Search Results (78)

Xinjiang, a key grain production region in arid Northwest China, faces severe water scarcity and low agricultural water use efficiency. Although subsurface drip irrigation (SDI) has been widely studied for horticultural crops, a comprehensive synthesis focusing on SDI system design, water–fertilizer management, and soil–crop responses in wheat production under arid conditions remains limited. This knowledge gap restricts the development of optimized irrigation strategies for wheat cultivation in Xinjiang, where extreme aridity, widespread oasis agriculture, soil salinization risk, and the dominance of densely planted wheat create management requirements that differ from those of humid regions and horticultural production systems. Therefore, this review summarizes the development of SDI technology, its system design parameters, and integrated water–fertilizer management strategies, while systematically integrating recent advances in soil–crop–microbial interactions and resource use efficiency under arid conditions, which have rarely been synthesized in previous SDI reviews. Synthesizing current knowledge on the impacts of SDI on soil water dynamics, soil properties, microbial communities, crop root architecture, biomass production, and resource use efficiency, this review further discusses general advances in SDI in the context of their relevance to Xinjiang, with particular emphasis on how regional soil–climate conditions and wheat production practices influence system design, fertigation management, and field applicability. Multiple studies indicate that SDI can simultaneously reduce evaporation and deep percolation, mitigate surface salt accumulation, promote deeper root development, and improve crop productivity and resource use efficiency. However, high initial investment and maintenance costs, along with risks of emitter clogging, still hinder its large-scale adoption. For Xinjiang’s wheat and other densely planted crops, future research should prioritize optimizing subsurface drip irrigation (SDI) systems, as studies have shown that SDI can increase water use efficiency (WUE) by 20–30% and enhance crop yield by 10–15%, particularly under water-scarce conditions. The study’s findings are as follows: (1) optimize SDI system parameters for local soil–climate conditions, (2) elucidate the synergistic mechanisms between water–fertilizer coupling and soil–crop systems, and (3) develop cost-effective and durable system components. Importantly, these findings are particularly relevant for Xinjiang, where extreme aridity, soil salinization, and limited water resources require region-specific optimization of SDI systems. These efforts will support efficient and sustainable wheat production in Xinjiang and other arid regions. Full article

Wildfires alter multiple soil functions in forest ecosystems, but how they reconfigure the linkages between these functions is not fully understood. We evaluated the 1-year-postfire and 11-year-postfire effects of wildfire on carbon sequestration, nutrient cycling, fertility maintenance, and erosion regulation, as well as their relationships, in a Chinese boreal larch forest. We further identified the environmental drivers regulating these associations. One year postfire, the soil fertility index transiently increased by 85%, whereas the carbon sequestration and nutrient cycling declined by 58% and 54%, respectively. Principal component analysis showed that wildfire decoupled the multivariate relationships between four soil functions. While these functions were closely clustered in unburned controls, they became dispersed one year postfire, indicating functional dissociation. After eleven years of recovery, a partial reassembly occurred, but with a reconfigured functional structure distinct from the pre-fire state. For the functional pairs, the impact of wildfire was limited to shifting the relationship between the soil fertility and nutrient cycling from a non-significant negative correlation to a significant positive correlation. Redundancy analysis showed that the soil water content remained the primary environmental driver of soil functional relationships before and after the fire, but its role reversed from negative in unburned stands to positive during the postfire recovery, suggesting a shift toward water-mediated functional coupling. Wildfires in boreal forests have far-reaching effects on soil ecosystems, including impacts on the relationships between various soil functions. Our results indicate that wildfire reconfigures the network of soil function linkages in boreal forests, with implications for the recovery of boreal soil ecosystems. Full article

Oil palm is an important economic crop that is widely cultivated, especially in Southeast Asia. Thailand is one of the world’s largest producers and exporters of palm oil. Efficient management of oil palm plantations is crucial for increasing yields and minimizing agricultural losses. This study aimed to develop a smart oil palm plantation and production management system. This system utilizes Internet of Things (IoT) technology and an integrated supervised machine learning model utilizing regression analysis to monitor and control agricultural equipment within the plantation. MySQL database was used for management of sensor data. Python (version 3.9.6) programming and Google Map API were used for data analysis, spatial analysis and data visualization suite in the system. The results showed that the data from the sensors are displayed in real-time, allowing plantation managers to monitor conditions remotely and make informed adjustments as needed. The system also includes data analysis and data visualization tools for decision-making regarding production management. The model attained an accuracy of over 95%, which reflects its reliability in performing the specified prediction task. The system serves as a support tool for automating soil quality monitoring, fertilization, and field maintenance in oil palm plantations. This enhances productivity, reduces operational costs, and improves yield planning. Full article

