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In a nine-year field experiment in a wheat-maize-sunflower cropping system in Hetao Irrigation Area, Inner Mongolia, China, organic amendments applied as straw, manure, green manure, and the combination of green manure and straw increased wheat and maize yield, soil aggregate stability, and soil microbial activity in comparison with chemical fertilizer, without changing greenhouse gas emission intensity. [ABSTRACT FROM AUTHOR]

Assessments of farmer satisfaction can be a crucial tool for effectively implementing an appropriate ecological compensation policy. This study evaluates the effectiveness of an ecological compensation policy for crop rotation in China's black soil regions from the perspective of farmer satisfaction. Specifically, utilizing an improved entropy TOPSIS, logistic regression, and the obstacle degree model, this empirical study analyzes the performance of the ecological compensation policy for crop rotation in black soil regions and identifies barriers in Heilongjiang Province. The findings indicate that gender significantly and positively affects outcomes at the 10% level, while age has a notable influence at the 5% level. Additionally, the family labor force and the quality of cultivated land, both significant at the 5% level with negative coefficients, suggest a diminished likelihood of farmers participating in these ecological compensation projects. The family's source of income, significantly influential at the 1% level, also indicates a lower propensity among farmers to engage. Performance analysis reveals that the values for variables of satisfaction with the project's publicity (A1), satisfaction with the protection of farmers' rights and interest (A3), overall satisfaction with the effectiveness of the project (B1), satisfaction with ecological compensation methods (B3), and satisfaction with household income after the implementation of the project (C1) are above the average. In contrast, values for variables of satisfaction with the supervision and management (A2), satisfaction with the payment of ecological compensation funds (A4), satisfaction level with black soil rotation ecological compensation standards (B2), satisfaction with the welfare level of family life after the implementation of the project (C2), and satisfaction with farmers' proactive participation in the project (D1) fall below the average of 3.03. Therefore, this study provides a comprehensive framework for assessing the effectiveness of the ecological compensation policy for crop rotation in China's black soil regions and offers recommendations for enhancing its performance. [ABSTRACT FROM AUTHOR]

Background: Guangxi is the leading sugarcane-producing area in China. Due to the Panama disease outbreak in banana gardens, sugarcane and banana rotation was recommended. A field experiment with the newly released sugarcane cultivar Zhongzhe 1 (ZZ1) was conducted to understand the role of the sugarcane–banana rotation system in shaping the rhizosphere microbiota. Fields in the region possess characteristics of red laterite soil. Results: Using Illumina HiSeq sequencing to analyze soil samples' 16S rRNA V3-V4 region, the preceding banana rotation field had relatively greater bacterial diversity than the monoculture sugarcane field. Proteobacteria, Chloroflexi, Actinobacteria, and Acidobacteria were the dominant phyla, with distinct taxa enriched in each environment. However, the preceding sugarcane monoculture field enriched functional groups related to nitrogen fixation and cellulolysis. Network analysis highlighted contrasting network structures between sugarcane and banana rhizospheres, suggesting differential stability and susceptibility to environmental influences. Furthermore, correlations between soil properties and bacterial alpha-diversity underscored the influence of preceding crops on rhizosphere microbial communities. Conclusion: This research enhances our understanding of crop rotation effects on soil microbial ecology and provides insights into optimizing agricultural practices for enhanced soil health and crop productivity. Future studies should explore the underlying mechanisms driving these interactions and evaluate the long-term impacts of crop rotation on soil microbial dynamics. [ABSTRACT FROM AUTHOR]

Codonopsis pilosula (Franch.) Nannf. is an essential traditional medicinal herb in China. Soil sickness caused by continuous cropping is the main reason for the yield reduction of C. pilosula. However, because of the lack of systematic research on the mechanism of continuous cropping obstacles in C. pilosula, there is a lack of effective measures to reduce or even restrain the disorder of continuous cropping obstacles in C. pilosula. The root system, inter‐root soil microorganisms and non‐inter‐root soil of C. pilosula under a continuous cropping system (e.g. crop rotation, two consecutive crops and three consecutive crops) as well as under different mulching methods (the mulched film and the uncovered) were used as experimental materials for the study. The plant growth of C. pilosula was significantly inhibited when continuous cropping reached 2 years. At the same time, the mulched film significantly (p <.05) promoted the development of C. pilosula under continuous cropping and considerably mitigated the plant death rate of C. pilosula in all fields. The content of soil nutrients, such as organic matter and inorganic nitrogen, decreased with increasing years of continuous cropping. In contrast, the mulched film improved this soil nutrient in continuous cropping. There was a tendency for the number of endemic operational taxonomic units (OTUs) to decrease in continuous cropping. Additionally, the mulched film altered the distribution of shared and endemic OTUs in the samples and had a recruiting effect on inter‐root microorganisms in continuous cropping. Betaproteobacteriales flora abundance decreased with increasing years of continuous cropping, which showed a strong positive correlation with the immune system and environmental adaptation function. The mulched film increased the abundance of beneficial microorganisms, such as AKAU4049, Betaproteobacteriales and Gaiellales, to adapt and improve the continuous crop disorder of C. pilosula. In conclusion, mulching can enhance the soil environment and facilitate the growth and development of C. pilosula during continuous cultivation. [ABSTRACT FROM AUTHOR]

Assessment of agricultural water requirements under future climate projections has received increasing attention in recent decades. The agriculture pattern of the semi-arid North China Plain is a maize–wheat rotation system in which sufficient irrigation is required to maintain production. In this study, the effects of future climate scenarios on the net irrigation requirement of the maize–wheat rotation system were assessed using the Food and Agriculture Organization crop growth model—AquaCrop. First, the baseline net irrigation requirement over the study region was obtained through AquaCrop simulation under ERA5-Land reanalysis from 2011 to 2020. In addition, the AquaCrop model was used to predict irrigation requirements in future scenarios (2021–2050) under the extreme-emission scenario of the Shared Socioeconomic Pathway SSP 5-8.5 (SSP 5-8.5). Finally, the predicted irrigation amount for maize and wheat during the period 2021–2050 under SSP 5-8.5 was compared with the baseline to assess the interannual change in irrigation water requirement. Results reveal significant agreement between the AquaCrop-derived daily soil moisture (SM) and a reference SM product with unbiased root mean square differences of 0.03 m3/m3 and 0.04 m3/m3 over maize and wheat, respectively. Furthermore, the median net irrigation requirement is expected to increase by approximately 107 mm (21%) to guarantee optimum yield. [ABSTRACT FROM AUTHOR]

Leguminous green manure (LGM) has a reputation for improving crop productivity. However, little is known about the beneficial interactions with straw on crop yield and nutrient (N, P, K) use efficiency. Herein, a 9-year field experiment (from 2015 to 2023) containing three treatments—(1) chemical fertilizer as the control (CK), (2) NPK + straw return (Straw) and (3) NPK + straw return with LGM (Straw + LGM)—was conducted to investigate whether the combined application of LGM and straw can increase productivity and nutrient use efficiency in the wheat–maize–sunflower diversified cropping rotation. The results showed that in the third rotation (2021–2023), Straw + LGM significantly increased wheat yield by 10.2% and maize yield by 19.9% compared to CK. The total equivalent yield under Straw + LGM was the highest (26.09 Mg ha−1), exceeding Straw and CK treatments by 2.7% and 12.3%, respectively. For each 2 Mg ha−1 increase in straw returned to the field, sunflower yield increased by 0.2 Mg ha−1, whereas for each 1 Mg ha−1 increase in LGM yield from the previous crop, sunflower yield increased by 0.45 Mg ha−1. Compared to CK, the co-application of LGM and straw increased the N use efficiency of maize in the first and third rotation cycle by 70.6% and 55.8%, respectively, and the P use efficiency by 147.8% in the third rotation cycle. Moreover, Straw treatment led to an increase of net income from wheat and sunflower by 14.5% and 44.6%, while Straw + LGM increased the net income from maize by 15.8% in the third rotation cycle. Combining leguminous green manure with a diversified cropping rotation has greater potential to improve nutrient use efficiency, crop productivity and net income, which can be recommended as a sustainable agronomic practice in the Hetao District, Northwest China. [ABSTRACT FROM AUTHOR]

Vegetable production in Subtropical China is distinguished by excessive nitrogen (N) fertilization, frequent irrigation, and multiple crop rotations in a single year. The aforementioned variables are closely related to soil nitrous oxide (N2O) and methane (CH4) emissions. Hence, we conducted a field trial to measure N2O and CH4 emissions using static chamber–gas chromatograph. Four treatments were used: control (CK) with no fertilizer, 100% chemical N fertilization (CN), the conventional 30% chicken manure N plus 70%CN (CMN + CN), and 30% chicken manure biochar N plus 70%CN (CMBN + CN). The annual cumulative N2O emissions reached 12.4, 63.5, 111.8, and 44.1 kg N2O-N ha−1 for the CK, CN, CMN + CN, and CMBN + CN treatments, respectively. Compared to the CN and CMN + CN treatments, the CMBN + CN treatment reduced N2O emissions by 35.9%–65.7%, while it simultaneously increased the total vegetable yield by 16.1% compared to the CN treatment. Seven seasons mean N2O emission factors are 1.3% for CN, 3.8% for CMN + CN, and 0.9% for CMBN + CN. The CH4 emission was negligible, ranging from 0.07 kg CH4-C ha−1 for the CK treatment to 0.8 kg CH4-C ha−1 for the CN treatment. N2O emissions peaked under the conditions of an interior chamber temperature of around 31.9 °C and the water-filled pore space (WFPS) of the soil being approximately 60%. Future climate change will intensify, triggering higher N2O emissions from subtropical vegetable fields. CMB can be one of the best substitutes for direct chicken manure application as a soil supplement because it has a beneficial effect on improving vegetable yield and reducing N2O emissions in Subtropical China. [ABSTRACT FROM AUTHOR]

Achieving high stable crop yields and minimal environmental damage is crucial to enhance the sustainability of agriculture in China. Process‐based models are indispensable tools to develop agronomy management practices to achieve sustainable agriculture by simulating crop production and emissions of reactive nitrogen (N), particularly in complex climate scenarios. In this study, a long‐term field experiment with an intensive summer maize‐winter wheat rotation system in north‐central China was simulated using the DeNitrification‐DeComposition (DNDC) model. The DNDC model validation and calibration was done by using two‐year monitoring data of crop yields and nitrous oxide emission fluxes and ammonia volatilization. Moreover, the optimal management practices to promote crop production and reduce the reactive N loss under 22 years of climate variability were explored using the calibrated DNDC model in this region. The results showed that the DNDC model effectively simulated wheat and maize yields, N uptake, ammonia volatilization, and nitrous oxide emissions. Sensitivity analyses demonstrated that the agronomic management practices (N rates and ratio of base to topdressing, planting time, and tillage depth) substantially affected crop yields and reactive N losses under long‐term climate variability. Compared with current farming practices, optimal Nutrient Expert (NE) management achieved an increase in high yields and environmental pollution radiation by altering the rate of N application and ratio of base to topdressing. Moreover, the optimal management strategies developed by the DNDC model, such as adjusting the planting date and tillage depth, further increased the average grain yield by 2.9% and reduced the average reactive N losses by 10.5% compared with the NE management implemented in the annual rotation cropping with a 22‐year simulation. This study suggests that the modeling method facilitates the development of most effective agronomic management practices to promote crop production and alleviate the negative impact on environment. [ABSTRACT FROM AUTHOR]

