg ha⁻¹ but also improved water–fertilizer productivity. The application of the W₂F₃ treatment resulted in a significant increase in the accumulation of active components, leading to a total P. notoginseng saponin (PNS) content of 24.94%. Moreover, the comprehensive index obtained through the TOPSIS model indicated that the W₂F₃ treatment outperformed other treatments. Therefore, this treatment can be considered a promising water and fertilizer model for P. notoginseng cultivation, which can enhance its yield, quality, and productivity while promoting sustainable green development. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

11 pages, 4261 KiB

Open AccessArticle

Coupled Dynamics of Soil Water and Nitrate in the Conversion of Wild Grassland to Farmland and Apple Orchard in the Loess Drylands

by Yanwei Lu, Peiyue Li, Min Li, Mingyi Wen, Haoyan Wei and Zhiqiang Zhang

Agronomy 2023, 13(7), 1711; https://doi.org/10.3390/agronomy13071711 - 26 Jun 2023

Cited by 2 | Viewed by 1211

Abstract

Understanding the dynamics of soil water and nitrate in response to typical agricultural crops in dryland ecosystems are crucial for assessing ecological consequences and informing land use planning. This study was conducted in the Changwu tableland, a representative area for agricultural crop cultivation [...] Read more.

Understanding the dynamics of soil water and nitrate in response to typical agricultural crops in dryland ecosystems are crucial for assessing ecological consequences and informing land use planning. This study was conducted in the Changwu tableland, a representative area for agricultural crop cultivation in the Loess Plateau of China. Fifteen soil profiles, including grassland, farmland, and young, mature, and old apple orchards, were sampled to investigate the effects of different land uses on soil water and nitrate dynamics using a “space-for-time” substitution approach. The results showed that the soil water content and nitrate content in farmlands were comparable to those in wild grassland. However, significant differences in soil water were observed below a depth of 2 m in apple orchards, with mature and old orchards experiencing water deficits compared to grassland of 624.9 mm and 690.0 mm, respectively. Moreover, a dried soil layer formed below a depth of 5 m in these orchards. In terms of soil nitrate, the concentration in the 0–5 m depth of apple orchards was significantly higher than that in agricultural land and grassland, and it increased with the age of the orchards. However, below 5 m, the residual nitrate stock per unit depth in apple orchards decreased to levels comparable to grassland and farmland, primarily due to the inhibitory effect of the dried soil layer on downward migration and leaching processes. Furthermore, the relationship between nitrate and soil water at 0–5 m soil depths differed during the conversion from grassland to farmland and apple orchard, with positive and negative correlations observed, respectively. This indicates that water plays a key role in influencing nitrate movement, and distinct hydrological processes occur for soil water and nitrate nitrogen under different land use change conditions. In conclusion, converting grassland and farmland to apple orchards can lead to soil water decline and nitrate accumulation in the vadose zone, posing potential threats to ecosystem sustainability and security in dryland regions. Therefore, implementing appropriate water-fertilizer management practices is crucial for promoting sustainable land use in loess drylands, with potential implications for similar areas worldwide. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

14 pages, 7423 KiB

Open AccessArticle

An Improved Craig–Gordon Isotopic Model: Accounting for Transpiration Effects on the Isotopic Composition of Residual Water during Evapotranspiration

by Yanwei Lu, Mingyi Wen, Peiyue Li, Jiaping Liang, Haoyan Wei and Min Li

Agronomy 2023, 13(6), 1531; https://doi.org/10.3390/agronomy13061531 - 31 May 2023

Cited by 2 | Viewed by 2050

Abstract

Evapotranspiration (ET) is a crucial process in the terrestrial water cycle, and understanding its stable isotopic evolution is essential for comprehending hydrological processes. The Craig–Gordon (C-G) model is widely used to describe isotopic fractionation during pure evaporation. However, in natural environments, ET involves [...] Read more.