Sugar beet (Beta vulgaris L.) is an important economic crop and a primary source of sugar in northern China, characterized by strong stress tolerance and high nutritional value. Microbial inoculants can promote crop growth by regulating soil enzyme activities, enriching dominant beneficial bacterial genera in rhizosphere soil, and improving the availability of soil nutrients. This study aimed to investigate the role of microbial inoculants in sugar beet production and their potential to replace chemical fertilizers and put forward the scientific hypothesis that microbial inoculants can increase soil nutrients and improve the soil microenvironment. A two-year field experiment was conducted: in 2022, treatments with different application rates of Bacillus subtilis and Trichoderma spp. inoculants were set up to screen the optimal inoculant and its dosage (M1); in 2023, based on this optimal inoculant (M1), treatments with reduced chemical fertilizer input were established to explore the mechanisms underlying the maintenance of sugar beet yield and quality. The results showed that the M1N2 (75 kg/ha fertilizer and 20% less nitrogen fertilizer) treatment significantly increased nitrogen, phosphorus, and potassium agronomic use efficiencies by 91.48%, 51.94%, and 53.50%, respectively, compared with the control (CK). Soil urease, catalase, and sucrase activities were significantly enhanced by 14.57%, 66.84%, and 222.46%, respectively. The treatment also significantly increased the relative abundance of beneficial bacterial genera such as JG30-KF-CM45 and KD4-96, while sugar beet yield was significantly increased by 5.53% relative to the CK. This study provides a theoretical basis for the application of microbial inoculants and the reduction in chemical fertilizers in sugar beet production. Full article

Soil microbial nutrient limitation is of great significance for the maintenance of soil fertility, the sustainability of plant growth, and the stability of the alpine meadow ecosystems, which are particularly sensitive to global climate change. This study aimed to explore the effects of soil extracellular enzyme activities on soil microbial nutrient limitation across three altitudinal gradients—low altitude (LA: 2900–3200 m above sea level (masl)), middle altitude (MA: 3200–3500 masl), and high altitude (HA: 3500–3800 masl)—in alpine meadows in the northeastern Qinghai–Tibet Plateau, using the method of ecological stoichiometry. The research results showed that soil nutrients mostly accumulate in the surface layer: with increasing altitude, soil organic carbon (SOC) and total nitrogen (TN) contents gradually increase (p < 0.05), and their contents at high altitude in the 0–20 cm soil layer are twice those at low altitude. The activities of β-1,4-glucosidase (BG) and β-1,4-N-acetylglucosaminidase (NAG) at high altitude are significantly 26.77% and 30.88% higher than those at low altitude, respectively. Linear regression analysis shows a significant positive correlation between soil nutrients and C/N/P-related enzymes after logarithmic transformation along the altitudinal gradient. Enzyme vector analysis revealed that in the alpine meadows at altitudes ranging from 2900 to 3800 masl, relative nitrogen limitation was widespread, while relative carbon limitation was more significant in both high-altitude and low-altitude regions (p < 0.05). Notably, this study did not account for the granulometric composition of the soil at the sampling sites. Nevertheless, it partially reveals the nutrient acquisition strategies of microorganisms across different altitudinal gradients, providing a theoretical basis for understanding nutrient cycling in alpine meadow ecosystems and addressing global change. Full article

Soil microorganisms are important decomposers in soil, and they play important roles in litter degradation, nutrient cycle and balance, soil physicochemical property improvement, and soil fertility maintenance. To understand the influence of Eucalyptus plantations on the growth, reproduction, and activity of soil microorganisms in severely degraded land, the Leizhou Peninsula in tropical China was selected as the research area. The vegetation restoration types of Eucalyptus urophylla × grandis planted in its severely degraded red soil areas (ES: Eucalyptus–shrub, EG: Eucalyptus–grass, and ED: Eucalyptus–Dicranopteris pedata (Houtt.) Nakaike) were studied, and the nearby natural vegetation types (S: shrub, G: grass, and D: Dicranopteris pedata) served as control groups. The microbial characteristics of different vegetation restoration types were compared, and the influence of Eucalyptus plantations on the growth, reproduction, and activity of soil microorganisms in severely degraded red soil areas was discussed by setting up sample plots for investigation, sample determination, and statistical analysis. The structure of soil microorganisms differed significantly between Eucalyptus vegetation restoration (ER) and natural vegetation restoration without Eucalyptus (NER). Key organic decomposers, including bacterial genera such as Candidatus Solibacter (ER: 1.2 ± 0.4% vs. NER: 0.9 ± 0.1%), Candidatus Koribacter (ER: 1.0 ± 0.4% vs. NER: 0.7 ± 0.1%), and Edaphobacter (ER: 0.9 ± 0.1% vs. NER: 0.4 ± 0.1%), as well as fungal genera such as Rhizophagus (ER: 0.1 ± 0.0% vs. NER: 0.0 ± 0.0%), Paxillus (ER: 0.1 ± 0.0% vs. NER: 0.0 ± 0.0%), and Pisolithus (ER: 0.1 ± 0.0% vs. NER: 0.0 ± 0.0%), exhibited a significantly higher relative richness and a broader distribution in ER compared to NER (p < 0.05). Soil microbial biomass carbon, nitrogen and phosphorus (MBC, MBN, MBP), community structure (keystone taxa and symbiosis network complexity), and functional genes (for growth, reproduction, and decomposition) in ER, especially in ES, were significantly higher than in NER. This study illustrated that Eucalyptus plantations, especially ES types, can promote the growth and reproduction of soil organic decomposers, improve microbial metabolic and biological activities, and increase functional diversity and interactions among microorganisms, thus accelerating the cycle of soil carbon, nitrogen, and phosphorus nutrients, improving soil quality and fertility, and accelerating the recovery of degraded soil fertility. In areas with serious soil degradation and where natural vegetation restoration is difficult, planting Eucalyptus, especially while guiding the understory vegetation to develop into the shrub vegetation type, is an effective vegetation restoration model. Full article

Semi-natural grasslands are some of the most species-rich habitats in Europe and provide important ecosystem services such as biodiversity conservation, carbon sequestration and soil fertility maintenance. This study investigates how different intensities of grassland management affect the composition of functional groups and soil chemical properties. Five grassland management systems were analyzed: Cut3—three cuts per year; LGI—low grazing intensity; CG—combined cutting and grazing; Cut4—four cuts per year; and HGI—high grazing intensity. The functional groups assessed were grasses, legumes and forbs, while soil samples from three depths (0–10, 10–20 and 20–30 cm) were analyzed for their chemical properties (soil organic carbon—SOC; soil total nitrogen—STN; inorganic soil carbon—SIC; soil organic matter—SOM; potassium oxide—K₂O; phosphorus pentoxide—P₂O₅; C/N ratio; and pH) and physical properties (volumetric soil water content—VWC; bulk density—BD; and porosity—POR). The results showed that less intensive systems had a higher proportion of legumes, while species diversity, as measured via the Shannon index, was the highest in the Cut4 system. The CG system tended to have the highest SOC and STN at a 0–10 cm depth, with a similar trend observed for SOC_stock at a 0–30 cm depth. The Cut4, HGI and CG systems also had an increased STN_stock. Both grazing systems had the highest P₂O₅ content. A tendency towards a higher BD was observed in the top 10 cm of soil in the more intensive systems. Choosing a management strategy that is tailored to local climate and site conditions is crucial for maintaining grassland stability, enhancing carbon sequestration and promoting long-term sustainability in the context of climate change. Full article