Straw return utilizes waste resources to reduce the use of chemical fertilizers worldwide. However, information is still lacking on the relative impact of straw return on soil fertility, the nutrient composition of different soil aggregates, and soil microbial communities. Therefore, this study aimed to understand the effects of different management practices on the crop yield, soil fertility, and soil community composition in a 14-year wheat–rice rotation system. The treatments included a control (without fertilizer and straw addition), chemical fertilization (NPK), straw return without fertilizer (S), and straw addition with chemical fertilizer (NPKS). The results showed that NPKS improved the wheat and rice yield by 185.12% and 88.02%, respectively, compared to the CK treatment. Additionally, compared to the CK treatment, the N, P, and K contents of the wheat stem were increased by 39.02%, 125%, and 20.23% under the NPKS treatment. Compared to the CK treatment, SOM, TN, TP, AN, AP, AK, CEC, AFe, AMn, ACu, and AZn were increased by 49.12%, 32.62%, 35.06%, 22.89%, 129.36%, 48.34%, 13.40%, 133.95%, 58.98%, 18.26% and 33.33% under the NPKS treatment, respectively. Moreover, straw addition promoted the creation and stabilization of macro-aggregates in crop soils. The relative abundance of macro-aggregates (0.25–2 mm) increased from 37.49% to 52.97%. Straw addition was associated with a higher proportion of aromatic and carbonyl carbon groups in the soil, which, in turn, promoted the formation of macro-aggregates. Redundancy analysis showed that straw return significantly increased the microbial community diversity. These findings demonstrate that straw addition together with chemical fertilizer could increase the crop yield by improving soil fertility, soil aggregate stability, and the diversity of fungi. [ABSTRACT FROM AUTHOR]

Continuous cropping has a negative effect on soybean yield. In this study, a positioning experiment was conducted starting in 2015, with three treatments: maize–soybean rotation (SMR), 2-year maize, 2-year soybean rotation cropping (SC2), and 8-year soybean continuous cropping (SC8). We determined soybean yields (2015–2022) and analyzed soil microbial communities, functions, and metabolites composition in the 0–20 cm tillage layer using metagenomics technology and GC–MS technology during soybean flowering in 2022. Results indicated that continuous cropping (SC8) significantly reduced soybean yield compared to crop rotation (SMR) during the experimental period, while SC8 showed higher yield than SC2 in 2022. Compared to SMR, SC8 significantly increased soil N content and significantly decreased pH and TP, AP, and AK content. However, the pH and AK contents of SC8 were significantly higher than those of SC2. LeFSe analysis showed that Friedmanniella, Microlunatus, Nitrososphaera, Rubrobacter, Geodermatophilus, Nitriliruptor were enriched in SC8. Gaiella, Sphaerobacter, Methyloceanibacter were enriched in SC2. Sphingomonas, Cryobacterium, Marmoricola, Haliangium, Arthrobacter, Ramlibacter, Rhizobacter, Pseudolabrys, Methylibium, Variovorax were enriched in SMR. And the relative abundance of Cryobacterium, Marmoricola, Haliangium, Arthrobacter, Ramlibacter, Rhizobacter, Methylibium, Variovorax was significantly positively correlated with yield, while the relative abundance of Gaiella and Sphaerobacter was significantly negatively correlated with yield. SC8 significantly increased the abundance of genes in nitrogen metabolism and significantly decreased the abundance of genes related to phosphorus and potassium metabolism compared with SMR. However, the abundance of genes in potassium metabolism was significantly higher in SC8 than in SC2. Metabolomic analysis showed that compared to SMR, SC8 decreased the abundance of carbohydrates, ketones, and lipid. However, the abundance of carbohydrates, ketones, and lipid was significantly higher in SC8 than in SC2. Mantel test showed that soil pH and AK significantly affected soil microbial community, function, and metabolite composition. Correlation analysis showed significant correlation between soil metabolites and microorganisms, metabolic functions. [ABSTRACT FROM AUTHOR]

Under the carbon emission pattern of "peak carbon and carbon neutrality", the policy of crop rotation and fallow system (CRFS) is regarded as an important initiative to promote the green, low-carbon, and high-quality development of agriculture. Focusing on balanced panel data from 30 provinces in China from 2010 to 2021, this paper empirically examines the impact of CRFS on agricultural carbon emissions (ACEI) and its internal mechanism using a multi-temporal difference-in-differences model. The benchmark regression results show that CRFS can significantly reduce ACEI, and the results remain robust after validation by multiple methods. Mechanism results show that CRFS is able to reduce ACEI by reducing factor mismatch and promoting the level of agricultural services. Heterogeneity analysis results show that the arable land fallow rotation system is more conducive to promoting the reduction in agricultural carbon emission intensity in the main grain producing areas, main grain marketing areas, high land transfer areas, and plantation areas than in the grain production and marketing balanced areas, low land transfer, and animal husbandry areas. This study demonstrates the effectiveness of the CRFS policy implementation, provides a doctrinal basis for expanding the scope of CRFS implementation, and provides policy recommendations for relevant departments to improve the CRFS policy. [ABSTRACT FROM AUTHOR]

Climate is the most important environmental factor influencing yield during rice growth and development. To investigate the relationships between climate and yield under different crop rotation patterns and planting methods, three typical rotation patterns (vegetable–rice (V), rape–rice (R), and wheat–rice (W)) and two mechanical planting methods (mechanical transplanting (T1) and mechanical direct seeding (T2)) were established. The results showed that compared to the V rotation pattern, the average daily temperature (ADT) during the sowing to heading stage increased under both R and W rotation patterns, which significantly shortened the growth period. Thus, the effective accumulated temperature (EAT), photosynthetic capacity, effective panicle (EP), and spikelet per panicle (SP) under R and W rotation patterns significantly decreased, leading to reductions in grain yield (GY). VT2 had a higher ratio of productive tillers (RPT), relative chlorophyll content (SPAD), leaf area index (LAI), and net photosynthetic rate (Pn) than those of VT1, which significantly increased panicle dry matter accumulation (DMA), resulting in an increase in GY. Although RT2 and WT2 had a higher RPT than those of RT1 and WT1, the GY of RT1 and WT1 decreased due to the significant reductions in EAT and photosynthetic capacity. Principal component analysis (PCA) showed that the comprehensive score for different rotation patterns followed the order of V > R > T with VT2 ranking first. The structural equation model (SEM) showed that EAT and ADT were the most important climate factors affecting yield, with total effects of 0.520 and −0.446, respectively. In conclusion, mechanical direct seeding under vegetable–rice rotation pattern and mechanical transplanting under rape–rice or wheat–rice rotation pattern were the rice-planting methods that optimized the climate resources in southwest China. [ABSTRACT FROM AUTHOR]

Herbicide residues in farmland soils have attracted a great deal of attention in recent decades. Their accumulation potentially decreases the activity of microbes and related enzymes, as well as disturbs the nitrogen cycle in farmland soils. In previous studies, the influence of natural factors or nitrogen fertilization on the soil nitrogen cycle have frequently been examined, but the role of herbicides has been ignored. This study was conducted to examine the effects of herbicides on NH3 volatilization- and denitrification-related nitrogen loss through three rotation cycles from 2013 to 2016. The four treatments included no urea fertilizer (CK), urea (CN), urea+acetochlor-fenoxaprop-ethyl (AC-FE), and urea+2,4D-dicamba (2,4D-DI) approaches. The results showed that the application of nitrogen fertilizer significantly increased the nitrogen losses from ammonia volatilization and denitrification in the soil. Ammonia volatilization was the main reason for the gaseous loss of urea nitrogen in a wheat–maize rotation system in the North China Plain (NCP), which was significantly higher than the denitrification loss. In the CK treatment, the cumulative nitrogen losses from ammonia volatilization and denitrification during the three crop rotation cycles were 66.64 kg N hm−2 and 8.07 kg N hm−2, respectively. Compared with CK, the nitrogen losses from ammonia volatilization and denitrification under the CN treatment increased 52.62% and 152.88%, respectively. The application of AC-FE and 2,4D-DI significantly reduced the nitrogen gas losses from the ammonia volatilization and denitrification in the soil. Ammonia volatilization reduction mainly occurred during the maize season, and the inhibition rates of AC-FE and 2,4D-DI were 7.72% and 11.80%, respectively, when compared with CN. From the perspective of the entire wheat–maize rotation cycle, the inhibition rates were 5.41% and 7.23% over three years, respectively. Denitrification reduction also mainly occurred in the maize season, with the inhibition rates of AC-FE and 2,4D-DI being 34.12% and 30.94%, respectively, when compared with CN. From the perspective of the entire wheat–maize rotation cycle, the inhibition rates were 28.39% and 28.58% over three years, respectively. Overall, this study demonstrates that herbicides could impact the nitrogen cycle of farmland soil ecosystems via the suppression of ammonia volatilization and denitrification rates, thus reducing gaseous N losses and mitigating global climate change. [ABSTRACT FROM AUTHOR]