Evapotranspiration (ET) is a crucial process in the terrestrial water cycle, and understanding its stable isotopic evolution is essential for comprehending hydrological processes. The Craig–Gordon (C-G) model is widely used to describe isotopic fractionation during pure evaporation. However, in natural environments, ET involves both transpiration (T) and evaporation (E), and the traditional C-G model does not account for the effect of transpiration on isotopic fractionation. To address this gap, we propose the evapotranspiration-unified C-G (ET-UCG) model, which extends the C-G model by incorporating transpiration’s effect on water isotopes. We verified the validity of the ET-UCG model by comparing its simulation results with the traditional C-G model’s discrete results for a special scenario that simulated the isotopic evolution of residual water after daily transpiration consumption. Further, we simulated two different ET process scenarios using the ET-UCG model to investigate transpiration’s effect on the residual water’s isotopic composition. Our numerical experiments show that transpiration indirectly affects the degree of water isotope fractionation by reducing the true evaporation ratio, even though it does not directly produce isotope fractionation. Therefore, the isotopic composition of residual water estimated by the ET-UCG model is consistently lighter than that estimated using the traditional C-G model in the simulation of ET. Despite different T/ET conditions, the isotopic evolution process follows the same evaporation line. These results highlight the importance of considering transpiration effects when using the C-G model and provide valuable insights into ET processes with potential applications in the field. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

11 pages, 1468 KiB

Open AccessArticle

Long-Term Conservation Tillage Increases Yield and Water Use Efficiency of Spring Wheat (Triticum aestivum L.) by Regulating Substances Related to Stress on the Semi-Arid Loess Plateau of China

by Changliang Du, Lingling Li, Junhong Xie, Zechariah Effah, Zhuzhu Luo and Linlin Wang

Agronomy 2023, 13(5), 1301; https://doi.org/10.3390/agronomy13051301 - 5 May 2023

Cited by 2 | Viewed by 1711

Abstract

Improving the water-use efficiency (WUE) of crops is the most effective way to increase yields in semi-arid regions. Field research was carried out based on a long-term experiment initiated in 2001, aimed to explore the mechanisms of different tillage practices effects on grain [...] Read more.

Improving the water-use efficiency (WUE) of crops is the most effective way to increase yields in semi-arid regions. Field research was carried out based on a long-term experiment initiated in 2001, aimed to explore the mechanisms of different tillage practices effects on grain yield and WUE of spring wheat. Tillage practices in the research including conventional tillage (CT), no tillage with no straw mulching (NT), conventional tillage with straw incorporation (TS), and no tillage with straw mulching (NTS). The effects of tillage practices on soil’s physical and chemical properties, dry matter accumulation, grain yield, dynamics of stress-related substances, and WUE were observed. Soil and plant samples in this research were collected in 2020 (wet year), 2021 (dry year), and 2022 (dry year). The results indicated that NTS improved the soil’s physical and chemical properties. The NTS treatment had the lowest soil bulk and pH and the highest total N, NO₃^--N, and available P. Throughout the whole growth stage, soil water content in the NTS and TS treatments were significantly higher than that of CT by 8.77–20.40% and 2.19–18.83, respectively. Averaged catalase (CAT), peroxidase (POD), and soluble protein across the three years with NTS and TS were significantly increased by 1.26–25.52% compared to CT. Meanwhile, the NTS treatment had the lowest malondialdehyde (MDA) content among the different tillage practices. NTS maintained the highest dry matter accumulation throughout the whole growth stage among different treatments; it was increased by 10.47–73.33% compared with CT. The average grain yields and WUE of NTS across the three years were 6.09–30.70% and 6.79–40.55% higher than other tillage practices, respectively. It is concluded that NTS influences dry matter accumulation and water-use efficiency during the whole growth stage of spring wheat by improving the soil’s physicochemical properties and modulating spring wheat substances related to stress, which in turn promotes yield formation. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

18 pages, 3897 KiB

Open AccessArticle

Rain Shelter Cultivation Reduces Root Rot Incidence of Panax notoginseng by Altering Root Exudates and Bacterial Communities under Micro-Irrigation and Fertilization

by Yan Zhang, Jiaping Liang, Zhenya Tang and Qiliang Yang

Agronomy 2023, 13(5), 1257; https://doi.org/10.3390/agronomy13051257 - 28 Apr 2023

Cited by 5 | Viewed by 1725

Abstract

Panax notoginseng is an important medicinal crop in China. The high incidence of root rot in P. notoginseng during the rainy season has restricted the development of the industry. It is believed that frequent rainfall and a warm soil environment are important factors [...] Read more.