Forest shelterbelts and windbreaks play a vital role in protecting ecosystems, mitigating climate change effects, and enhancing agricultural productivity. These vegetative barriers serve as effective tools for soil conservation, reducing wind and water erosion while improving soil fertility. Additionally, they contribute to biodiversity preservation by providing habitat corridors for various plant and animal species. Their role in microclimate regulation, such as temperature moderation and increased humidity retention, further enhances agricultural yields and ecosystem stability. This study examines the historical evolution, design principles, and contemporary applications of forest shelterbelts and windbreaks, drawing insights from scientific research and case studies worldwide. It highlights the economic and environmental benefits, including improved air quality, carbon sequestration, and water management, making them crucial components of sustainable land use strategies. However, challenges such as land use competition, maintenance costs, and policy constraints are also analyzed, underscoring the need for integrated approaches to their management. Through a comprehensive bibliometric analysis of the existing literature and field studies, this paper emphasizes the necessity of strategic planning, community involvement, and adaptive policies to ensure the long-term sustainability of forest shelterbelts and windbreaks. The findings contribute to a broader understanding of their role in combating environmental degradation and promoting ecological resilience in the face of ongoing climate challenges. Full article

This study assesses the current status of selected soil properties of an expanding equatorial agricultural region (Arauca, Colombia) across six landscapes, with the final focus being on evaluating overall soil quality. Field surveys, morphological descriptions, and laboratory analyses of 133 soil profiles were investigated. The landscapes include mountains (25 profiles), foothills (17), hills (11), alluvial plains (43), alluvial plains with dunes (21), and alluvial valleys (16). Soils are classified into six Reference Soil Groups (WRB FAO): Gleysols, Acrisols, Arenosols, Ferralsols, Leptosols, and Cambisols. The findings indicate high acidity, low fertility, and deficient exchangeable bases. Indeed, pH ranges from extremely acid to slightly acid (3.5–6.4), and exchangeable acidity saturation percentage (%SAI) values reach 100% in some areas. Soil textures vary from clay loam to sandy loam and clay. Nutrient contents are ranked in the order Cambisols > Gleysols > Arenosols > Ferralsols > Acrisols > Leptosols. Correlation analysis reveals that clay content positively influences the exchangeable basis percentage, while organic matter (OM) negatively correlates with the nutrients phosphorus, calcium, and magnesium. This study highlights that landscape position influences soil quality, with lower landscape positions having better quality than upper ones. These results provide insights into soil fertility and nutrient availability, which helps to predict suitable plant cultivation areas when increasing areas for agricultural use versus forestry in Arauca. The inclusion or maintenance of diverse tree species is a key element in maintaining the production of organic matter and, consequently, generating better soil quality. Full article

The main challenge of soybean cultivation in Brazil’s last agricultural frontier is to ensure sustainable production. This study aimed to evaluate the use of cover crops (CC) to improve soil fertility, plant nutrition, and soybeans productivity grown in the Cerrado of Brazil. The study was carried out on a farm located in the state of Maranhão, Brazil, with nine treatments, fallow and CC preceding soybean cultivation: (i) Millet (Pennisetum glaucum L.); (ii) Marandu (Urochloa brizantha); (iii) Ruziziensis (Urochloa ruziziensi); (iv) Tanzania (Megathyrsus maximum); (v) Massai (Megathyrsus maximum); (vi) cowpea (Vigna unguiculata L.); (vii) pigeon pea (Cajanus cajan L.); and (viii) Crotalaria (Crotalaria juncea). An analysis for the characterization of the biomass of cover crops and fallow was carried out. Soil chemical and biological properties, soybean foliar nutrient concentrations, and the soybean seed yield and quality grown in sequence to the CC were also analyzed. Soil microbial carbon was favored by the cultivation of ‘Marandu’, ‘Ruziziensis’, ‘Tanzania’, and cowpea. Nutrient cycling promoted by CC contributed to the maintenance of soil quality and increases in the leaf nutrient concentrations of soybeans. The cultivation of millet, ‘Tanzania’, ‘Massai’, cowpea, and C. juncea increased the soybean yield. Cover crops improved soil fertility while increasing soybean productivity, thus being an effective strategy for the achievement of sustainable soybean production. Full article

Forests can simultaneously provide a variety of ecosystem functions and services (ecosystem multifunctionality, EMF). Different stand types, influenced by biotic and abiotic factors, play a key role in determining EMF. To clarify the impact of stand type, as well as biotic and abiotic factors, on EMF, this study quantified EMF across three stand types: Betula platyphylla pure forest (BP), B. platyphylla–Larix principis-rupprechtii mixed forest (BL), and L. principis-rupprechtii pure forest (LP). The multiple-threshold approach was employed to quantify EMF, while structural equation modeling was used to analyze the primary factors influencing EMF. The results indicated the following: (1) BL had higher stand productivity than both BP and LP; (2) BL exhibited significantly higher functional diversity and soil fertility maintenance compared to LP, with no significant difference between BP and BL; (3) BP demonstrated a significantly stronger nutrient cycling function than LP, with no significant difference between LP and BL; (4) the ranking of EMF at all threshold levels was BL > BP > LP; (5) soil was an effective driver of EMF across all threshold levels; and (6) both the niche complementarity effect and the mass ratio effect jointly drove EMF at the low threshold (<50%), with the influence of both effects diminishing as the threshold increased. This study enhances our understanding of the key drivers of EMF in forest ecosystems and provides valuable insights for informing multifunctional forest management practices. Full article

It is well established that root exudates play a crucial role in shaping the assembly of plant rhizosphere microbial communities. Nonetheless, our understanding of how different types of exudates influence the abundance of potential pathogens in soil remains insufficient. Investigating the effects of root exudates on soil-dwelling pathogenic fungi is imperative for a comprehensive understanding of plant–fungal interactions within soil ecosystems and for maintaining soil health. This study aimed to elucidate the effects of the principal components of root exudates—flavonoids (FLA), phenolic acids (PA), and organic acids (OA)—on soil microbial communities and soil properties, as well as to investigate their mechanisms of action on soil potential pathogenic fungi. The results demonstrated that the addition of these components significantly modified the composition and diversity of soil microbial communities, with OA treatment notably altering the composition of dominant microbial taxa. Furthermore, the introduction of these substances facilitated the proliferation of saprophytic fungi. Additionally, the incorporation of flavonoids, phenolic acids, and organic acids led to an increased abundance of potential pathogenic fungi in the soil, particularly in the FLA and PA treatments. It was observed that the addition of these substances enhanced soil fertility, pH, and antioxidant enzyme activity. Specifically, FLA and PA treatments reduced the abundance of dominant microbial taxa, whereas OA treatment altered the composition of these taxa. These findings suggest that the inclusion of flavonoids, phenolic acids, and organic acids could potentially augment the enrichment of soil potential pathogenic fungi by modulating soil properties and enzymatic activities. These results offer valuable insights into the interactions between plants and fungal communities in soil ecosystems and provide a scientific foundation for the management and maintenance of soil health. Full article

Tongzhou District is designated as a city sub-center with 33.3% forest cover, representing significant ecological value for Beijing. However, this extensive forest area has lacked detailed conservation measures, leading to inefficient resource utilization over the years. Therefore, determining the various maintenance measures for the different areas is very important. This study focused on exploring the relationship between the soil nutrient structure and vegetation indices in the area to develop a more precise plan for forest maintenance. This study collected 163 sample points in the four zones of Tongzhou district, including electrical conductivity, acidity and alkalinity, bulk density, soil organic matter, total nitrogen, available nitrogen, total phosphorus, total potassium, available potassium, available phosphorus, as well as vegetation characteristics such as richness, coverage, and height. The normalized difference vegetation index, difference vegetation index, ratio vegetation index, green light vegetation index, and soil-adjusted vegetation index were calculated by remote sensing images. To test the spatial distribution of soil nutrient construction and the relationship between soil and vegetation indices using the spatial interpolation method and Pearson correlation analysis, the results showed that: (1) The soil organic matter and total nitrogen were extremely low (1.282 and 0.461 g/kg). In contrast, the available and total potassium was extremely high (227.994 mg/kg and 16.866 g/kg); (2) High-value areas of available and total potassium are in the northern area, the available and total phosphorus in the central area, and the pH in the northeast area, with overall neutral-to-alkaline conditions; (3) The mean of coverage is 72.120, with high-value areas concentrated in northern parts of the central areas. While the overall coverage is extensive, height varies significantly (3.300–479.867), and high-density vegetation is limited to the northern part of the central area; (4) Vegetation height shows a significant negative correlation with total potassium and a significant positive correlation with pH values. We suggest that it is necessary to properly retain fallen leaves and dead grass in the forest to increase the organic matter content of the soil, apply more organic fertilizers, and supplement nitrogen fertilizers. In Tongzhou District, potassium fertilizer application should be reduced, particularly in the northeast and northern areas, to prevent excess fertility. In the central area, phosphorus fertilizer application should also be controlled, while in alkaline areas, fertilizer use should be optimized, and lime should be added to improve pH. Compost or humic acid can improve the soil’s ability to absorb and release phosphorus, thereby enhancing plant phosphorus uptake and increasing vegetation height and coverage. This study only analyzed spatial changes without further examining soil layer differences at varying depths and the effects of soil microorganisms. In the future, soil fertility in various depths and the functionality and diversity of soil microorganisms are worth further exploring. Full article

Crop production is heavily dependent on fertilizers that negatively impact the environment; therefore, research on biochar to improve the soil’s properties and reduce greenhouse gas emissions has intensified over the years. To elucidate rice yield and greenhouse gas emission (GHG) arising from the application of biochar and N fertilizer on paddy soil in Northeast China, a 3-year (2015–2017) field experiment was established. Adopting a split-plot design with three replicates, two nitrogen (N) fertilizer levels in the main plots were designated as follows: 120 kg N ha⁻¹ (N1, 2/3 of N application rate for optimal local rice yield); 180 kg N ha⁻¹ (N2, full N application rate for optimal local rice yield); and four biochar application rates of no biochar (C0, control); 1.0 t ha⁻¹ biochar (C1); 1.5 t ha⁻¹ biochar (C2); and 2.0 t ha⁻¹ biochar (C3) were designated as sub-treatments. The results showed that in 2015, biochar amendment increased GHG emissions while between 2016 and 2017, biochar amendment of 1.5 t ha⁻¹ decreased CH₄ emissions, global warming potential (GWP), and greenhouse gasses intensity (GHGI) by 11.3%, 10.9%, and 17.0%, respectively. On average, for the years 2016 and 2017, the N₂O fluxes were 17.0% lower in the N2 plots compared to the N1 plots. Biochar amendment of 1.5 t ha⁻¹ recorded an 8.6% increase in rice yield compared to the control. The soil properties of the study site showed that biochar amendment of 1, 1.5, and 2 t ha⁻¹ augmented soil organic matter by 3.3%, 5.3%, and 5.2%, respectively, and soil phosphorus availability by 6.4%, 11.2%, and 22.6%, respectively. The co-application of biochar at 1.5 t ha⁻¹ and 180 kg N ha⁻¹ effectively regulated GHG emissions while maintaining crop yield. Appropriate co-application of biochar with N fertilizer can be adopted for emission reduction and rice yield maintenance while maintaining soil fertility in Northeast China. Full article

The issue of soil contamination by heavy metals (HMs) has attracted extensive attention. In the present study, the effects of four remediation measures combined with rice intercropping on the quality of soils were evaluated in a mildly HM-contaminated paddy field. The results showed that better comprehensive remediation effects were found in the intercropping system with high and low Cd-tolerant rice than in the monoculture system. Both foliar spraying of sodium selenite and inoculation with Pseudomonas TCd-1 significantly reduced the Nemerow comprehensive pollution index (NCPI) of the soils. The application of biochar and lime significantly increased the soil fertility index. Among all the treatments, the application of 30 t∙hm⁻² biochar and 3600 kg∙hm⁻² lime improved soil fertility the most. The lowest single-factor pollution indices (SFPIs) of Cd, Cu, Zn, Ni and Pb and the NCPI of the soils were observed in the treatment with foliar spraying of sodium selenite at 45 mg∙L⁻¹, showing the greatest comprehensive reduction in soil HMs. The application of 1200 kg∙hm⁻² lime and 30 t∙hm⁻² biochar and foliar spraying of 45 mg∙L⁻¹ sodium selenite effectively improved the soil quality. Overall, the soil quality of paddy fields dramatically influenced the cleaner production of rice and is of great significance to the maintenance of food security. Full article