Various crop rotation patterns can result in differences in nutrient consumption and the accumulation of toxic substances in the soil, indirectly impacting the soil environment and its nutrient supply capacity. Implementing optimized crop planting practices is beneficial for maintaining the favorable physical and chemical properties of farmland soil in the arid area of northwestern China. This study aimed to establish a crop rotation pattern to improve key enzyme activities and soil nitrogen conversion efficiency, as well as understand the underlying mechanism for enhancing nitrogen supply capacity. A field experiment was conducted to study the effect of four flax planting patterns, which included 13 crop rotation patterns with different crop frequencies: 100% Flax (Cont F), 50% Flax (I) (WFPF, FPFW, PFWF, FWFP), 50% Flax (II) (FWPF, WPFF, PFFW, FFWP), 25% Flax (WPWF, PWFW, WFWP, FWPW), on the key enzyme activities and the rate of soil nitrogen conversion, as well as the nitrogen supply capacity. Here, F, P, and W represent oilseed flax, potato, and wheat, respectively. The results indicated that the wheat stubble significantly increased the intensity of soil ammonification and denitrification before planting. Additionally, the activity levels of soil nitrate reductase and nitrite reductase under wheat stubble were significantly increased by 66.67% to 104.55%, while soil urease activity significantly decreased by 27.27–133.33% under wheat stubble compared to other stubbles. After harvest, the activities of soil nitrate reductase and nitrite reductase under the wheat stubble decreased significantly, and the intensity of soil ammonification, nitrification, and denitrification reduced significantly by 7.83–27.72%. The WFWP and FWFP treatments led to a significant increase in soil nitrogen fixation intensity under various crop rotations after harvest and significantly increased the levels of inorganic nitrogen in the soil before the planting of the next crop. This study suggests that the long-term rotation planting patterns WFWP and FWFP can significantly enhance the key enzyme activities of soil nitrogen conversion and significantly improve soil nitrogen conversion before crop sowing. This may increase the rate of soil nitrogen transfer and raise the available nitrogen content of the soil. These findings are crucial for reducing soil nitrogen loss and improving soil nitrogen nutrient supply capacity in dry areas of the Loess Plateau of China. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Long-term large inputs of phosphorus (P) fertilizer in China have caused serious soil P accumulation, low P use efficiency (PUE) and high risk of P loss. Controlling the amount of P fertilizer applied presents an inevitable choice for improving the PUE. Struvite recycled from agricultural wastewater rich in N and P concentrations are capable of slow nutrient release, improving nutrient uptake and enabling the reuse of nutrients from environmental sources when applied to agricultural land. A two-year field experiment was conducted to investigate the effects of struvite combined with P reduction under a rice–wheat rotation system in eastern China. A total of five treatments were set up, including conventional fertilization (FP), a struvite substitution of 100% P fertilizer (SP), a 50% P reduction with struvite substitution (RSP), no application of N fertilizer (N0) and no application of P fertilizer (P0). Grain yield, crop N and P uptake, N and P use efficiency (NUE and PUE) and soil nutrient status were assessed. Under the same P application rate, the yield and aboveground biomass of the SP treatment were slightly higher than those of FP treatment, but the crop P uptake, PUE and soil available P content were significantly increased. The RSP treatment did not reduce yield with 50% P reduction, and significantly improved the PUE and soil available P content. Crop N uptake and NUE were also found to be increased in SP and RSP treatments with struvite substitution. The P apparent balance showed that both the SP and FP treatments had a P surplus, but the RSP treatment had a P break-even, and the soil available P content remains stable compared with the initial value. The results indicate that struvite application could improve the soil P availability and crop nutrient uptake then promote the crop yield. To increase the nutrient use efficiency of crops while ensuring crop yield and soil fertility, appropriate P reduction combined with struvite as a P fertilizer could be sustainable in the rice–wheat rotation system in the long run. [ABSTRACT FROM AUTHOR]

The uneven rainfall distribution, limited soil nutrients, and continuous cropping effect in the Loess Plateau restrict the sustainable development of fruit tree/crop (soybean and maize) intercropping systems. A two-year field experiment was conducted to investigate the effects of different water and fertilizer regimes on the soil nutrients and growth of intercropping systems during the crop replacement period. The experiment involved three irrigation levels (0% (I0), 50% (I1), and 80% (I2) of field capacity), two irrigation methods (drip irrigation (DI) and flood irrigation (FI)), and three fertilizer application rates (0 (F0), 375 (F1), and 750 (F2) kg/hm2). The results showed that in 2020 and 2021, the soil water contents increased with increasing irrigation and fertilization. The soil ammonium nitrogen, nitrate nitrogen, and soil organic matter contents in 2021 were 21.0%–68.4% higher than those in 2020. Increasing the fertilizer application rate improved the photosynthesis rate and transpiration rate of apples and maize in 2020 but had a reverse U-shape effect on soybeans in 2021. Irrigation and fertilization increased soybean and maize yields by 2.9%–30.5% compared with the I0F0 treatment. The maize root indicators generally showed an increasing trend followed by a decreasing trend with increasing fertilizer application in 2020, while soybean exhibited an opposite pattern in 2021. The FI1F1 and DI2F2 treatments yielded the optimal economic benefit in 2020 and 2021, respectively. Therefore, from an economic standpoint, FI and DI would have been recommended in 2020 and 2021, respectively. Factor analysis suggested that the DI2F2 treatments had the highest comprehensive benefits over the two years studied. Therefore, we recommend using DI combined with 80% field capacity irrigation and 750 kg/hm2 fertilization to maximize the comprehensive benefits of intercropping systems during the crop replacement period. [ABSTRACT FROM AUTHOR]

Soil microbial taxa have different functional ecological characteristics that influence the direction and intensity of plant–soil feedback responses to changes in the soil environment. However, the responses of soil microbial survival strategies to wet and dry events are poorly understood. In this study, soil physicochemical properties, enzyme activity, and high–throughput sequencing results were comprehensively anal0079zed in the irrigated cropland ecological zone of the northern plains of the Yellow River floodplain of China, where Oryza sativa was grown for a long period of time, converted to Zea mays after a year, and then Glycine max was planted. The results showed that different plant cultivations in a paddy–dryland rotation system affected soil physicochemical properties and enzyme activity, and G. max field cultivation resulted in higher total carbon, total nitrogen, soil total organic carbon, and available nitrogen content while significantly increasing α–glucosidase, β–glucosidase, and alkaline phosphatase activities in the soil. In addition, crop rotation altered the r/K–strategist bacteria, and the soil environment was the main factor affecting the community structure of r/K–strategist bacteria. The co–occurrence network revealed the inter–relationship between r/K–strategist bacteria and fungi, and with the succession of land rotation, the G. max sample plot exhibited more stable network relationships. Random forest analysis further indicated the importance of soil electrical conductivity, total carbon, total nitrogen, soil total organic carbon, available nitrogen, and α–glucosidase in the composition of soil microbial communities under wet–dry events and revealed significant correlations with r/K–strategist bacteria. Based on the functional predictions of microorganisms, wet–dry conversion altered the functions of bacteria and fungi and led to a more significant correlation between soil nutrient cycling taxa and environmental changes. This study contributes to a deeper understanding of microbial functional groups while helping to further our understanding of the potential functions of soil microbial functional groups in soil ecosystems. [ABSTRACT FROM AUTHOR]

Introducing cover crops into maize rotation systems is widely practiced to increase crop productivity and achieve sustainable agricultural development, yet the potential for crop rotational diversity to contribute to environmental benefits in soils remains uncertain. Here, we investigated the effects of different crop rotation patterns on the physicochemical properties, enzyme activities, microbial biomass and microbial communities in soils from field experiments. Crop rotation patterns included (i) pure maize monoculture (CC), (ii) maize–garlic (CG), (iii) maize–rape (CR) and (iv) maize–annual ryegrass for one year (Cir1), two years (Cir2) and three years (Cir3). Our results showed that soil physicochemical properties varied in all rotation patterns, with higher total and available phosphorus concentrations in CG and CR and lower soil organic carbon and total nitrogen concentrations in the maize–ryegrass rotations compared to CC. Specifically, soil fertility was ranked as CG > Cir2 > CR > Cir3 > CC > Cir1. CG decreased enzyme activities but enhanced microbial biomass. Cir2 decreased carbon (C) and nitrogen (N) acquiring enzyme activities and soil microbial C and N concentrations, but increased phosphorus (P) acquiring enzyme activities and microbial biomass P concentrations compared to CC. Soil bacterial and fungal diversity (Shannon index) were lower in CG and Cir2 compared to CC, while the richness (Chao1 index) was lower in CG, CR, Cir1 and Cir2. Most maize rotations notably augmented the relative abundance of soil bacteria, including Chloroflexi, Gemmatimonadetes and Rokubacteria, while not necessarily decreasing the abundance of soil fungi like Basidiomycota, Mortierellomycota and Anthophyta. Redundancy analysis indicated that nitrate-N, ammonium-N and microbial biomass N concentrations had a large impact on soil bacterial communities, whereas nitrate-N and ammonium-N, available P, soil organic C and microbial biomass C concentrations had a greater effect on soil fungal communities. In conclusion, maize rotations with garlic, rape and ryegrass distinctly modify soil properties and microbial compositions. Thus, we advocate for garlic and annual ryegrass as maize cover crops and recommend a two-year rotation for perennial ryegrass in Southwest China. [ABSTRACT FROM AUTHOR]

To evaluate the effects of application of biochar and straw return for consecutive years on N2O emissions and crop yields in North China, a three-year field experiment of applying biochar and straw following a ten-year application was conducted in a wheat–maize rotation system. Four treatments were set up, including F (NPK fertilizer only); FB (NPK fertilizer + 9.0 t·ha−1 biochar); FS (NPK fertilizer + straw); and FSB ((NPK fertilizer + 9.0 t·ha−1 biochar combined with straw). The results showed that compared with the F treatment, the FB treatment significantly reduced soil N2O emissions by 20.2%, while the FS and FSB treatments increased it by 23.7% and 41.4%, respectively. The FB treatment reduced soil N2O emissions by 15.1% in the wheat season and 23.2% in the maize season, respectively. The FS and FSB treatments increased the N2O emissions by 20.7% and 36.7% in the wheat season, respectively, and by 25.5% and 44.2% in the maize season, respectively. In the wheat season, the soil water content (SWC), NO3−-N content and pH were the main influencing factors of the soil N2O emissions. In the maize season, SWC and NO3−-N content were the main influencing factors. In addition, the FB, FS and FSB treatments increased the crop yield by 4.99%, 8.40% and 10.25% compared with the F treatment, respectively. In conclusion, consecutive application of biochar can significantly reduce N2O emissions and improve crop yield. Although FS and FSB treatments can also improve the crop yield, they are not beneficial to suppressing N2O emissions. Therefore, the successive application of biochar is an effective measure to reduce N2O emissions and maintain crop yield. [ABSTRACT FROM AUTHOR]

Crop mapping at an earlier time within the growing season benefits agricultural management. However, crop spectral information is very limited at the early crop phenological stages, leading to difficulties for within-season crop identification. In this study, we proposed a deep learning-based fusion method for crop mapping within the growing season, which first learned a priori information (i.e., pre-season crop types) from historical crop planting data and then integrated the a priori information with the satellite-derived crop types estimated from spectral times-series data. We expect that preseason crop types provided by crop rotation patterns is an effective supplement to spectral information to generate reliable crop maps in the early growing season. We tested the proposed fusion method at three representative sites in the U.S. with different crop rotation intensities and one site with cloudy weather conditions in the Sichuan Province of China. The experimental results showed that the fusion method incorporated the strengths of pre-season crop type estimates and the spectral-based crop type estimates and thus achieved higher crop classification accuracy than the two estimates throughout the growing season. We found that pre-season crop estimates had a higher accuracy in the scenarios with either nearly continuous planting or half-time planting of the same crop. In addition, the historical crop type data strongly affected the performance of pre-season crop estimates, suggesting that high-quality historical crop planting data are particularly important for crop identification at earlier times in the growing season. Our study highlighted the great potential for near real-time crop mapping through the fusion of spectral information and crop rotation patterns. [ABSTRACT FROM AUTHOR]