Panax notoginseng is an important medicinal crop in China. The high incidence of root rot in P. notoginseng during the rainy season has restricted the development of the industry. It is believed that frequent rainfall and a warm soil environment are important factors that promote root rot incidence. However, there is still a significant knowledge gap in the relationship between rainfall and root rot incidence. To understand the effects of rainfall and fertilizer on root exudates, the soil bacterial structure, and root rot in P. notoginseng, four treatments were chosen for both field and pot experiments. These treatments included DW (rain shelter and no fertilizer), RW (no rain shelter and no fertilizer), DWF (rain shelter and fertilizer), and RWF (no rain shelter and fertilizer). The results showed that both factors (rain shelter and fertilizer) significantly affected root rot incidence and several other parameters. Among them, the effect of a rain shelter is more significant than that of fertilizer, and the combination of the two further improves the effect. DW and DWF treatments significantly reduced the soil moisture, phenolic acid, and root rot incidence, while significantly increasing the soil temperature and enzyme activities compared to RW or RWF. Seven phenolic acids secreted by P. notoginseng roots were all positively correlated with root rot incidence. Root rot was also positively correlated with Planctomycetota, Acidobacteriota, and Gemmatimonadota and negatively correlated with Firmicutes, Proteobacteria, Patescibacteria, and Nitrospirota. DWF treatment decreased the soil moisture and the concentration of p-hydroxybenzoic acid, syringic acid, phthalic acid, and vanillic acid and promoted the growth of Firmicutes and Proteobacteria, leading to the lowest incidence of root rot. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

19 pages, 8806 KiB

Open AccessArticle

Combined Application of Coffee Husk Compost and Inorganic Fertilizer to Improve the Soil Ecological Environment and Photosynthetic Characteristics of Arabica Coffee

by Zeyin Jiang, Yuqiang Lou, Xiaogang Liu, Wenyan Sun, Haidong Wang, Jiaping Liang, Jinjin Guo, Na Li and Qiliang Yang

Agronomy 2023, 13(5), 1212; https://doi.org/10.3390/agronomy13051212 - 25 Apr 2023

Cited by 5 | Viewed by 2943

Abstract

Excessive use of chemical fertilizers deteriorates the soil environment and limits the normal growth of Arabica coffee trees. In order to identify the optimal coupling mode of chemical fertilizer application and biomass return that enhances the soil ecological environment and promotes the photosynthetic [...] Read more.

Excessive use of chemical fertilizers deteriorates the soil environment and limits the normal growth of Arabica coffee trees. In order to identify the optimal coupling mode of chemical fertilizer application and biomass return that enhances the soil ecological environment and promotes the photosynthetic efficiency of Arabica coffee, this study investigated the impacts of three levels of inorganic fertilizers (F_L: 360 kg·ha⁻¹, F_M: 720 kg·ha⁻¹, and F_H: 1080 kg·ha⁻¹) and three types of coffee husk returning methods (C_B: coffee husk biochar, C_C: coffee husk compost, C_A: coffee husk ash) on the soil fertility, microbial amount, enzyme activity, and photosynthetic characteristics of the Arabica coffee root zone. The entropy weight-TOPSIS method was employed to evaluate the comprehensive benefits. The results showed that F_M had the biggest effect on improving soil fertility, microorganisms, and enzyme activities compared with F_L and F_H. Moreover, compared to C_A, C_C significantly increased soil organic carbon, organic matter, and total nitrogen content. C_C significantly enhanced the activities of soil phosphatase and urease, respectively, by 29.84% and 96.00%, and significantly increased the amount of bacteria, fungi, and actinomycetes by 62.15%, 68.42%, and 46.21%, respectively. The net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (Gs) of F_MC_C were significantly higher than those of other treatments. The comprehensive benefit evaluation of the soil environment and photosynthetic characteristics by the entropy weight-TOPSIS method ranked F_MC_C first. Therefore, F_MC_C was the optimal coupling mode for fertilizer application and the coffee husk returning method. The findings of this study not only provide scientific guidance for fertilizing Arabica coffee but also clarify the proper approach to returning coffee husk to the field, thereby improving soil ecology and promoting green and efficient production of specialty crops. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

14 pages, 1029 KiB

Open AccessEditor’s ChoiceArticle

Effects of Two Biochar Types on Mitigating Drought and Salt Stress in Tomato Seedlings

by Wenqian Zhang, Jiahua Wei, Lili Guo, Heng Fang, Xiaojuan Liu, Kehao Liang, Wenquan Niu, Fulai Liu and Kadambot H. M. Siddique

Agronomy 2023, 13(4), 1039; https://doi.org/10.3390/agronomy13041039 - 31 Mar 2023

Cited by 24 | Viewed by 4078

Abstract

Biochar’s underlying biochemical and physiological mechanisms in reducing irrigation and salinity stress are elusive. This paper investigates the effects of two types of biochar (wood biochar and poultry biochar) on the growth and physiology of tomato seedlings exposed to the combined effects of [...] Read more.

Biochar’s underlying biochemical and physiological mechanisms in reducing irrigation and salinity stress are elusive. This paper investigates the effects of two types of biochar (wood biochar and poultry biochar) on the growth and physiology of tomato seedlings exposed to the combined effects of drought and salinity stress. Two types of biochar, wood biochar (WB) and poultry biochar (PB), were added to the soil separately, with three salinity gradients of 0, 100, and 200 mmol/L and two water supply conditions of full irrigation (FI) and deficit irrigation (DI). Results showed that biochar addition effectively improved the root water potential and osmotic potential of tomato plant under drought and salinity stress. Biochar application also mitigated leaf relative water content by 9.86% and 24.37% under drought and salinity stress, respectively. Furthermore, biochar application decreased abscisic acid concentrations in xylem sap under drought and salinity stress. Biochar altered the soil structure and increased field water holding capacity, indirectly increasing the soil water supply. While water use efficiency did not increase significantly after biochar application, a synergistic increase in seedling growth and water consumption occurred. In conclusion, biochar addition shows promise for promoting seedling growth to help mitigate the adverse impacts of drought and salinity stress on plant growth and physiology. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Graphical abstract

18 pages, 4887 KiB

Open AccessArticle

Short-Term Evapotranspiration Forecasting of Rubber (Hevea brasiliensis) Plantations in Xishuangbanna, Southwest China

by Zhen Ling, Zhengtao Shi, Tiyuan Xia, Shixiang Gu, Jiaping Liang and Chong-Yu Xu

Agronomy 2023, 13(4), 1013; https://doi.org/10.3390/agronomy13041013 - 30 Mar 2023

Cited by 2 | Viewed by 1554

Abstract

Rubber (Hevea brasiliensis) plantations have high water consumption through evapotranspiration, which can contribute to water scarcity. In addition, there is a lack of spatial observation data and estimation methods for evapotranspiration (ET) for rubber plantations. To alleviate the water [...] Read more.

Rubber (Hevea brasiliensis) plantations have high water consumption through evapotranspiration, which can contribute to water scarcity. In addition, there is a lack of spatial observation data and estimation methods for evapotranspiration (ET) for rubber plantations. To alleviate the water stress of expanding rubber plantations caused by seasonal drought in Xishuangbanna, Southwest China, an up to 7 days crop evapotranspiration (ET_c) forecast method, “K_c-ET₀” for rubber plantations with limited meteorological data, was proposed by using rubber crop coefficient K_c and public weather forecasts. The results showed that the average absolute error (MAE) of forecasted ET_c was 0.68 mm d⁻¹, the root mean square error (RMSE) was 0.85 mm d⁻¹, and the average correlation coefficient (R) was 0.69 during the rainy season, while during the dry season these metrics were 0.52 mm d⁻¹, 0.68 mm d⁻¹, and 0.85, respectively. The accuracy of ET_c forecast in the dry season was higher. Additionally, K_c was the main factor influencing the accuracy of rubber plantations ET_c forecast, while the accuracy of the temperature forecast and the chosen Hargreaves-Samani (HS) model were also considerable. Our results suggested that the “K_c-ET₀” short-term rubber plantation ET_c forecasting method shows good performance and acceptable accuracy, especially in the dry season. The study provides an important basis for creating ET-based irrigation scheduling for improving regional-scale water management in high water consumption rubber plantations. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

20 pages, 3402 KiB

Open AccessArticle

Bibliometric Analysis on the Impact of Climate Change on Crop Pest and Disease

by Qiliang Yang, Tianmu Du, Na Li, Jiaping Liang, Tehseen Javed, Haidong Wang, Jinjin Guo and Yanwei Liu

Agronomy 2023, 13(3), 920; https://doi.org/10.3390/agronomy13030920 - 20 Mar 2023

Cited by 7 | Viewed by 3504

Abstract

Affected by global warming, the frequency of crop pests and diseases have increased, causing huge losses to agricultural production. To better grasp the development and trends of research on the effects of climate change on crop pests and diseases, the literature on the [...] Read more.