Soil‐borne diseases are the main cause of yield reduction of Panax notoginseng (Sanqi), and are mainly caused by the enrichment of pathogenic fungi during continuous cropping. In the Wenshan district of Yunnan province, China, where Sanqi is widely cultivated, the rotation of Foeniculum vulgare (fennel) crops with Sanqi crops is assumed to help reduce occurrences of rot in Sanqi roots. However, in a field investigation, we found that this practice actually increased incidences of root rot in Sanqi crops. Using fennel plants obtained from the cropping system, we tested the hypothesis that fennel crops enriched communities of pathogenic fungi of Sanqi. We isolated six endophytic fungi from the roots of fennel plants and identified these based on their morphological characteristics and a sequencing analysis. The isolates were identified as Fusarium oxysporum (FV‐1‐R‐1, FV‐2‐R‐1), Alternaria alternata (FV‐3‐R‐1, FV‐14‐R‐1), Pyricularia grisea (FV‐8‐R‐1) and Colletotrichum truncatum (FV‐11‐R‐4). In a series of inoculation experiments, we verified the pathogenicity of these fungi to Sanqi based on Koch's postulates, and demonstrated that all isolates caused root rot in Sanqi. Our results suggest that fennel is an inappropriate crop choice for rotation with Sanqi because it may serve as an intermediate host for the pathogenic fungi that cause root rot in Sanqi, and thereby exacerbate crop diseases. Our empirical findings provide useful information for enhancing the cultivation of Sanqi and the practice of crop rotation. [ABSTRACT FROM AUTHOR]

Pea (Pisum sativum L.) is a vital leguminous crop farmed worldwide. Pea plays an essential role in China's crop rotation system, but the major restrictions to its cultivation are stability and low yield. Breeding for promising cultivars with a significantly high yield will impact the sustainability of pea production. Additionally, diverse environment trials are crucial in determining the best genotype. The new cultivar "Yunwan 52" was developed by hybridization and subsequently evaluated through yield trials among six pea genotypes across 14 environments during the 2016–2018 growing seasons. The results showed that the average yield of "Yunwan 52" for all tested environments was 2.64 t ha−1 compared to the control cultivar (Yunwan 18, 1.83 t ha−1). Analysis of AMMI variance showed significant differences (p < 0.01) between genotypes, environments, and their interaction. Based on the GGE biplot, some genotypes possessed wide and narrow adaptability to environments, such as Yunwan 52 was considered the most stable and ideal gen-otype across all tested environments. GYT biplot analysis also revealed that this realized cultivar was a superior and stable genotype that can be identified visually by combining all characters in breeding programs. Yunwan 52 distinguishes with purple blossoms and seed coat peas. It is possible to infer that the newly released cultivar "Yunwan 52" has outstanding yield performance and wide adaptability to multiple environmental conditions (resilience to abiotic stress). It will contribute to developing nutritional pea genotypes and increase pea production in irrigated areas. [ABSTRACT FROM AUTHOR]

Timely and accurate extraction of crop planting structure information is of great importance for food security and sustainable agricultural development. However, long time series data with high spatial resolution have a much larger data volume, which seriously limits the quality and efficiency of the application of remote sensing to agriculture in complex crop rotation areas. To address this problem, this paper takes Lujiang County, a typical complex crop rotation region in the middle and lower reaches of the Yangtze River in China as an example, and proposes utilizing the Google Earth Engine (GEE) platform to extract the Normalized Difference Vegetation Index (NDVI), Normalized Difference Yellowness Index (NDYI) and Vertical-Horizontal Polarization (VH) time series sets of the whole planting year, and combining the Simple Non-Iterative Clustering (SNIC) multi-scale segmentation with the Support Vector Machine (SVM) and Random Forest (RF) algorithms to realize the fast and high-quality planting information of the main crop rotation patterns in the complex rotation region. The results show that by combining time series and object-oriented methods, SVM leads to better improvement than RF, with its overall accuracy and Kappa coefficient increasing by 4.44% and 0.0612, respectively, but RF is more suitable for extracting the planting structure in complex crop rotation areas. The RF algorithm combined with time series object-oriented extraction (OB + T + RF) achieved the highest accuracy, with an overall accuracy and Kappa coefficient of 98.93% and 0.9854, respectively. When compared to the pixel-oriented approach combined with the Support Vector Machine algorithm based on multi-temporal data (PB + M + SVM), the proposed method effectively reduces the presence of salt-and-pepper noise in the results, resulting in an improvement of 6.14% in overall accuracy and 0.0846 in Kappa coefficient. The research results can provide a new idea and a reliable reference method for obtaining crop planting structure information efficiently and accurately in complex crop rotation areas. [ABSTRACT FROM AUTHOR]

Small changes in soil aggregates-associated organic carbon and soil nitrogen (N) can induce huge fluctuations in greenhouse gas emissions and soil fertility. However, there is a knowledge gap regarding the responses to long-term continuous rotation systems, especially in N-fixing and non-N-fixing crop wheat in terms of the distribution of soil aggregates and the storage of soil carbon (C) and N in aggregates in the semiarid calcareous soil of Central China. This information is critical for advancing knowledge on C and N sequestration of soil aggregates in rainfed crop rotation systems. Our aim was to determine which legume (soybean (Glycine max)– or mung bean (Vigna radiata)–wheat (Triticum aestivum) rotation practice is more conducive to the formation of good soil structure and C and N fixation. A 10-year field experiment, including a soybean (Glycine max)–winter wheat (Triticum aestivum) rotation (SWR) with yield increments of 2020 compared to 2010 achieving 18.28% (soybean) and 26.73% (wheat), respectively, and a mung bean (Vigna radiata)–winter wheat rotation (MWR) achieving 32.66% (mung bean) and 27.38% (wheat), as well as farmland fallow, was conducted in Henan Province, China. The soil organic carbon (SOC), N content in the soil, and the soil aggregates were investigated. Legume–wheat rotation cropping enhanced the proportion of the >2 mm soil fractions and reduced the <0.053 mm silt + clay in the 0–40 cm soil profile. In the 0–30 cm soil layer, the SWR had a greater increment of the >2 mm aggregate fractions than the MWR. Two legume–winter wheat rotations enhanced the C and N sequestration that varied with soil depths and size fractions of the aggregate. In contrast, the MWR had greater SOC stocks in all fractions of all sizes in the 0–40 cm soil layers. In addition, the greater storage of N in the macro-, micro-, and silt + clay fractions was observed in the 0–30 cm layers; the MWR enhanced the C/N ratios in most of the size aggregates compared with the SWR. The MWR cropping system is more beneficial to the formation of good soil structure and the increasement of C and N reserves in soil. Thus, these findings show that mung bean, in contrast with soybean in the legume–wheat rotation system of a semiarid temperate zone, may offer soil quality improvement. [ABSTRACT FROM AUTHOR]

Vegetable production is an important area of focus in China's agricultural structural adjustment plans, and it serves as one of the essential industries in the rural economy. Several studies have investigated how to optimize vegetable yield and quality through proper irrigation and fertilization to ensure efficient and sustainable development. The main objective of this paper is to examine the impact of different combinations of irrigation and nitrogen inputs on facility-grown vegetables under irrigation and fertilization conditions. Additionally, we aim to identify the optimal irrigation and fertilization regime that can enhance yield quality while also promoting environmental benefits. In this study, we focused on a white radish–tomato facility as the main research object. Using multiple regression and spatial analysis methods, we established three irrigation levels (W1: 100% ET0, W2: 85% ET0, W3: 70% ET0) and four nitrogen application levels (N0: no nitrogen, N1: high nitrogen, locally recommended nitrogen, N2: medium nitrogen, 85% N1, N3: low nitrogen, 70% ET0). We analyzed the effects of an irrigation nitrogen application on vegetable yield, nitrogen bias productivity, soil nitrogen surplus, and integrated N1 warming potential. Our experimental results showed that irrigation volume and nitrogen application had a considerable impact on the yield of facility-grown vegetables, and there was a positive correlation between irrigation water and fertilizer application and yield. By moderately reducing the irrigation volume and increasing nitrogen application, soil nitrogen surplus and nitrogen fertilizer bias productivity can be effectively improved. In addition, our study found that the integrated warming potential and the bias productivity of nitrogen fertilizer showed a quadratic relationship, which indicated that the integrated warming potential and nitrogen fertilizer bias productivity would first become larger and then decrease under the condition of increasing the irrigation volume and nitrogen application rate. By analyzing the difference between W2N2 and W1N1, we found that moderate water-saving and nitrogen reduction did not affect yield. Furthermore, it effectively improved the bias productivity of nitrogen fertilizer. Therefore, it is recommended that when the irrigation volume is between 560 and 650 mm and the nitrogen application rate is between 325 and 400 kg/hm2 and more than 90% of the maximum value of yield, nitrogen fertilizer bias productivity can be achieved at the same time while also having a lower integrated warming potential. This range of irrigation and nitrogen application intervals is close to optimal. Our study provides a guiding basis for rotational soil nitrogen balance, optimal water, and nitrogen management of facility-grown vegetables. We propose an optimal water and nitrogen management strategy that is more efficient and sustainable under the plant culture model. This strategy provides a new way of thinking and methodology for high-quality production that is water-saving and fertilizer-saving while addressing the water and soil resource problems that exist in the current development of the vegetable industry. [ABSTRACT FROM AUTHOR]

Growing potatoes (Solanum tuberosum) using the idle rice fields in Southern China and the Indo-Gangetic Plains of India in the winter season through the rice–potato rotation (RC) system could support future food security. However, the modulation capacity of the RC system on soilborne fungal pathogens is still unclear. In the current study, a pot experiment was designed and conducted to monitor the dynamics of soil fungal community composition between the potato monoculture (CC) system and the RC system, where the two systems were set with the same soil conditions: autoclaving with fertilization; autoclaving without fertilization; autoclave-free with fertilization; and autoclave-free without fertilization. Then, the uncultivated soil (CK) and root-zone soil samples of conditions under the two systems were collected, and then soil physiochemical properties and enzymatic activities were determined. Next, the high-variable region (V5–V7) of fungal 18S rRNA genes of the samples were amplified and sequenced through the PCR technique and the Illumina Miseq platform, respectively. Finally, the fungal species diversity and composition, as well as the relative abundance of fungal pathogens annotated against the Fungiuld database in soil samples, were also investigated. The results showed that the RC could significantly (p < 0.05) increase soil fungal species diversity and decrease the relative abundance of soil fungal pathogens, where the RC could suppress 23 soil fungal pathogens through cultivating the rice during the summer season and 93.75% of the remaining pathogens through winter-season cultivation. Seven-eighths of the conditions under RC have lower pathogenic MGIDI indices (6.38 to 7.82) than those of the CC (7.62 to 9.63). Notably, both rice cultivation and winter planting reduced the abundance of the pathogenic strain ASV24 under the Colletotrichum genus. The bipartite fungal network between the pathogens and the non-pathogens showed that the pathogenic members could be restricted through co-occurring with the non-pathogenic species and planting crops in the winter season. Finally, the redundancy analysis (RDA) indicated that soil pH, electronic conductivity, available phosphorus content, and various enzyme activities (cellulase, urease, sucrase, acid phosphatase, catalase, polyphenol oxidase) could be the indicators of soil fungal pathogens. This experiment demonstrated that the rice–potato rotation system outperformed the potato monoculture on suppressing soilborne fungal pathogenic community. [ABSTRACT FROM AUTHOR]

The employment of biochar in crop production can not only improve soil quality, but also helps the field ecosystem to fix carbon and reduce emissions. Although the benefits of their application in crop production have been more and more confirmed, it is not clear when it comes to the acidic soil of tobacco and rice rotation. A tobacco–rice rotation experiment was conducted in southern China to probe the application value of biochar under these conditions. Three biochar application rates were employed in this experiment. BC0 (without biochar), BC25 (25 t ha−1), and BC50 (50 t ha−1). The findings show that biochar significantly boosted soil fertility and crop yields. Meanwhile, the soil organic carbon of tobacco rice rotation field with biochar increased by 31.76%. After a whole growth period of tobacco and rice, the cumulative emission reduction of CO2 and N2O from the soil by biochar were 15,944 kg ha−1 and 1810 g ha−1, respectively. The use of biochar not only significantly improved the bacterial diversity of tobacco and rice rotation soil, but also altered the original microbial community structure. The profusion of Proteobacteria and Acidobacteria was reduced and the abundance of Actinobacteria and Bacteroidetes was enhanced in the treatments with biochar. Among them, Sphingomonadales, Planctomycotes, and Ktedonobacteria, which are beneficial to plant growth and soil health, have become key phylotypes. The carbon balance analysis data show that the net carbon sequestration of the two treatments with biochar is positive, while that of the treatment without biochar is negative. In terms of economic benefit, the application of biochar increased the average of 2.055 CNY kg−1 consumed energy (CE) in the whole tobacco–rice rotation system. The ecological benefit was 0.51 kg C kg−1 CE. In conclusion, biochar can be effectively used in the practice of tobacco–rice rotation and acidic soil improvement in southern China. To explore the application value of biochar on acidic soil in south China, the effects of different application rates of biochar on crop production, carbon sequestration, and emission reduction were compared through a tobacco and rice rotation experiment. The results show that field application of biochar is not only economically feasible in agricultural production, but also has positive ecological benefits. [ABSTRACT FROM AUTHOR]

Conventional and scientific cropping patterns are important in realizing the sustainable utilization of Black soil and promoting the high-quality development of agriculture. It also has far-reaching significance for protecting Black soil and constructing the crop rotation system to identify the cropping patterns in Northeast China and analyze their spatio-temporal dynamic change. Using the geo-information Tupu methods and transfer land matrix, this study identified the cropping patterns and their spatio-temporal change based on remote sensing data for three periods, namely 2002–2005, 2010–2013, and 2018–2021. The main results revealed that the maize continuous, mixed cropping, maize-soybean rotation, and soybean continuous cropping patterns were the main cropping patterns in Wangkui County, with the total area of the four patterns accounting for 95.28%, 94.66%, and 81.69%, respectively, in the three periods. Against the backdrop of global climate warming, the cropping patterns of continuous maize and soybean and the mixed cropping pattern in Wangkui County exhibited a trend towards evolving into a maize-soybean rotation in the northern region. Moreover, the maize-soybean rotation further evolved into a mixed cropping system of maize and soybean in the north. Furthermore, the spatio-temporal evolution of cropping patterns was significantly driven by natural and social factors. Specifically, natural factors influenced the spatio-temporal patterns of variation in cropping patterns, while social factors contributed to the transformation of farmers' cropping decision-making behavior. Accordingly, new insights, institutional policies, and solid solutions, such as exploring and understanding farmers' behavior regarding crop rotation practices and mitigating the natural and climatic factors for improving food security, are urgent in the black soil region of China. [ABSTRACT FROM AUTHOR]

The root-knot nematode (RKN) disease is a highly destructive soilborne disease that significantly affects peanut yield in Northern China. The composition of the soil microbiome plays a crucial role in plant disease resistance, particularly for soilborne diseases like RKN. However, the relationship between the occurrence of RKN disease and the structure and diversity of bacterial communities in peanut fields remains unclear. To investigate bacterial diversity and the community structure of peanut fields with severe RKN disease, we applied 16S full-length amplicon sequencing based on the third high-throughput sequencing technology. The results indicated no significant differences in soil bacterial α-diversity between resistant and susceptible plants at the same site. However, the Simpson index of resistant plants was higher at the site of peanut-wheat-maize rotation (Ro) than that at the site of peanut continuous cropping (Mo), showing an increase of 21.92%. The dominant phyla identified in the peanut bulk soil included Proteobacteria, Acidobacteria, Actinobacteria, Planctomycetes, Chloroflexi, Firmicutes, and Bacteroidetes. Further analysis using LEfSe (Linear discriminant analysis effect size) revealed that Sulfuricellaceae at the family level was a biomarker in the bulk soil of susceptible peanut compared to resistant peanut. Additionally, Singulisphaera at the genus level was significantly more enriched in the bulk soil of resistant peanut than that of susceptible peanut. Soil properties were found to contribute to the abundance of bacterial operational taxonomic units (OTUs). Available phosphorus (AP), available nitrogen (AN), organic matter (OM), and pH made a positive contribution to the bacterial OTUs, while available potassium (AK) made a negative contribution. The metabolic pathway of novobiocin biosynthesis was only enriched in soil samples from resistant peanut plants. Eleven candidate beneficial bacteria and ten candidate harmful strains were identified in resistant and susceptible peanut, respectively. The identification of these beneficial bacteria provides a resource for potential biocontrol agents that can help improve peanut resistance to RKN disease. Overall, the study demonstrated that severe RKN disease could reduce the abundance and diversity of bacterial communities in peanut bulk soil. The identification of beneficial bacteria associated with resistant peanut offered the possibility for developing biocontrol strategies to enhance peanut resistance to RKN disease. [ABSTRACT FROM AUTHOR]

The introduction of leguminous crops for crop rotation can mitigate the negative effects of continuous cropping on soil health. In this experiment, we designed ten cropping patterns to optimise the rotation effect with different combinations of crop types, planting years, and order in a mainly potato-growing region. A 5-year cycle with three crops, undertaken in Inner Mongolia since 2009, was used to test soil properties and microbial structure. The relative abundance of plant growth-promoting bacteria (PGPB) was 32.1% in the cycle oats oats alfalfa alfalfa alfalfa and 22.4% in 5-year mono-cropping of alfalfa, which was higher than that of mono-cropping of potatoes and other crop rotations. Soil moisture was the main factor influencing bacterial and fungal communities. The effect of the type of plant introduced into the rotation on soil was greater than that of the number of years a certain crop was planted in the rotation, and this effect was greater than that of planting order. The findings suggest that the rotation of oats and alfalfa mixed → alfalfa → oats → potatoes → potatoes is a suitable 5-year cycle to maintain biodiversity and better soil physico-chemical properties for sustainable agriculture. [ABSTRACT FROM AUTHOR]

In order to further understand types of peanut diseases in field, the regularity of main diseases and influencing factors in northern Henan province, accurately prevent and control the field diseases during peanut growth period, in this study, peanut diseases in field were investigated in the field plots including the spring sowing continuous cropping(winter fallow) and peanut wheat rotation fields in Nanzhaoshi village, Datun township, Puyangcity from 2019 to 2021. The occurrence regularity of the main diseases was analyzed, and the influencing factors were studied. The investigation found that the diseases at the early stage of peanut growth were mainly stem rot, early leaf spot and scorch spot and so on, the diseases in at the late stage of growth were mainly early leaf spot, late leaf spot, web blotch, southern blight, and so on. Among them, leaf spot disease was a serious disease that occurred every year during the growth of peanut in the tested field. The correlation analysis results showed that the correlations between the disease index of leaf spot and the average relative humidity of ten days as well as average value of average temperature of ten days were 0.373, -0.311, respectively, reached the extremely significant and significant levels, respectively, indicating that the temperature and the relative humidity had significant and extremely significant impacts on the occurrence of leaf spot. From the results of general linear models univariate analysis, the effects of tillage methods, years, and their interaction on the occurrence of leaf spot disease were not significant, the continuous cropping effect and accumulation of pathogenic bacteria in different years were not obvious. With the advance of growth period, the incidence of leaf spot disease increased, which may be related to the peanut leaf spot disease mainly caused by late leaf spot disease in northern China, as well as the accumulation and repeated infection of leaf spot pathogens in the fields in the year. This study clarified the types, occurrence regularity, and influencing factors of peanut field diseases in northern Henan, and provided a theoretical basis for targeted disease prevention and control. [ABSTRACT FROM AUTHOR]

Globally, agricultural soils are considered as one of the most important sources of greenhouse gas (GHG) emissions. No-tillage (NT), one of the most admired ways of climate-smart agriculture, has been deemed to have co-benefit to mitigation of GHG emissions and sustainability for crop yield, however, the effect of NT on GHG emissions is controversial. This study analyzed the overall effects of NT on GHG emissions, as well as the moderators that significantly influenced the overall effects, of the wheat-based rotation cropping systems in China through meta-analysis. The results showed that the overall effect size of NT on methane (CH4) uptake, nitrous oxide (N2O) emission, and global warming potential (GWP) was 0.70 (95% Confidence Interval (CI): 0.21–1.19), −0.27 (95%CI: −0.72–0.18), and −0.39 (95%CI: −1.01–0.23), respectively. In temperate climate zones with alkaline soils, the nitrogen application rate of 120–240 kg/ha, NT could significantly reduce GHG emissions and GWP. However, the mitigation effect will be weakened along with NT duration, except for proper straw addition. Overall, NT has the potential to reduce GHG emissions from wheat-based rotation systems in China, but it is necessary to implement NT depending on local conditions, soil characteristics, and field management. [ABSTRACT FROM AUTHOR]

Background: Potato (Solanum tuberosum L.) continuous cropping causes the decrease of tuber yield, deterioration of quality and soil degradation in the semi-arid area. These negative effects can generally be mitigated by legume rotation and mulching. However, little is known about how can mulching and legume rotation alleviate the above damage through altering soil environment. Methods: A field experiment was conducted to investigate changes in soil properties and microbial community in response to legume rotation and mulching under six planting patterns: potato continuous cropping without film mulching (PC), potato continuous cropping with film mulching (PCF), potato–broad bean rotation without film mulching (R1), potato–broad bean rotation with film mulching (R1F), potato–pea rotation without film mulching (R2) and potato–pea rotation with film mulching (R2F). Results: Compared with the PC, the R1F and R2F had significantly enhanced the contents of alkaline nitrogen (AN), available phosphorus (AP), available potassium (AK), total carbon (TC) and total nitrogen (TN), but reduced soil pH and electrical conductivity (EC). The Shannon index of fungi in R1F and R2 was significantly higher than other treatments. The dominant bacterial and fungal phyla of each treatment was Proteobacteria and Ascomycota. R1, R1F, R2 and R2F enhanced the relative abundance of metabolic fungi and altered key differential microbial species. Soil EC, AN and AK were major factors influencing the soil bacterial and fungal communities. Conclusion: Overall, the study demonstrated that potato-broad bean/pea rotation with mulching can be adopted as the preferred cropping systems to alleviate potato continuous cropping obstacles through enhancing soil fertility and regulating soil microbial communities in the semi-arid of Loess Plateau, China. [ABSTRACT FROM AUTHOR]

Freshwater resources are becoming increasingly scarce in coastal areas, limiting crop productivity in coastal farmlands. Although the characteristic of crop water use is an important factor for water conservation in coastal farmlands, it has not been studied extensively. This study aimed to depict the water use process of soil–plant systems under saline stress in coastal ecosystems and optimize water management. An intensive observation experiment was performed within China's Yellow River Delta to identify the water use processes and crop coefficients (KC) and also quantify the impacts of salt stress on crop water use. The results show that shallow groundwater did not contribute to soil water in the whole rotation; KC values for wheat–maize, wheat–sorghum, and wheat–soybean rotation systems were 45.0, 58.4, and 57% less, respectively, than the FAO values. The water use efficiency of the maize (8.70) and sorghum (9.00) in coastal farmlands was higher than that of the soybean (4.37). By identifying the critical periods of water and salt stress, this paper provides suggestions for water-saving and salinity control in coastal farmlands. Our findings can inform the sustainable development of coastal farmlands and provide new insights to cope with aspects of the global food crisis. [ABSTRACT FROM AUTHOR]

Direct-seeded rice (DSR) has received much attention because of its advantages in having low labor costs compared to the traditional transplanted rice (TPR). Investigating the differences in evapotranspiration (ET) partitioning and crop coefficients (Kc) between DSR and TPR is essential in understanding how agricultural water demand is affected by crop rotation. In this study, the water fluxes of two-year (2017–2018) growing seasons were collected from a pair of eddy covariance (EC) towers for DSR and TPR in the Poyang Lake Basin, Southern China. This study aims to compare the seasonal characteristics of the ET components (evaporation, E, and transpiration, T) and dual crop coefficients (basal crop coefficient, Ks·Kcb, and soil/water crop coefficient, Ke) of DSR with those of TPR. The ET values for the 2017 and 2018 growing seasons were 374 mm and 436 mm for the DSR, respectively, and 309 mm and 342 mm for the TPR. The seasonal T/ET values in 2017 and 2018 were 0.40 and 0.46 for the DSR, respectively, and 0.49 and 0.52 for the TPR, indicating that the higher ET values for the DSR can be mostly attributed to E. The DSR had overall higher Kc values than the TPR because of free water evaporation during the initial stage and a higher plant density. Our results enrich the Kc dataset for DSR and have great implications for the sustainable irrigation of the Poyang Lake Basin in the future. [ABSTRACT FROM AUTHOR]

Agricultural production emission is responsible for 23% of all anthropogenic greenhouse gas emissions in China in recent years. Particularly, a large number of parts are accounted for the carbon dioxide equivalent of China’s greenhouse gas emissions in global emissions. Among them, arable land also serves as a significant carbon sink. It is also crucial to explore novel techniques for soil organic carbon sequestration in cultivated land. Numerous agricultural strategies have been proposed to promote carbon sequestration and carbon sinks in cultivated land in modern agriculture. At the same time, future research can be required to determine the primary driving factors, and then to systematically evaluate the soil carbon sequestration. However, it is still lacking on systematic research on the characteristics and driving factors of soil organic carbon stock in cultivated land. Taking the middle-lower reaches of the Yangtze River Region (the typically agricultural regions of China) as the study areas, this study aims to achieve carbon sequestration and sinks in great agriculture. The observation data of organic carbon stock was collected from 59 positioning experimental stations. The soil organic carbon density change rate was also quantified in the different cultivated land. A random forest (RF) model was then used to explore the driving factors on the soil organic carbon density change rate. The results show that: 1) The variation ranges of soil organic carbon density change rate were −1 548.15-3 577.10 kg/(hm² ·a) and −261.89-3 245.01 kg/(hm² ·a), respectively, in the paddy fields and dry lands. But there was no significant difference between the paddy fields and dry lands. Besides, different crop rotation patterns posed different potentials for organic carbon sequestration. Specifically, the rice-wheat and oilseed rape-cotton rotation patterns performed better than the rest. 2) There was a great effect of the organic fertilizer nitrogen content, soil pH value, chemical fertilizer nitrogen, and straw nitrogen content on the soil organic carbon density change rate in the paddy field. The mean decrease accuracy (MDA) values were 0.49, 0.32, 0.23, and 0.15, respectively. By contrast, some effect was found in the mean annual precipitation, soil organic carbon content, mean annual temperature, multiple cropping index, paddy, and dry crop rotation. Furthermore, the organic and chemical fertilizer nitrogen content shared a great effect on the soil organic carbon density change rate in the dryland. The MDA values were 0.98, and 0.10, respectively. There were no major factors in the soil pH value, mean annual temperature, clay fraction, multiple cropping index, and straw nitrogen content. 3) Partial dependence analysis showed that the increasing soil organic carbon stock in the paddy fields tended to occur when combining the application of organic and chemical fertilizer, or the soil pH value to the neutral, and the straw returning to the field. The application of organic and chemical fertilizer tended to increase the organic carbon stock in the drylands. The soil organic carbon stock increased in cultivated land when the proportion of organic fertilizer nitrogen accounted for 10% to 30% of the total nitrogen fertilizer. Therefore, it was recommended that the soil pH value should be reasonably regulated to combine the application of organic and chemical fertilizers for conservation and carbon sequestration in the paddy fields. Therefore, the neutral pH value can be expected to achieve cultivated land carbon sequestration and high crop yield in tandem. This finding can provide a strong reference for the soil organic carbon sequestration and sink enhancement in cultivated land in the middlelower reaches of the Yangtze River Region. [ABSTRACT FROM AUTHOR]

Arid and semiarid areas generally face problems of natural resource degradation. In this paper, two indicators are proposed to characterize the utilization of rainwater: rainwater resource utilization quantity (RRU, mm) and rainwater resource utilization rate (RRUR, dimensionless ratio). A spatiotemporal assessment model (rainwater utilization assessment [RUA] model) for the RRUR and its influencing factors is constructed. The RUA model is based on Soil and Water Assessment Tool and Geographically Temporal Weighted Regression. The Zuli River Basin, located on the Loess Plateau in China, was selected as the study basin. The results show that the annual averages of the RRU and RRUR are 164 mm and 0.44, respectively, in the study basin. The RRU ranged from 71.4 to 243.2 mm, and the RRUR ranged from 0.32 to 0.53 during the evaluation period. Eight explanatory variables were selected, of which the leaf area index (LAI) and rainfall had a significant positive effect on RRUR, but there was spatial and temporal variability in the effects. The forest rehabilitation and crop rotations that can increase the LAI can effectively increase the RRUR, which increased by 0.10 and 0.11, respectively, and the increase in RRU was at least 36.42 mm, with a water volume of 3.85 × 108 m3. The impact of grassland rehabilitation and parallel terracing on the RRUR was small. We found that there is an interval effect and a threshold effect on rainfall utilization in the basin. The interval effect causes the RRUR to fluctuate within a certain range for rainfall intervals of 300–400 or 400–500 mm (Zuli River Basin). Threshold effects can guide the determination of the potential for rainwater utilization in different areas to ensure that the RRUR can be effectively enhanced with management measures. Recommendations for Resource ManagersWe have constructed an assessment model of rainwater resource utilization (RRU) and influencing factors.We have proposed two evaluation indices based on water balance, namely, the RRU quantity and rainwater resource utilization rate (RRUR).The leaf area index of vegetation is the most important influence on rainwater utilization, and the more severe the drought is, the more effective the regulation of water cycle processes by vegetation.The interval effect causes uncertainty in the RRUR for a certain interval of rainfall, with the RRUR fluctuating within a defined range.The threshold effect can guide us in determining the potential for rainwater utilization, and areas where the current RRUR is below the threshold can take management measures to ensure that the RRUR can be effectively increased. [ABSTRACT FROM AUTHOR]

Soil salinization significantly restricts crop yield, animal foraging, and biomass production for biofuels. Identifying an efficient farming system to mitigate these concerns has become a major research focus. The present study addresses the potential of rotating triticale and sweet sorghum at various planting densities to alleviate soil salt stress, enhance production, improve agronomic characteristics, and boost soil microbial communities in a saline agricultural environment in East China. Several indicators in 2017 and 2018. Results show that triticale and sweet sorghum planting significantly decreased soil salt contents compared to bare land plots. Multiple agronomic traits were measured for each planting density. For triticale, a density of 180 × 104 plants ha−1 showed the best plant height, tiller number per plant, yield, and lodging rate; for sweet sorghum, a density of 7 × 104 plants/ha showed the best plant height, yield, and lodging rate. High-density planting of triticale (180, 260, 320 × 104 plants/ha) and sweet sorghum (7, 8, 9 × 104 plants/ha) was associated with high counts of bacteria, Actinomycetes, and salt-tolerant Actinomycetes. However, planting density had no significant effect on the counts of fungi or salt-tolerant bacteria. Redundancy Discriminant Analysis (RDA) showed that plant height, yield, lodging rate, bacteria, salt-tolerant bacteria, Actinomycetes, and salt-tolerant Actinomycetes were negatively correlated with soil salinity, while tiller number per plant and stem thickness were positively correlated with soil salinity. In conclusion, a rotation system of triticale and sweet sorghum with planting densities of 180 × 104 and 7 × 104 plants/ha, respectively was established to improve and make full use of saline soil. [ABSTRACT FROM AUTHOR]

Appropriate crop rotations are beneficial for food security and carbon sequestration. In cool and semiarid rain‐fed areas, however, the effect on carbon sequestration in soil and the soil–crop system is not clear. In this study, a crop rotation field experiment was carried out on the Loess Plateau, China, involving (1) wheat continuous cropping (WCC), (2) maize continuous cropping (MCC), (3) potato continuous cropping (PCC) and (4) wheat–maize–potato rotating cropping (RC). All treatments were tilled once, and then, plastic mulched immediately to inhibit evaporation. We found that the rotating cropping system improved water storage in the 0–300 cm soil profile by 65.8 mm through the 6 years, while MCC depleted deep soil moisture. In a drought year, total dry matter (DM) for the rotating cropping was greater by 23.9% and 79.3% and harvested carbon quantity (HCQ) by 0.6 and 1.8 Mg ha−1 compared with WCC and MCC systems, respectively. Total evapotranspiration significantly decreased by 14.5% compared with MCC, with no significant change compared with WCC and PCC. The soil organic carbon (SOC) concentration at 20–30 cm depth in the rotating cropping system was 36.0%, 28.0% and 30.3% greater than those of WCC, MCC and PCC, respectively. Similarly, the SOC sequestration rate at this depth was higher by 3.8, 3.2 and 3.4 Mg ha−1, respectively. The pure carbon accumulation (PCA) of the rotating cropping system significantly increased compared with WCC and PCC, resulting in increased water use efficiency of pure carbon accumulation (WCP) by 11.1, 2.2 and 3.1 Mg ha−1 mm−1 compared with the WCC, MCC and PCC systems, respectively. Overall, the rotating cropping (RC) system maintained better soil water conditions, sustained crop development and SOC sequestration, especially optimizing the relationship between crop water utilization and SOC sequestration in soil–crop system in the cool semiarid rain‐fed area. [ABSTRACT FROM AUTHOR]

This study examined the adaptation level of climate-smart agricultural (CSA) practices among the farmers and the factors influencing the adoption of CSA practices in the Fujian Province, China. In this study, questionnaire survey data was analyzed, and 600 respondents were randomly selected as sample through randomly sampling technique. Descriptive statistics, adoption level index (ALI), and binary logit model were used for data analyses. These results indicated a moderate adoption level of CSA practices in the Fujian Province. Use of improved varieties, conservation tillage, fallow cropping, new technology, and intercropping were prevalent CSA practices among the farmers in the study area. In addition, farmers were not very interested in using herbicides on their farmlands, and only 20% of the respondents used herbicides in the Fujian Province. Except for Nindge village in the Fujian Province, all other studied villages have adapted to using organic fertilizer (around 50% of total respondents). However, more than 60% of respondents have claimed they still use chemical weed/insect/disease control in their farmlands. Age and working experience of farmers were the most influencing factors affecting the increase in the adoption of CSA practices among the farmers, and to the results of the binary logit model, education was not significant. Landholding, loan access, and access to agricultural extensions and organizations considerably impacted the adoption level of CSA practices among the farmers in the Fujian Province. Finally, this study will be helpful to decision-makers to make appropriate decisions to minimize the impact of climate change on agriculture and improve the standard of human life and food security. [ABSTRACT FROM AUTHOR]

Straw returning to the field can reduce the use of chemical fertilizers and improve the utilization rate of chemical fertilizers on the basis of improving soil fertility. Straw resources can also be effectively utilized during this time. However, there is a different replacement rate of chemical fertilizer with straw return in China, due to the varying crop planting systems with the various soil fertility. In this study, a critical review was proposed to comprehensively analyze the replacement potential of chemical fertilizer by straw returning in field experiments. The data were collected from the published literature data of “CNKI” from 2000 to 2021 and 32 field experiments of straw returning to fields in Hubei Province from 2013 to 2021. The search keywords were set as “straw return”, “nitrogen (N) fertilizer”, “phosphorus (P) fertilizer”, “potassium (K) fertilizer”, and “fertilizer replacement and reduction”. The criteria for selecting data from the literature are as follows: 1) The study was conducted in China; 2) The experimental crop was rice, wheat, maize or oilseed rape; 3) The same experiment needed to include the paired treatment and control group. The treatment group was the chemical fertilization reduction with straw return, whereas, the control group was chemical fertilization without straw return. The rest experimental conditions of the treatment and control group were strictly consistent; 4) The level ranges of chemical fertilizer were 150-250 kg/hm² (N), 40-120 kg/hm² (P2O5), and 50-150 kg/hm² (K2O); 5) There were the clear starting and ending years of the experimental period; 6) The published data included the fertilizer amount, crop yield, basic physical and chemical properties of soil. Eventually, 487 published datasets were collected during the years 2000-2021, while, 641 experimental datasets from 32 field experiments that conducted in Hubei Province from 2013 to 2021. After that, the datasets were utilized to determine the proportion of N, P, and K fertilizer reduction by straw return for the major crops, in order to estimate the chemical fertilizer saving potential of straw return on a national scale. Specifically, the average replacement ratios of N, P, and K fertilizers by straw return were 12.2%, 23.9% and 43.5%, respectively. There was no significant difference in the replacement ratios by straw return among the crops. In rotation systems, the average replacement ratio of N and P fertilizer by straw return in the paddy-upland rotation system (e.g., rice monoculture and rice-oilseed rape rotation) were 5.0-12.9 and 18.0-24.8 percentage points higher than those in the upland rotation system (e.g., wheat-corn rotation and corn monoculture). In addition, the supply capacity of soil nutrients was an important influencing factor on the replacement reduction potential of chemical fertilizer (especially P and K fertilizer) by straw return. The reduction ratios of P and K fertilizer by straw return were 9.1-11.5 and 6.2-14.2 percentage points lower in soil with a high nutrient supply capacity than those with the low one, respectively. According to the planting area and fertilizer consumption of various crops in 2020, the national N, P2O5, and K2O fertilizer for the rice, wheat, maize, and oilseed rape seasons could have reduced by 239.48×104, 227.73×104 and 451.98×104 t, respectively, accounting for 12.6%, 25.0%, and 48.5% of the current N, P2O5 and K2O fertilizer consumptions. The total cost of chemical fertilizer was saved 478.98×108 Yuan per year by straw return. A large number of field experiments were implemented for the comprehensive analysis of the reduction potential of chemical fertilizer by straw return. The finding can provide the theoretical basis and data support for the high-use efficiency of chemical fertilizers for the major crops in China. [ABSTRACT FROM AUTHOR]

Paddy rice cropping patterns (PRCPs) play important roles in both agroecosystem modeling and food security. Although paddy rice maps have been generated over several regions using satellite observations, few studies have focused on mapping diverse smallholder PRCPs, which include crop rotation and are dominant cropping structures in South China. Here, an approach called the feature selection and hierarchical classification (FSHC) method was proposed to effectively identify paddy rice and its rotation types. Considering the cloudy and rainy weather in South China, a harmonized Landsat and Sentinel-2 (HLS) surface reflectance product was employed to increase high-quality observations. The FSHC method consists of three processes: cropping intensity mapping, feature selection, and decision tree (DT) model development. The FSHC performance was carefully evaluated using crop field samples obtained in 2018 and 2019. Results suggested that the derived cropping intensity map based on the Savitzky–Golay (S-G) filtered normalized difference vegetation index (NDVI) time series was reliable, with an overall accuracy greater than 93%. Additionally, the optimal spectral (i.e., normalized difference water index (NDWI) and land surface water index (LSWI)) and temporal (start-of-season (SOS) date) features for distinguishing different PRCPs were successfully identified, and these features are highly related to the critical growth stage of paddy rice. The developed DT model with three hierarchical levels based on optimal features performed satisfactorily, and the identification accuracy of each PRCP can be achieved approximately 85%. Furthermore, the FSHC method exhibited similar performances when mapping PRCPs in adjacent years. These results demonstrate that the proposed FSHC approach with HLS data can accurately extract diverse PRCPs over fragmented croplands; thus, this approach represents a promising opportunity for generating refined crop type maps. [ABSTRACT FROM AUTHOR]

Rotational straw return technique is considered an effective measure for improving soil quality and maintaining soil microorganisms. However, there are few reports on the influence of wheat-maize crop rotation and straw-returning tillage on crop soil microbial communities in China. This study aimed to investigate how wheat or maize straw-incorporation practices affect bacterial and fungal communities under wheat-maize rotational farming practices. To clarify the effects of strawincorporation on microbial composition, microbial communities from soils subjected to different treatments were identified using high-throughput sequencing. Our results showed that, before corn planting, wheat and maize straw returning reduced bacterial density and increased their diversity but had no effect on fungal diversity. However, before wheat planting, returning wheat and corn stalks to the field increased the diversity of soil bacteria and fungi, whereas returning corn stalks to the field reduced the diversity of fungi and other microorganisms. Straw return significantly increased the relative abundance of Ascomycota in the first season and decreased it in the second season; however, in the second season, wheat straw return increased the relative abundance of Bradyrhizobium, which can promote the soilmicrobial nitrogen cycle and provide nitrogen to the soil. Wheat and maize straw return increased the relative abundance of Chaetomium, whereas, individually, they decreased the relative abundance. In addition, we detected two fungal pathogens (Fusarium and Trichoderma) under the two planting patterns and found that the relative abundance of pathogenic Fusarium increased with wheat straw return (FW and SW). Trichoderma increased after treatment with maize straw return before wheat planting (S group). These results suggest that wheat straw return (FW and SW) and maize straw return might have a negative impact on the pathogenic risk. Therefore, further studies are needed to determine how to manage straw returns in agricultural production. [ABSTRACT FROM AUTHOR]

Wheat/soybean rotation is an important double-cropping system in the Huang-Huai-Hai plain of China. Continuous soybean cropping could cause soil quality deterioration and plant growth inhibition. However, the effects of continuous wheat/soybean cropping on soybean rhizosphere microbes remain largely unknown. In this study, we compared the soybean yield and rhizosphere soil microbial community between continuous winter wheat/summer soybean (W/S) with two harvests in one year and winter wheat/summer soybean-winter wheat/summer maize (W/S-W/M) with four harvests in two years. The results showed that the soybean yield in the W/S group significantly (p < 0.05) declined within the first two years. The W/S-W/M showed higher soybean yield and soil fertility index than the W/S group. The sequencing results revealed that cropping rotation had a higher impact on the fungal community than the bacterial community. The W/S group showed 22.08–23.01% higher alpha diversity of the fungal community, but the alpha diversity of the bacterial group did not vary significantly in this group. The fungal community composition in the W/S and W/S-W/M groups differed significantly. In the W/S-W/M group, a higher relative abundance of plant growth-promoting fungi (e.g., Mortierella), nematophagous fungi (e.g., Plectosphaerella), and biological control fungi (e.g., Coniothyrium) was observed. In the W/S group, a higher relative abundance of lignocellulose-degrading fungi (e.g., Trechispora, Myceliophthora, Botryotrichum, and Coniochaeta) and pathogenic fungi (e.g., Pyrenochaetopsis and Cyphellophora) was observed. LEfSe analysis demonstrated that Mortierella, Myceliophthora, and Trechispora could serve as crucial biomarkers. Mortierella was positively associated with available P levels and negatively associated with NO3−-N levels and pH while Trechispora showed the opposite trend. The findings of this study could enhance the current understanding of the mechanisms associated with the continuous wheat/soybean cropping obstacles and ensure the sustainability of agricultural production. [ABSTRACT FROM AUTHOR]

Soil microbes play an integral role in agricultural production and soil fertility, while limited information is available about the effects of long‐term fertilization on rice (Oryza sativa L.)–rapeseed (Brassica napus L.) rotation yield, soil properties, and microbial communities in central China. Here, we report the response of plant–soil system to different mineral fertilizer inputs, including the balanced fertilization with N, P, and K (NPK) fertilizers and unbalanced fertilizers without one of the major nutrients (PK, NK, and NP) for 10 years. Compared with the NPK treatment, the average annual decrease rates of rice and rapeseed yield in the PK, NK, and NP treatments were 12.5%, 18.1%, 6.4% and 33.1%, 54.8%, 16.0%, respectively. Long‐term fertilization significantly changed the soil chemical properties, especially the pH and available K content. Compared with the NPK fertilization, the NK treatment increased the soil microbial composition and diversity, whereas PK and NP treatments had a reverse impact. Available K, pH, and slowly available K were closely related to alterations of the dominant bacterial community. On the contrary, the Olsen‐P, slowly available K, and pH were significantly correlated with the fungal community. Soil properties changed by fertilization had a more direct effect on crop yield than the microbial community; moreover, the bacterial group had a higher influence than the fungal group on crop yield. Therefore, a balanced nutrient input using NPK fertilization is an effective management strategy for soil biological fertility and sustainable crop yield. Core Ideas: Crop yields were sensitive to P deficiency than N and K deficiencies.Coupling interaction existed between soil properties and microbes on yield.The responses of microbial diversity to P, K, and N deficiency were different.Available K, pH, and slowly available K were closely related to bacterial community.Olsen‐P, slowly available K, and pH were significantly correlated with fungal community. [ABSTRACT FROM AUTHOR]

Returning straw directly to the field soil is an important strategy that is widely advocated for the disposal of cereal straw. Straw carbonization to form biochar is an innovative approach for treating straw, and its incorporation into the soil is beneficial for improving soil quality. To assess the long-term impacts of these two technologies on greenhouse gas (GHG) emissions and crop yields, a decade-long field study, comparing three treatments, namely direct incorporation of straw from the crop into the field (SCF), incorporation of biochar from straw into the field (BCF), both combined with chemical fertilizer, and the incorporation of chemical fertilizer alone into the field (CF), was conducted on a rice-wheat rotation system in eastern China. Results showed that SCF and BCF achieved the same rice yield as CF treatment alone, while BCF caused a slight decrease in wheat yield. However, there was no significant difference in wheat yield between SCF and BCF, with no significant 'season × treatment' interactions observed. Over the ten-year observation period, rice yields were found to be greatly influenced by air temperature and precipitation, whereas wheat yields were more dependent on precipitation. In terms of GHG emissions, SCF increased annual methane (CH 4) emissions by 144 % but reduced annual nitrous oxide (N 2 O) emissions by 40 %, resulting in an 80 % increase in annual global warming potential (GWP) compared with CF. On the other hand, BCF reduced CH 4 and N 2 O emissions by 58 % and 25 %, respectively, relative to SCF, in the rice season. Despite slightly higher N 2 O emissions in the wheat season, BCF reduced the annual GWP by 51 %, relative to SCF. Additionally, the relative CH 4 emissions of SCF/CF and BCF/CF decreased over time, with BCF showing lower CH 4 emissions than CF after five years. Overall, the findings suggest that straw carbonization into biochar before soil incorporation could be a promising approach to mitigating GHG emissions and maintaining crop yields compared with incorporating straw directly into the soil in the rice-based rice-wheat rotation systems. • SCF and BCF achieved the same rice yield as CF treatment alone. • There was no significant difference in wheat yield between SCF and BCF. • SCF increased annual GWP by 80 % compared with CF. • BCF decreased annual GWP by 12 % relative to CF and by 51 % compared with SCF. • SCF/CF and BCF/CF ratio in CH 4 emissions decreased over the ten years. [ABSTRACT FROM AUTHOR]

On 20 July 2021, an extraordinary rainfall event occurred in Henan Province, China, resulting in heavy waterlogging, flooding, and hundreds of fatalities and causing considerable property damage. Because the damaged region was a major grain-producing region of China, assessing crop food production losses following this event is very important. Because the crop rotation production system is utilized in the region to accommodate two crops per year, it is very valuable to accurately identify the types of crops affected by the event and to assess the crop production losses separately; however, the results obtained using these methods are still inadequate. In this study, we used China's first commercial synthetic aperture radar (SAR) data source, named Hisea-1, together with other open-source and widely used remote sensing data (Sentinel-1 and Sentinel 2), to monitor this catastrophic flood. Both the modified normalized difference water index (MNDWI) and Sentinel-1 dual-polarized water index (SDWI) were calculated, and an unsupervised classification (k-means) method was adopted for rapid water body extraction. Based on time-series datasets synthesized from multiple sources, we obtained four flooding characteristics, including the flooded area, flood duration, and start and end times of flooding. Then, according to these characteristics, we conducted a more precise analysis of the damages to flooded farmlands. We used the Google Earth Engine (GEE) platform to obtain normalized difference vegetation index (NDVI) time-series data for the disaster year and normal years and overlaid the flooded areas to extract the effects of flooding on crop species. According to the statistics from previous years, we calculated the areas and types of damaged crops and the yield reduction amounts. Our results showed that (1) the study area endured two floods in July and September of 2021; (2) the maximum areas affected by these two flooding events were 380.2 km2 and 215.6 km2, respectively; (3) the floods significantly affected winter wheat and summer grain (maize or soybean), affecting areas of 106.4 km2 and 263.3 km2, respectively; and (4) the crop production reductions in the affected area were 18,708 t for winter wheat and 160,000 t for maize or soybean. These findings indicate that the temporal-dimension information, as opposed to the traditional use of the affected area and the yield per unit area when estimating food losses, is very important for accurately estimating damaged crop types and yield reductions. Time-series remote sensing data, especially SAR remote sensing data, which have the advantage of penetrating clouds and rain, play an important role in remotely sensed disaster monitoring. Hisea-1 data, with a high spatial resolution and first flood-monitoring capabilities, show their value in this study and have the potential for increased usage in further studies, such as urban flooding research. As such, the approach proposed herein is worth expanding to other applications, such as studies of water resource management and lake/wetland hydrological changes. [ABSTRACT FROM AUTHOR]

Straw returning has been one of the most important practices in agricultural management. At the same time, crop diseases, in this case, have been always concerned in China. It is a high demand to clarify the effect of straw returning on the prevalence of diseases of main grain crops. In this study, a meta-analysis was conducted to determine the overall impact of straw returning on the occurrence of the main grain crop diseases. The key factors were also evaluated in response to various environmental factors and agronomic interventions. The data was collected from the published studies before December, 2021. The effective data was selected from the works of literature including: 1) the experiments were conducted in the croplands of China, and 2) the same experiment needed to include the paired treatment and control group. The treatment group was the straw returning to the field, and the control group was no straw returning. The rest experimental conditions of the treatment and control group were strictly consistent, except for whether the straw returned to the field or not. 3) The collected articles contained the incidence rate or disease index data. 4) The crops and returned straw were set as the main food crops rice, wheat, and maize. A total of 369 data sets were obtained to classify, according to the environmental conditions and agricultural management measures. Specifically, the environmental conditions included the climate type, soil pH, and soil organic matter (SOM). Agricultural management measures included the land use type, crop type, straw type, straw returning amount, and initial C/N. The results showed that the straw returning to the field significantly increased the incidence rate and disease index of the main grain crops, indicating an increase of 9.5% and 12.2%, respectively (P<0.05). There was a most serious increase in the virus and soil-borne diseases. Different environmental conditions and agricultural management practices presented a significant impact on the occurrence of major grain crop diseases under straw returning. Among them, the diseases of returning farmland decreased significantly in the subtropical monsoon climate, whereas, there was an increase in the temperate monsoon climate. Returning rice straw to the paddy field was beneficial to the reduction of the diseases. The disease increased significantly in the dry land, especially the wheat-corn rotation. The disease in the slightly acidic soil was lower than that in the slightly alkaline soil. In addition, the occurrence of diseases significantly increased under the conditions of soil organic matter (SOM), the straw returning amount, and the initial C/N were greater than 15 g/kg, 7 000 kg/hm², and 15, respectively. The linear analysis demonstrated that there was a strong negative correlation of the annual precipitation and organic matter content with the occurrence of straw-returning disease, whereas, the initial C/N and soil pH presented a substantial positive correlation. Therefore, straw returning to the paddy fields and acidic soil cultivation greatly contribute to the fewer diseases in China with the high annual average rainfall and warmth. At the same time, a better way is to raise the initial application rate of nitrogen fertilizer. [ABSTRACT FROM AUTHOR]

The summer maize-winter barley (or wheat) rotation system is a conventional farming method in coastal areas of east China. However, researchers have paid little attention to the increasing soil degradation after successive crop rotation in coastal saline agriculture. In the current study, a two-year field experiment was conducted to investigate the changes in soil physio-chemical properties and crop grain yields under the maize-barley rotation system. Wheat straw derived biochar (BC) was applied to topsoil (0~20 cm) at four different rates (0, 7.5, 15 and 30 Mg ha−1) before summer maize cultivation, and no biochar was added in the cultivation of the winter barley. Bulk density (BD), water holding capacity (WHC), water stable aggregate (WSA), soil electrical conductivity (EC), pH (1:5 water w/v) and soil organic carbon (SOC), at the harvesting time of maize and barley, were analyzed. The application of biochar increased WHC and macro-aggregate (>2 mm) content after barley harvest. Soil EC was mainly affected by the rain during maize cultivation and increased only slightly under BC treatments. However, no difference in EC was found among all treatments after barley harvest. The application of BC at 30 Mg ha−1 increased the maize yield by 66% but produced no difference in the barley yield. We concluded that biochar could be an effective option to mitigate soil degradation and improve crop productivity in coastal saline agriculture. [ABSTRACT FROM AUTHOR]