Affected by global warming, the frequency of crop pests and diseases have increased, causing huge losses to agricultural production. To better grasp the development and trends of research on the effects of climate change on crop pests and diseases, the literature on the impact of climate change on crop pests and diseases published from 1990 to 2021 in the Web of Science (WOS) core collection database was used. This study explores the literature characteristics and hotspot evolution through the bibliometric visualization analysis software COOC, VOSviewer, and CiteSpace, with a view to identifying the changing characteristics and trends of research changes in this field. The results showed that the number of literature on the impact of climate change on crop pests and diseases increased rapidly. The main fields involved include environmental sciences, ecology, and agronomy. Papers in these fields mainly published in journals, such as PLos One, Forest Ecology and Management, and Frontiers in Plant Science. The country with the highest number of publications was the United States, followed by China and Australia. The most prolific authors in the top 20 are research scholars from China. The first author of the top 20 highly cited papers was from the United States. It was found that that current research on the impact of climate change on crop pests and diseases mainly focuses on agricultural production and food safety. Modelling and crop growth has maintained steady development. At present, research in this field mainly focuses on pest management strategies under the impact of climate change, the response of single species, and the complex ecological mechanisms behind the response. This study provides unique insights into the research field of the impact of climate change on crop pests and diseases and provides a reference direction for future research development in this field. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

16 pages, 3128 KiB

Open AccessArticle

Response of Water-Nitrogen Distribution and Use to Water Deficit under Different Applied Nitrogen Fertilizer Rates in Bromus inermis Grassland

by Yanxia Kang, Minhua Yin, Yanlin Ma, Zhongxia Tang, Qiong Jia, Guangping Qi, Jinghai Wang, Yuanbo Jiang and Aixia Wang

Agronomy 2023, 13(3), 745; https://doi.org/10.3390/agronomy13030745 - 3 Mar 2023

Cited by 4 | Viewed by 1718

Abstract

This study was about the water-nitrogen regulation model and its soil nutrient environment effect for increasing the yield and efficiency of Bromus inermis in the Hexi Corridor, Gansu Province, China. Bromus inermis was used as the research object in this study and four [...] Read more.

This study was about the water-nitrogen regulation model and its soil nutrient environment effect for increasing the yield and efficiency of Bromus inermis in the Hexi Corridor, Gansu Province, China. Bromus inermis was used as the research object in this study and four irrigation management types and four nitrogen application levels were set. The four irrigation management types (controlled by the percentage of field capacity (θ_f) at the jointing stage) were 75–85% (W0), 65–85% (W1), 55–85% (W2) and 45–85% (W3). The four nitrogen application levels were pure nitrogen 0 kg·ha⁻¹ (N0), 60 kg·ha⁻¹ (N1), 120 kg·ha⁻¹ (N2) and 180 kg·ha⁻¹ (N3). The effects of water-nitrogen regulation on the spatial and temporal distribution of soil moisture and nitrate nitrogen (NO₃⁻–N), plant height, chlorophyll content, yield and water-nitrogen use efficiency of Bromus inermis were studied. Results demonstrated that (1) soil water content (SWC) was mainly affected by irrigation and W1 treatment helped maintain shallow soil (0–40 cm) water’s stability and avoided water redundancy or deficit in the 60–80 cm soil layer. The distribution of soil NO₃⁻–N was mainly affected by nitrogen application. The N2 treatment could effectively increase the NO₃⁻–N content in shallow soil (0–40 cm) and prevent nitrate-nitrogen leaching in the 60–100 cm soil layer. (2) Irrigation and nitrogen application could significantly increase the plant height and chlorophyll content of each cut of Bromus inermis. The average plant height and chlorophyll content of the N2W1 treatment were 66.99% and 30.30% higher than N0W3. (3) At the same time, irrigation and nitrogen application could significantly increase the yield of each cut of Bromus inermis, and the interaction between the two had a significant effect on the total yield. The total yield of the N2W1 treatment was the highest (12,259.54 kg·ha⁻¹), 157.95% higher than N0W3. Irrigation and nitrogen application could significantly improve the water-nitrogen use efficiency of Bromus inermis, and their interaction only significantly impacted the partial-factor productivity of the applied nitrogen (PFP_N). Meanwhile, the N2W2 treatment had the highest water use efficiency (WUE) (23.12 kg·m⁻³), and the N1W1 treatment had the highest PFP_N (170.87 kg·kg⁻¹). In summary, the moderate nitrogen application rate (120 kg·ha⁻¹) combined with mild water deficit (65–85% θ_f at the jointing stage) could not only promote the high yield of Bromus inermis, but also avoid the leaching of water and nitrogen in deep soil. It is a suitable water and nitrogen management mode for Bromus inermis in the Hexi Corridor of Gansu Province, China. Full article

(This article belongs to the Special Issue Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Soil Improvement and the Efficient Utilization of Water and Fertilizer in Greenhouse Crops

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (21 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI