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The effects of fallow season water and straw management on methane (CH4) emissions during the fallow season and the subsequent rice-growing season are rarely reported, and the underlying microbial mechanisms remain unclear. A field experiment was conducted with four treatments: (1) fields flooded in both the fallow and rice seasons (FF), (2) fields drained in the fallow season and flooded in the rice season (DF), (3) FF with straw retention (FFS), and (4) DF with straw retention (DFS). The CH4 emissions in fields under different water and straw treatments were monitored using the static closed chamber method. Methanogenic and methanotrophic communities in these fields were examined using terminal restriction fragment length polymorphism (T-RFLP) analysis based on the mcrA gene and pmoA gene encoding methyl coenzyme M reductase and particulate methane monooxygenase, respectively. The results showed that CH4 emissions were significantly affected by water management, straw retention, season, and their interactions. Over 80% of CH4 emissions occurred during the rice season. Field drainage during the fallow season reduced CH4 emissions by 47.0% and 53.8% with and without straw during the rice season, respectively. Water management altered the abundance and composition of methanogens and methanotrophs, whereas the effects of straw retention were less pronounced. The quantitative polymerase chain reaction (qPCR) assay revealed that field drainage in the fallow season decreased the mcrA gene abundance by 30.0% and 23.2% with and without straw in rice season, respectively, and increased the pmoA gene abundance by 108.9% and 213.7% with and without straw in rice season, respectively. CH4 flux was significantly positively associated with mcrA gene copy number and the ratio of mcrA to pmoA gene copy number, whereas it was significantly negatively correlated with the pmoA gene copy number. Results indicated that fallow drainage greatly decreased CH4 emission not only during the fallow season but also during the subsequent rice season by altering the community composition of methanogens and methanotrophs. These findings provide scientific insight into the role of water and straw management in controlling CH4 emissions through microbial community dynamics. [ABSTRACT FROM AUTHOR]

Purpose: To clarify the effects of maize straw retention combined with reduced fertilization and urease/nitrification inhibitors on the accumulation and leaching potential of mineral N in the deep soil profile of no-tillage agroecosystem. Methods: A 15N-tracing micro-plot experiment was conducted with four treatments (NPK, traditional NPK fertilization; NPKS, NPK with maize straw retention; RNPKS, NPKS with 20% fertilizer-N reduction; and RNPKSI, RNPKS with inhibitors application) in the Mollisol of Northeast China. We analyzed fertilizer-N transformation dynamics in different soil N pools, quantified the fertilizer N use efficiency in crops, and evaluated fertilizer-derived nitrate leaching losses throughout the complete maize growing period. Results: Our analyses revealed that, compared to the NPK treatment, NPKS, RNPKS, and RNPKSI remarkably reduced the accumulation of urea-derived mineral-N during maize seedling stage by enhancing the transformation of urea-N into fixed NH4+-N and organic-N pools, both of which could be quickly released for maize uptake following the extension of crop growth periods. At the maize ripening stage, soil NO3−-N and 15N-labeled urea-derived NO3−-N, which migrated vertically to a depth of 80–100 cm, were significantly reduced by treatments of RNPKS and RNPKSI without minimizing crop yields when compared with NPK. Conclusion: Our results suggest that combining maize straw retention with reduced fertilization and the application of urease/nitrification inhibitors can be efficient management practices for lowering urea N leaching risk, improving N use efficiency, and maintaining or even increasing crop yields by enhancing soil N retention and supply in the croplands of Northeast China. [ABSTRACT FROM AUTHOR]

Cereal + legume rotation is an integrated system that facilitates soil fertility and sustainable agricultural production. However, research on the management compatibility affecting soil physico-chemical properties yields overall agro-ecosystem sustainability, but profitability is lacking, especially under straw retention and potential reductions in fertilizer application. An 11-year field experiment investigated three treatments: no straw retention + traditional mineral fertilization (TNS), straw retention + traditional mineral fertilization (TS), and straw retention + reduced mineral fertilization (DS). Compared with TNS, TS significantly improved soil physico-chemical properties, including macro-aggregates (R > 0.25 mm), porosity, field water capacity (FWC), soil organic carbon (SOC) storage, total nitrogen storage, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) by 17.3%, 3.2%, 13.0%, 5.5%, 3.2%, 15.5%, and 13.8%, respectively. TS also significantly increased total (wheat + soybean) yields (TYs), economic profits, and emergy sustainability index (ESI) by 15.8%, 25.0%, 3.7 times that of TNS, respectively. Surprisingly, compared with TS, DS further significantly improved R > 0.25 mm, porosity, FWC, SOC storage, MBC, MBN, TY, economic profits, and ESI by 11.4%, 1.5%, 6.1%, 3.0%, 10.6%, 7.2%, 5.7%, 11.1%, and 36.5%, respectively. Overall, retaining straw with reduced fertilization enhances soil properties, yields, and emergy sustainability in wheat–soybean rotation systems. [ABSTRACT FROM AUTHOR]

Straw from no-till cropping systems, in addition to increasing the soil organic matter content, may also impede the movement of applied herbicides into the soil and, thus, alter the behavior and fate of these compounds in the environment. Rain or irrigation before or after an herbicide treatment can either help or hinder its movement through the straw, influencing weed control. Our objective was to develop a system for herbicide application and rain simulation, enabling the evaluation of the movement of various herbicides either in dry or wet straw under different rainfall volumes (25, 50, 75, and 100 mm). The amount of the applied herbicides that moved through the straw were collected and measured using a liquid chromatograph with a tandem mass spectrometry system (LC-MS/MS). Measurements obtained with the developed system showed a high herbicide treatment uniformity across all replications. The movement of the active ingredients through the straw showed variability that was a function of the applied herbicide, ranging from 17% to 99%. In wet straw, the collected herbicide remained constant from 50 to 100 mm of simulated rainfall. For the wet straw, the decreasing percentages of the herbicide movement through straw to the soil were sulfentrazone (99%), atrazine and diuron (91% each), hexazinone (84%), fomesafen (80.4%), indaziflam (79%), glyphosate (63%), haloxyfop-p-methyl (45%), and S-metolachlor (27%). On the dry straw, the decreasing percentages of the herbicide movement were fomesafen (88%), sulfentrazone (74%), atrazine (69.4%), hexazinone (69%), diuron (68.4%), glyphosate (48%), indaziflam (34.4%), S-metolachlor (22%), and haloxyfop-p-methyl (18%). Overall, herbicide movement was higher in wet straw (with a previous 25 mm simulated rainfall layer) than in dry straw. Some herbicides, like haloxyfop-p-methyl and indaziflam, exhibited over 50% higher movement in wet straw than dry straw after 100 mm of simulated rain. The developed system can be adapted for various uses, serving as a valuable tool to evaluate the behavior of hazardous substances in different agricultural and environmental scenarios.

The effects of fallow season water and straw management on methane (CH4) emissions during the fallow season and the subsequent rice-growing season are rarely reported, and the underlying microbial mechanisms remain unclear. A field experiment was conducted with four treatments: (1) fields flooded in both the fallow and rice seasons (FF), (2) fields drained in the fallow season and flooded in the rice season (DF), (3) FF with straw retention (FFS), and (4) DF with straw retention (DFS). The CH4 emissions in fields under different water and straw treatments were monitored using the static closed chamber method. Methanogenic and methanotrophic communities in these fields were examined using terminal restriction fragment length polymorphism (T-RFLP) analysis based on the mcrA gene and pmoA gene encoding methyl coenzyme M reductase and particulate methane monooxygenase, respectively. The results showed that CH4 emissions were significantly affected by water management, straw retention, season, and their interactions. Over 80% of CH4 emissions occurred during the rice season. Field drainage during the fallow season reduced CH4 emissions by 47.0% and 53.8% with and without straw during the rice season, respectively. Water management altered the abundance and composition of methanogens and methanotrophs, whereas the effects of straw retention were less pronounced. The quantitative polymerase chain reaction (qPCR) assay revealed that field drainage in the fallow season decreased the mcrA gene abundance by 30.0% and 23.2% with and without straw in rice season, respectively, and increased the pmoA gene abundance by 108.9% and 213.7% with and without straw in rice season, respectively. CH4 flux was significantly positively associated with mcrA gene copy number and the ratio of mcrA to pmoA gene copy number, whereas it was significantly negatively correlated with the pmoA gene copy number. Results indicated that fallow drainage greatly decreased CH4 emission not only during the fallow season but also during the subsequent rice season by altering the community composition of methanogens and methanotrophs. These findings provide scientific insight into the role of water and straw management in controlling CH4 emissions through microbial community dynamics.

Straw from no-till cropping systems, in addition to increasing the soil organic matter content, may also impede the movement of applied herbicides into the soil and, thus, alter the behavior and fate of these compounds in the environment. Rain or irrigation before or after an herbicide treatment can either help or hinder its movement through the straw, influencing weed control. Our objective was to develop a system for herbicide application and rain simulation, enabling the evaluation of the movement of various herbicides either in dry or wet straw under different rainfall volumes (25, 50, 75, and 100 mm). The amount of the applied herbicides that moved through the straw were collected and measured using a liquid chromatograph with a tandem mass spectrometry system (LC-MS/MS). Measurements obtained with the developed system showed a high herbicide treatment uniformity across all replications. The movement of the active ingredients through the straw showed variability that was a function of the applied herbicide, ranging from 17% to 99%. In wet straw, the collected herbicide remained constant from 50 to 100 mm of simulated rainfall. For the wet straw, the decreasing percentages of the herbicide movement through straw to the soil were sulfentrazone (99%), atrazine and diuron (91% each), hexazinone (84%), fomesafen (80.4%), indaziflam (79%), glyphosate (63%), haloxyfop-p-methyl (45%), and S-metolachlor (27%). On the dry straw, the decreasing percentages of the herbicide movement were fomesafen (88%), sulfentrazone (74%), atrazine (69.4%), hexazinone (69%), diuron (68.4%), glyphosate (48%), indaziflam (34.4%), S-metolachlor (22%), and haloxyfop-p-methyl (18%). Overall, herbicide movement was higher in wet straw (with a previous 25 mm simulated rainfall layer) than in dry straw. Some herbicides, like haloxyfop-p-methyl and indaziflam, exhibited over 50% higher movement in wet straw than dry straw after 100 mm of simulated rain. The developed system can be adapted for various uses, serving as a valuable tool to evaluate the behavior of hazardous substances in different agricultural and environmental scenarios. [ABSTRACT FROM AUTHOR]

Purpose: Saline sodic soils pose challenges for crop growth due to their high soil salinity, poor structure, and low nutrient content and effectiveness. As a result, there has been increasing interest in using straw return to the field as a means to enhance productivity. However, the impact of straw return and nitrogen fertilization on soil aggregates and nutrient dynamics in saline sodic soils has not been fully understood yet. Methods: The present study conducted a 3-year positional experiment to examine the effects of straw return (S0: 0, S1: 7 t ha−1) and nitrogen fertilization (N0: 0, N1: 150, N2: 250, and N3: 350 kg ha−1) on bulk density (BD), aggregate distribution, nutrient dynamics, and rice yield. Results: Straw return to the field promoted the transformation of aggregates into larger ones, resulting in increased aggregate stability. Additionally, it significantly reduced the BD by 8.5 to 10% and increased the soil organic carbon (SOC), nitrogen (N), phosphorus (P), and potassium (K) content of the aggregates. The 0.25–2 mm aggregates were found to be the major contributors to fertility enhancement. There were no significant differences in the structure of the aggregates and the nutrient levels between the N2 and N3 treatments. Straw return led to a significant increase in rice yield by 20.90 to 27.57%. However, the differences between the S1N2 and S1N3 treatments were not significant, indicating that S1N2 had better benefits. Regression analysis revealed that the optimum nitrogen application rate tended to decrease with the increase in years of straw return. Conclusion: The incorporation of straw and optimal nitrogen (quantity) into saline sodic soils can enhance soil structure and aggregate nutrients, particularly in 0.25–2 mm aggregates. This agronomic measure is viable in improving soil productivity which ultimately increases rice yield. [ABSTRACT FROM AUTHOR]

Cereal + legume rotation is an integrated system that facilitates soil fertility and sustainable agricultural production. However, research on the management compatibility affecting soil physico-chemical properties yields overall agro-ecosystem sustainability, but profitability is lacking, especially under straw retention and potential reductions in fertilizer application. An 11-year field experiment investigated three treatments: no straw retention + traditional mineral fertilization (TNS), straw retention + traditional mineral fertilization (TS), and straw retention + reduced mineral fertilization (DS). Compared with TNS, TS significantly improved soil physico-chemical properties, including macro-aggregates (R > 0.25 mm), porosity, field water capacity (FWC), soil organic carbon (SOC) storage, total nitrogen storage, microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) by 17.3%, 3.2%, 13.0%, 5.5%, 3.2%, 15.5%, and 13.8%, respectively. TS also significantly increased total (wheat + soybean) yields (TYs), economic profits, and emergy sustainability index (ESI) by 15.8%, 25.0%, 3.7 times that of TNS, respectively. Surprisingly, compared with TS, DS further significantly improved R > 0.25 mm, porosity, FWC, SOC storage, MBC, MBN, TY, economic profits, and ESI by 11.4%, 1.5%, 6.1%, 3.0%, 10.6%, 7.2%, 5.7%, 11.1%, and 36.5%, respectively. Overall, retaining straw with reduced fertilization enhances soil properties, yields, and emergy sustainability in wheat–soybean rotation systems.

Crop straw retention in the rice-based rotation cropland has been widely accepted as an effective method to improve soil quality in China. Rice–wheat rotation cropland is one the most prevalent rice-based rotation patterns, where it only exploits a small proportion of the total agricultural land yet feeds the majority of the Chinese population. Previous studies indicated that the incorporation of fore-rotating crop straw can effectively facilitate soil carbon sequestration in rice paddy fields. However, the application of crop straw may increase methane (CH4) emissions from rice paddies due to the anaerobic soil condition. To mitigate CH4 emissions from rice paddies while still preserving their soil carbon sequestration ability, a field experiment was conducted in the 2012–2016 rice growing seasons to determine the optimal low-carbon crop straw retention strategy. Five treatments with different wheat straw retention strategies were employed in this study, including non-fertilization and non-straw (Control), conventional fertilization without straw incorporation (CF), conventional fertilization with wheat straw incorporation (FS), slow-release fertilizer combined with wheat straw (SFS), and conventional fertilization with wheat-straw-derived biochar (FB). The results indicated that FS, SFS, and FB treatments significantly increased soil carbon sequestration in comparison with CF treatment. However, the increment of soil carbon sequestration was offset by raw wheat straw induced excess CH4 emissions under FS and SFS treatments. In contrast, the application of wheat-straw-derived biochar significantly promoted soil carbon sequestration, but showed no significant effect on CH4 emissions. Collectively, to the farmers, who aim to achieve agricultural carbon neutrality, the application of straw-derived biochar is worthy of consideration in rice cultivation processes. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Application of crop residues and chemical nitrogen (N) fertilizer is a conventional practice for achieving high yield in a rice system. However, the fallacious combination of N fertilizers with crop straw not only significantly reduces the N use efficiencies (NUEs) but also leads to serious environmental problems. The present study employed five treatments including no N fertilization and no straw incorporation (ck), N fertilization incorporation only (S0), N fertilization with 40% straw (S40), N fertilization with 60% straw (S60), and N fertilization with 100% straw (S100) to improve N use efficiency as well as reduced Cd distribution in rice. The crop yields were largely enhanced by fertilization ranging from 13 to 52% over the straw addition treatments. Compared with ck, N fertilizer input significantly decreased soil pH, while DOC contents were raised in response to straw amendment, reaching the highest in S60 and S100 treatments, respectively. Moreover, straw addition substantially impacted the Cd accumulation and altered the bacterial community structure. The soil NH4+-N concentration under S0 performed the maximum in yellow soil, while the minimum in black soil compared to straw-incorporated pots. In addition, the soil NO3−-N concentration in straw-incorporated plots tended to be higher than that in straw-removed plots in both soils, indicating that crop straw triggering the N mineralization was associated with native soil N condition. Furthermore, the NUE increased with 15 N uptake in the plant, and the residual 15 N in soil was increased by 26.8% with straw addition across four straw application rates. Overall, our study highlights the trade-offs between straw incorporation with N fertilizer in eliminating potential Cd toxicity, increasing fertilizer-N use efficiencies and help to provide a feasible agricultural management. [ABSTRACT FROM AUTHOR]

Sugarcane straw returned to the field has rapidly increased due to the bane on straw burning in China. Straw returning of new sugarcane cultivars has been practiced in the fields. Still, its response has not been explored on soil functionality, microbial community and yield of different sugarcane cultivars. Therefore, a comparison was made between an old sugarcane cultivar ROC22 and a new sugarcane cultivar Zhongzhe9 (Z9). The experimental treatments were: without (R, Z), with straw of the same cultivar (RR, ZZ), and with straw of different cultivars (RZ, ZR). Straw returning improved the contents of soil total nitrogen (TN by 73.21%), nitrate nitrogen (NO3 --N by 119.61%), soil organic carbon (SOC by 20.16%), and available potassium (AK by 90.65%) at the jointing stage and were not significant at the seedling stage. The contents of NO3 --N was 31.94 and 29.58%, available phosphorus (AP 53.21 and 27.19%), and available potassium (AK 42.43 and 11.92%) in RR and ZZ were more than in RZ and ZR. Straw returning with the same cultivar (RR, ZZ) significantly increased the richness and diversity of the rhizosphere microbial community. The microbial diversity of cultivar Z9 (treatment Z) was greater than that of cultivar ROC22 (Treatment R). In the rhizosphere, the relative abundance of beneficial microorganisms Gemmatimonadaceae, Trechispora, Streptomyces, Chaetomium, etc., increased after the straw returned. Sugarcane straw enhanced the activity of Pseudomonas and Aspergillus and thus increased the yield of sugarcane., The richness and diversity of the rhizosphere microbial community of Z9 increased at maturity. In ROC22, bacterial diversity increased, and fungal diversity decreased. These findings collectively suggested that the impact of Z9 straw returning was more beneficial than ROC22 on the activity of rhizosphere microorganism's soil functionality and sugarcane production. [ABSTRACT FROM AUTHOR]

The return of straw is a widely used agricultural practice for increasing the soil organic carbon (SOC) content and improving soil structure in Mollisols, owing to the decline caused by continuous high-intensity tillage. We conducted a field experiment where corn straw was continuously returned for 10 years to investigate effects of the straw on the size distribution and stability of soil aggregates and on SOC density fractions. The treatments were no straw return (CK) and four rates of straw return: 6000 kg hm−2 (S1), 9000 kg hm−2 (S2), 12,000 kg hm−2 (S3), and 15,000 kg hm−2 (S4). SOC contents after straw return for bulk soil, a free light fraction (F-LF), an occluded light fraction (O-LF), and a heavy fraction (HF) were significantly higher by 27.0, 644.3, 720.0, and 69.2%, respectively, in S4 than CK. The contents of F-LF, O-LF, and HF in aggregates >2.00 mm were significantly higher by 194.2, 162.1, and 35.8%, respectively, in S4 than CK. Structural equation modeling indicated that SOC contents and aggregates >0.25 mm were directly correlated with the amount of straw returned. We conclude that returning 15,000 kg m−2 of straw would be an effective agronomic practice to restore Mollisol fertility. [ABSTRACT FROM AUTHOR]

Straw retention and wheat-soybean rotation play critical role in maintaining soil quality. However, the correlation between bacterial diversity and community structure, and soil nutrients is unknown, and a systematic understanding of their responses to straw retention is lacking. In the field experiment, the straw retention treatments included no straw (NS), half straw (HS), and total straw (TS) retention during long-term wheat-soybean rotation. The mean contents of soil total nitrogen (TN), nitrate-N (NO3−-N), and microbial biomass nitrogen (MBN) increased by 15.06%, 21.10%, and 38.23%, respectively, with straw retention relative to NS, while that of ammonium-N (NH4+-N) reduced by 3.68%. The concentration of carbon components increased as straw retention increased. The levels of soil dissolved organic carbon (DOC), microbial biomass carbon (MBC), and soil organic carbon (SOC) increased by 4.34%, 7.63%, and 9.34%, respectively, with straw retention relative to NS. Soil bacterial alpha diversity was reduced with straw retention. Soil pH and nutrient content were identified as the main factors affecting the soil microbial diversity and structure at the phylum level. Accordingly, straw retention and soybean-wheat rotation enable sustainable agriculture in the dryland of northern China. [ABSTRACT FROM AUTHOR]

Crop straw retention in the rice-based rotation cropland has been widely accepted as an effective method to improve soil quality in China. Rice–wheat rotation cropland is one the most prevalent rice-based rotation patterns, where it only exploits a small proportion of the total agricultural land yet feeds the majority of the Chinese population. Previous studies indicated that the incorporation of fore-rotating crop straw can effectively facilitate soil carbon sequestration in rice paddy fields. However, the application of crop straw may increase methane (CH4) emissions from rice paddies due to the anaerobic soil condition. To mitigate CH4 emissions from rice paddies while still preserving their soil carbon sequestration ability, a field experiment was conducted in the 2012–2016 rice growing seasons to determine the optimal low-carbon crop straw retention strategy. Five treatments with different wheat straw retention strategies were employed in this study, including non-fertilization and non-straw (Control), conventional fertilization without straw incorporation (CF), conventional fertilization with wheat straw incorporation (FS), slow-release fertilizer combined with wheat straw (SFS), and conventional fertilization with wheat-straw-derived biochar (FB). The results indicated that FS, SFS, and FB treatments significantly increased soil carbon sequestration in comparison with CF treatment. However, the increment of soil carbon sequestration was offset by raw wheat straw induced excess CH4 emissions under FS and SFS treatments. In contrast, the application of wheat-straw-derived biochar significantly promoted soil carbon sequestration, but showed no significant effect on CH4 emissions. Collectively, to the farmers, who aim to achieve agricultural carbon neutrality, the application of straw-derived biochar is worthy of consideration in rice cultivation processes.

Straw retention has been widely implemented to increase soil organic carbon (SOC) sequestration and greenhouse gas (GHG) mitigation for global agriculture. However, the combined effects of long-term straw retention on crop production, SOC sequestration and GHG emissions response to climate change remain unknown. Two nearby wheat–maize rotation field experiments in the North China Plain, combined with local weather, soil and agronomic measurements, were used to evaluate the applicability of the SPACSYS model. The model was then applied to assess the response of crop yield, SOC storage and nitrous oxide (N 2 O) emissions to three nitrogen fertilizer application levels (100, 200, 400 kg N ha−1) and three representative concentration pathway scenarios (RCP2.6, RCP4.5 and RCP8.5) under straw retention for the wheat–maize rotation systems during 2021–2100. In general, the model was reasonably accurate with R 2 and model efficiency (EF) ranging from 0.25 to 0.96 and 0.32–0.94, respectively. Climate change decreased wheat yield by 4–39%, while maize showed a slight increase (3%) under RCP2.6 and a decrease of 1–15% under RCP4.5 and RCP8.5. The SOC storage in the 0–20 cm soil increased at a rate of 73–195 kg C ha−1 yr−1 but decreased within the upper 1 m soil at 280–390 kg C ha−1 yr−1. Climate change reduced the positive effect of SOC sequestration except in RCP2.6 and stimulated substantial N 2 O emissions ranging from 1–7.5 to 2.9–23.2 kg N ha−1 yr−1, consequently, the global warming potential increased from –79–2555 to 548–9357 kg CO 2 -eq ha−1 yr−1 under various N fertilizer application levels. This study reveals that the negative feedback under climate change with modelling approach, and extensive efforts are needed to make adaptations to ensure food production and reduce GHG emissions in the future. [Display omitted] • Climate warming led to the decline of wheat and maize yield except under RCP2.6. • Negative feedback on SOC storage was found under RCP4.5 and RCP8.5. • The SOC storage within 0–1 m soil depth declined under climate warming. • The N 2 O emissions were strongly intensified by climate warming. [ABSTRACT FROM AUTHOR]

Inappropriate farm management practices can lead to increased agricultural inputs and changes in atmospheric greenhouse gas (GHG) emissions, impacting climate change. This study was initiated in 2012 to assess the potential for straw retention to mitigate the negative environmental impact of various cropping systems on the Songnen Plain using the life cycle assessment (LCA) method combined with field survey data. Straw retention (STR) and straw removal (STM) treatments were established in continuous corn (CC) and corn-soybean rotation (CS) systems in a split-plot experiment. The effects of straw retention on the carbon footprint (CF) of cropland under different cropping systems were compared. The CF under CC was 2434–2707 kg CO2 ha−1 year−1, 49–57% higher than that under CS. Nitrogen fertilizer produced the most CO2, accounting for 66–80% of the CF. The carbon balances of the CC and CS systems with STR were positive, with annual carbon sequestrations of 9633 and 2716 kg CO2 ha−1 year−1, respectively. The carbon balance (CB) of CC-STR was 255% higher than that of CS-STR. This study demonstrates that STR under CC cultivation is an environmentally friendly practice for agricultural production, can help achieve high-yield and low-carbon production in rainfed cropland, and can support the sustainable development of grain production in Northeast China. [ABSTRACT FROM AUTHOR]

Crop straw retention is a strongly recommended practice for sustainable agricultural production in China. However, a comprehensive analysis of straw retention effects on crop yield, N2O and CH4 emissions, net greenhouse gas (NGHG), and net greenhouse gas intensity (NGHGI) and their response to various external influence factors, including location/climatic conditions, soil properties, and field management practices, in a national scale were easily ignored. Based on the collected published literatures, we found that straw retention improved crop yield and N2O and CH4 emissions by 4.7% (−4.6 to 25.8%), 18.3% (−26.6 to 57.6%), and 21.0% (−49.0 to 214.5%) in contrast with no-straw retention. For different external conditions, crop yield was increased by 15.9% in temperate zone and 10.7% in upland soils with straw retention. N2O emissions which correspond to the above conditions were enhanced by 42.2% and 18.8%, while CH4 emissions were restrained by 49.0% in temperate zone. Negligible changes in crop yield and N2O emissions were observed for subtropical zone or paddy soils, but with increase in CH4 emissions. Additionally, straw retention enhanced NGHG and NGHGI by 20.7% and 15.4% on average regardless of various external conditions, respectively. However, NGHG was reduced under conditions of straw retention in temperature or mulching to field. Straw retention under appropriate site-specially conditions simultaneously safeguard food security and slightly increase environmental effects. [ABSTRACT FROM AUTHOR]

The return of straw is a widely used agricultural practice for increasing the soil organic carbon (SOC) content and improving soil structure in Mollisols, owing to the decline caused by continuous high-intensity tillage. We conducted a field experiment where corn straw was continuously returned for 10 years to investigate effects of the straw on the size distribution and stability of soil aggregates and on SOC density fractions. The treatments were no straw return (CK) and four rates of straw return: 6000 kg hm−2 (S1), 9000 kg hm−2 (S2), 12,000 kg hm−2 (S3), and 15,000 kg hm−2 (S4). SOC contents after straw return for bulk soil, a free light fraction (F-LF), an occluded light fraction (O-LF), and a heavy fraction (HF) were significantly higher by 27.0, 644.3, 720.0, and 69.2%, respectively, in S4 than CK. The contents of F-LF, O-LF, and HF in aggregates >2.00 mm were significantly higher by 194.2, 162.1, and 35.8%, respectively, in S4 than CK. Structural equation modeling indicated that SOC contents and aggregates >0.25 mm were directly correlated with the amount of straw returned. We conclude that returning 15,000 kg m−2 of straw would be an effective agronomic practice to restore Mollisol fertility.

Straw retention and wheat-soybean rotation play critical role in maintaining soil quality. However, the correlation between bacterial diversity and community structure, and soil nutrients is unknown, and a systematic understanding of their responses to straw retention is lacking. In the field experiment, the straw retention treatments included no straw (NS), half straw (HS), and total straw (TS) retention during long-term wheat-soybean rotation. The mean contents of soil total nitrogen (TN), nitrate-N (NO3−-N), and microbial biomass nitrogen (MBN) increased by 15.06%, 21.10%, and 38.23%, respectively, with straw retention relative to NS, while that of ammonium-N (NH4+-N) reduced by 3.68%. The concentration of carbon components increased as straw retention increased. The levels of soil dissolved organic carbon (DOC), microbial biomass carbon (MBC), and soil organic carbon (SOC) increased by 4.34%, 7.63%, and 9.34%, respectively, with straw retention relative to NS. Soil bacterial alpha diversity was reduced with straw retention. Soil pH and nutrient content were identified as the main factors affecting the soil microbial diversity and structure at the phylum level. Accordingly, straw retention and soybean-wheat rotation enable sustainable agriculture in the dryland of northern China.

Sugarcane straw may work as a physical barrier for pre-emergent herbicides and interact with their molecules, increasing sorption process. Adjuvants may change herbicides dynamics in the environment and improve their efficiency for weed control. The objective of this work was to evaluate sorption and desorption of pendimethalin alone and in mixture with adjuvant in soil and sugarcane straw. Sorption experiments were performed using pendimethalin alone and in mixture with vegetable oil with herbicide solution concentrations ranging between 2.5 and 40 μg mL−1 for both conditions. Sorption distribution coefficient (Kd) for soil was 18.48 mL g−1 using pendimethalin alone. Kd value was not determined when pendimethalin was in mixture with adjuvant due to the complete retention of the herbicide in the soil regardless of the initial aqueous phase concentration. Sugarcane straw sorption experiment had Kd values corresponding to 355.52 and 27.24 mL g−1 for pendimethalin alone and in mixture with adjuvant, respectively, indicating the addition of vegetable oil may significantly decrease pendimethalin retention in the straw and could improve weed control. Besides all desorption coefficients were higher than the respective sorption coefficients, which means that the sorption process may be considered irreversible. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of straw retention on soil bacterial community structure, microbial function, and biochemical properties were assessed. Terminal restriction fragment length polymorphism (T-RFLP) and community-level physiological profile (CLPP) assays were used to assess the bacteria community structure and microbial function respectively. Treatments included straw removal with conventional tillage (CT), straw retention with conventional tillage (SRCT) and straw retention with no tillage (SRNT). SRCT and SRNT significantly (p < 0.05) increased soil organic carbon by 8.9% and 9.7%, and microbial biomass carbon by 44.7% and 330.8%, respectively, compared with CT. T-RFLP analysis indicated that straw retention had no favourable effect on soil bacterial diversity, and SRCT significantly (p < 0.05) decreased bacterial diversity compared to CT. Among the three treatments, SRNT had the highest activity of urease, invertase, cellulase, and β-glucosidase. SRCT significantly (p < 0.05) increased the activity of invertase and β-glucosidase compared to CT treatment. CLPP analysis showed that microbial functional diversity was significantly (p < 0.05) increased by straw retention. Enzyme activity and microbial functional diversity were not correlated with bacterial diversity. Therefore, according to this study, SRNT is a better farming practice because it improves soil fertility and biological quality. [ABSTRACT FROM AUTHOR]

Crop straw retention to field (CSRF) is a technology to impact the crop yield, soil properties and greenhouse gas (GHG) emission and plays a critical role in sustainable agriculture system. Based on the literatures published, a meta-analysis was performed to evaluate actual impact of CSRF on crop yield, soil properties and GHG emission compared with straw no-retention (NSR). The results indicated that compared with NSR, yield of wheat, maize and rice under CSRF was significantly higher by 4.11, 7.22 and 7.62% respectively; CSRF enhanced the water use efficiency (WUE) and soil organic carbon (SOC) by 14.60 and 7.59%, respectively, reduced the bulk density of 0–20 cm soil layer by 3.06%., while it had no significant effect on the SOC of 20–40 cm; For GHG emissions, the soil emissions of CO2, N2O and CH4 were significantly improved under CSRF by 23.64, 12.21 and 27.34% respectively. Categorically, results on meta-analysis and regression indicated that large variation in crop yield, SOC content and bulk density in 0–20 cm soil layer, WUE and GHG emission under CSRF compared with NSR because of different straw retention mass, retention regions, and crop species. For example, the increased rate of large straw retention mass (LA) on crop yield was the highest. Adoption of CSRF under appropriate site-specific conditions can safeguard China's food security, alleviate soil-related constraints and slightly increase GHG emissions. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Conservation farming practices, such as no-tillage and crop residue retention, have been proposed as sustainable management practices. However, it remains unclear how different tillage practices and rice straw retention affect the soil bacterial community (SBC) and the soil C/N ratio in the long term. The objective of this study was to evaluate changes in SBC composition and abundance and soil properties (e.g., carbon (C), nitrogen (N)) and determine their relationship to the soil C/N ratio under long-term no-tillage and straw retention techniques. This study investigates the effect of a long-term field experiment begun in 2008 and continued until 2019 to measure the response of the SBC and soil properties and their relation to different tillage practices, including no-tillage (NT), no-tillage and straw mulching (NT-SM), conventional tillage (CT), conventional tillage and straw mulching (CT-SM), and conventional tillage and straw retention (CT-SR). Soil samples were collected at depths of 0–5 cm (A), 5–10 cm (B), and 10–20 cm (C) after rice harvesting in the early and late growing seasons in 2018–2019. The Illumina MiSeq sequencing and quantitative polymerase chain reaction (PCR) technology was used to analyze changes in SBC diversity in soil and determined the changes in the soil C/N ratio and their relationship with the SBC diversity. The results showed that the Proteobacteria, Acidobacteria, and Chloroflexi were the dominant phyla in the soil and accounted for 61.26%, 59.39%, and 55.62% of the total bacteria in the A, B, and C soil layers, respectively. The NT treatment increased SBC diversity, the number of operational taxonomic units (OTUs), and the proportion of Proteobacteria across the soil depths. Similarly, straw retention also significantly improved SBC diversity, soil organic C (SOC), total N (TN), soil C/N ratio, and the abundance of Proteobacteria and Acidobacteria in the soil layers A and B. The NT-SM treatment increased the SOC, TN, and soil C/N ratio by 30%, 21%, and 6% in 2018 and by 33, 25% and 7% in 2019, respectively, across the seasons and layers compared to the CT treatment. The NT-SM treatment had the highest soil bacterial diversity index, and the CT-SR treatment had the highest soil bacterial abundance and number of OTUs. The redundancy analysis showed that Acidobacteria were highly positively correlated with the soil C/N ratio. The results demonstrate that conservation tillage practices, i.e., no-tillage and straw retention, increase the SBC diversity and soil C/N ratio, thereby enhancing soil organic C and total N and changing soil microbial ecology. As a result, sustainable crop production and profitable agro-ecosystems are ensured.

Intercropping is considered a promising system for boosting crop productivity. However, intercropping usually requires higher inputs of resources that emit more CO2. It is unclear whether an improved agricultural pattern could relieve this issue and enhance agricultural sustainability in an arid irrigation area. A field experiment using a well-designed agricultural practice was carried out in northwest China; reduced tillage, coupled with wheat straw residue retention measures, was integrated with a strip intercropping pattern. We determined the crop productivity, water use, economic benefits, and carbon emissions (CEs). The wheat-maize intercropping coupled with straw covering (i.e., NTSI treatment), boosted grain yield by 27–38% and 153–160% more than the conventional monoculture of maize and wheat, respectively, and it also increased by 9.9–11.9% over the conventional intercropping treatment. Similarly, this pattern also improved the water use efficiency by 15.4–22.4% in comparison with the conventional monoculture of maize by 45.7–48.3% in comparison with the conventional monoculture of wheat and by 14.7–15.9% in comparison with the conventional intercropping treatment. Meanwhile, NTSI treatment caused 7.4–13.7% and 37.0–47.7% greater solar energy use efficiency than the conventional monoculture of maize and wheat, respectively. Furthermore, the NTSI treatment had a higher net return (NR) by 54–71% and 281–338% and a higher benefit per cubic meter of water (BPW) by 35–51% and 119–147% more than the conventional monoculture of maize and wheat, respectively. Similarly, it increased the NR and BPW by 8–14% and 14–16% in comparison with the conventional intercropping treatment, respectively. An additional feature of the NTSI treatment is that it reduced CEs by 13.4–23.8% and 7.3–17.5% while improving CE efficiency by 62.6–66.9% and 23.2–33.2% more than the conventional monoculture maize and intercropping treatments, respectively. We can draw a conclusion that intercropping maize and wheat, with a straw covering soil surface, can be used to enhance crop production and NRs while effectively lowering CO2 emissions in arid oasis irrigation region.

Intercropping is considered a promising system for boosting crop productivity. However, intercropping usually requires higher inputs of resources that emit more CO2. It is unclear whether an improved agricultural pattern could relieve this issue and enhance agricultural sustainability in an arid irrigation area. A field experiment using a well-designed agricultural practice was carried out in northwest China; reduced tillage, coupled with wheat straw residue retention measures, was integrated with a strip intercropping pattern. We determined the crop productivity, water use, economic benefits, and carbon emissions (CEs). The wheat-maize intercropping coupled with straw covering (i.e., NTSI treatment), boosted grain yield by 27–38% and 153–160% more than the conventional monoculture of maize and wheat, respectively, and it also increased by 9.9–11.9% over the conventional intercropping treatment. Similarly, this pattern also improved the water use efficiency by 15.4–22.4% in comparison with the conventional monoculture of maize by 45.7–48.3% in comparison with the conventional monoculture of wheat and by 14.7–15.9% in comparison with the conventional intercropping treatment. Meanwhile, NTSI treatment caused 7.4–13.7% and 37.0–47.7% greater solar energy use efficiency than the conventional monoculture of maize and wheat, respectively. Furthermore, the NTSI treatment had a higher net return (NR) by 54–71% and 281–338% and a higher benefit per cubic meter of water (BPW) by 35–51% and 119–147% more than the conventional monoculture of maize and wheat, respectively. Similarly, it increased the NR and BPW by 8–14% and 14–16% in comparison with the conventional intercropping treatment, respectively. An additional feature of the NTSI treatment is that it reduced CEs by 13.4–23.8% and 7.3–17.5% while improving CE efficiency by 62.6–66.9% and 23.2–33.2% more than the conventional monoculture maize and intercropping treatments, respectively. We can draw a conclusion that intercropping maize and wheat, with a straw covering soil surface, can be used to enhance crop production and NRs while effectively lowering CO2 emissions in arid oasis irrigation region. [ABSTRACT FROM AUTHOR]

Research the effects of straw retention (SRT) and nitrogen fertilizer on nitrogen concentration in soil solution and yield during the growth period of rice. This study was conducted to explore the variation of nitrogen concentration in soil solution by continuous location plot experiment, pot experiment, and laboratory culture experiment. The results showed that the ammonium N (NH4 + -N), nitrate N (NO3 − -N), and mineral N contents of the soil solution gradually decreased with increasing rice growth. Moreover, the N contents of the soil solution gradually increased with an increasing rate of N fertilizer application; however, increasing the rate of N fertilizer application did not change the effect of SRT on the N content in the soil solution. Comparing SRT with straw removal (SRM), the NH4 + -N in the soil solution increased by 29.08% (0.17 mg L-1) over the rice-growing period; by contrast, the NO3 − -N and mineral N contents decreased by 8.90% (0.47 mg L-1) and 3.02% (0.29 mg L-1), respectively. In the black soil region of Northeast China, SRT reduced the nitrate concentration in the soil solution, and the N contents mineral was lower than that of the straw. Under production conditions, SRT has the trend of increasing rice yield [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the hilly areas of southern China, uplands and paddies are located adjacent to each other. Using rice straw as mulch for upland soil may improve crop production and partially replace chemical fertilizers, which may mitigate N2O emissions. A field experiment was conducted to investigate the potential of rice straw mulching for mitigating N2O emissions and increasing crop production. The treatments included no mulching (CK), 5000 kg ha−1 of straw mulching (SM5), and 10,000 kg ha−1 of straw mulching (SM10). Moreover, all the treatments received equivalent amounts of nitrogen, phosphorus, and potassium from chemical fertilizers plus rice straw. Relative to CK, cumulative N2O emissions decreased by 23.1 and 33.5% with SM5 and SM10, respectively. Significant positive correlations were observed between N2O fluxes and soil water-filled pore space (WPFS) (r2 = 0.495, P < 0.05) and between seasonal cumulative N2O fluxes and the chemical N fertilization rate (r2 = 0.814, P < 0.05). These findings indicate that soil WPFS was the key environmental factor in N2O emissions and that the substitution of chemical nitrogen fertilizer with rice straw was the main driver of N2O mitigation. Relative to CK, the maize yield increased by 16.5 and 29.6% with SM5 and SM10, respectively, which can be attributed primarily to the increases in soil moisture. The chemical fertilizer input could be decreased and N2O emissions could be mitigated through straw mulching, while achieving improved crop yield. This management strategy has great potential, and this study provides an important reference for low-carbon agriculture. [ABSTRACT FROM AUTHOR]

Intercropping is reported to enhance crop production and be a better use of land, thermal radiation and nutrients in many areas around the world. However, intercropping is always yield-advantageous, but consumes more water. Meanwhile, the intercropping advantage is usually attributed to the high inputs of resources, which lead to increased carbon emissions. It is unclear whether developing an improved agricultural production pattern could relieve this situation and enhance farming productivity in water-limited arid areas. A field experiment using an improved system was conducted at an arid oasis region in northwestern China in 2014, 2015, and 2016. No-tillage coupled with two-year plastic film mulching and straw retention measures were integrated into intensified strip intercropping, and the effects on the crop yield, water use, and carbon emissions characteristics were determined. A sustainable evaluation index integrating several key parameters related to yield, water use, and carbon emission was created. We found that a wheat/maize intercropping pattern boosted the grain yield by 12.8 and 131.0% compared to the average yield of maize and wheat monoculture, respectively. The intercropping under no-tillage with straw covering and two-year plastic film mulching treatment (i.e., NTSI2) yielded 17009 kg ha −1 , an increase of 14.9%, in the three studied years compared to an intercropping pattern with conventional treatment (i.e., CTI). The wheat-maize intercrops produced 5.9 and 113.7% more energy yield than monoculture maize and wheat, respectively, and NTSI2 had a 6.6% greater energy yield than CTI. NTSI2 improved the water use efficiency based on the grain and energy yields by 15.5 and 7.1%, respectively, over the CTI treatment. The carbon emissions of wheat/maize intercropping pattern were 18.9% lower than maize monoculture, and NTSI2 treatment reduced carbon emissions over CTI by 14.7%. Compared with maize monoculture, the wheat/maize intercrops had a 27.2% lower water use efficiency based on carbon emissions, and the NTSI2 treatment was reduced by 14.4% compared to CTI. However, wheat/maize intercropping had a greater carbon emission efficiency of 39.9% than monoculture maize, and the NTSI2 treatment was increased by 34.7% in the three studied years than that of CTI. The wheat/maize intercropping pattern achieved the highest evaluation index among the three cropping patterns evaluated, and the NTSI2 treatment had the highest sustainable index among the four intercropping treatments assessed. Therefore, wheat/maize intercropping of no-tillage with two-year plastic film mulching and straw covering is the most sustainable and effective cropping production pattern in arid Oasis regions. [ABSTRACT FROM AUTHOR]

Improving compensation effect of late-maturing crop is a feasible way to increase total productivity of intercropping system. In arid areas, it is unknown whether the compensation can be improved via optimizing management of early-maturing crops. In this study, we developed an improved crop production pattern, i.e., plastic combined with 25–30 cm tall of three straw retention treatments, including straw standing (i.e., NTSS), straw covering (i.e., NTS), or straw incorporated into the soil (i.e., TIS), and one conventional deep tillage treatment without crop straw residue (i.e., CT) for early-maturing wheat in wheat-maize intercropping systems, to determine (i) the compensation effect of dry matter accumulation of intercropped maize after accompanying wheat harvest in different intercropping treatments; (ii) the secondary super-compensation effect (i.e., SCE) of intercropped maize based on dry matter transformation; and (iii) the comprehensive compensation effect of different intercropping systems, in comparison to monoculture maize with conventional treatment (i.e., CTM). The field experiment was conducted in northwestern China from 2009 to 2012. We found that the improved crop production patterns can increase the crop growth rate (i.e., CGR) of intercropped maize after the intercropped wheat was harvested, especially, NTS accelerated the compensation effect of intercropped maize, and shortened the compensation process of the intercropped maize. Straw retention increased contribution rate to grain yield by each organ in maize. Thus the SCE based on contribution to grain yield from leaf increased by 13.7%, increased by 14.9% from stem, and 32.8% from sheath, in comparison with CT treatment; NTS had higher SCE by 10.9%, 11.4%, and 26.2% from leaf, stem, sheath of maize, respectively, than those of NTSS and TIS. These results means that improved systems can improve the grain yield by 73.7% and harvest index by 11.7%, compared with the CTM treatment; NTS was the most productive pattern, boosted the maize grain yield by 16.4% and increased harvest index by 14.8% over intercropping maize with conventional treatment, during the three studied years. We can draw a conclusion that intercropping wheat and maize with straw mulching on the soil surface can be applied as an effective straw management method in improving the super-compensatory effect of late-maturing maize, thus improving total yield in intercropping system in arid oasis areas. [ABSTRACT FROM AUTHOR]

A field experiment was conducted to study the effects of combination of straw incorporation and water management on fluxes of CH4, N2O and soil heterotrophic respiration (Rh) in a paddy field in subtropical central China by using a static opaque chamber/gas chromatography method. Four treatments were set up: two rice straw incorporation rates at 0 (S1) and 6 (S2) t ha−1combined with two water managements of intermittent irrigation (W1, with mid-season drainage) and continuous flooding (W2, without mid-season drainage). The cumulative seasonal CH4emissions for the treatments of S1W2, S2W1 and S2W2 increased significantly by 1.84, 5.47 and 6.63 times, respectively, while seasonal N2O emissions decreased by 0.67, 0.29 and 1.21 times, respectively, as compared to S1W1 treatment. The significant increase in the cumulative Rh for the treatments S1W1, S2W1 and S2W2 were 0.54, 1.35 and 0.52 times, respectively, in comparison with S1W2. On a seasonal basis, both the CO2-equivalents (CO2e) and yield-scaled CO2e (GHGI) of CH4and N2O emissions increased with straw incorporation and continuous flooding, following the order: S2W2>S2W1>S1W2>S1W1. Thus, the practices of in season straw incorporation should be discouraged, while mid-season drainage is recommended in paddy rice production from a point view of reducing greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3) emissions are an important pathway of nitrogen (N) losses in rice paddies. Lime application and straw retention are common practices to enhance soil fertility in acidic soils. However, the interaction of lime and straw application on NH 3 emissions from paddies remain unclear. Here, a factorial experiment was employed to examine the interactive effects of slaked lime (i.e., Ca(OH) 2) and straw retention on NH 3 emissions and NH 3 emission factors (EFs) in a double-cropped rice field. The results showed that compared to unlimed treatments, liming promoted NH 3 emissions and EFs by 98.6% and 90.2% in the early rice growth season, respectively, with increases of 16.3% and 15.7% in the late rice growth season. Relative to straw removal, straw retention increased NH 3 emissions by 52.8% in the early rice growth season but did not alter EFs, while reducing NH 3 emissions by 9.9% and EFs by 25.7% in the late rice growth season. Liming interacted with straw retention to increase NH 3 emissions and EFs in the early rice growth season. Under straw retention, liming promoted NH 3 emissions by 147.7% and EFs by 148.3%, whereas liming raised NH 3 emissions and EFs only by 45.3% and 45.5% under straw removal, respectively. Liming had no significant interactions with straw retention on NH 3 emissions and EFs in the late rice growth season. It is likely that the decomposition extent of straw can alter the response of NH 3 emissions to liming. Thus, NH 3 emission inventories should take into account the interaction of liming and straw retention and its dependence on rice growth seasons in double-cropped rice systems with acidic soils. • Liming alone increased NH 3 emissions and NH 3 emission factors (EFs) in a double-cropped rice field. • Straw retention alone promoted NH 3 emissions in the early rice growth season but reduced them in the late rice growth season. • Liming interacted with straw retention to increase NH 3 emissions and EFs in the early rice growth season. • Liming had no significant interactions with straw retention on NH 3 emissions and EFs in the late rice growth season. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions from agriculture production are predicted to increase as the world's population and demand for food increases. This research assessed the influence of tillage systems on CO, NO and CH fluxes and soil properties in spring wheat-field pea sequence in a rain-fed semi-arid environment. The tillage practices included; conventional tillage with straw removed (T), no-till with straw removed (NT), no-till with straw retention on the soil surface (NTS) and conventional tillage with straw incorporated (TS). Greenhouse gas emissions were monitored during the 2013, 2014 and 2015 cropping seasons using a carbon dioxide analyzer and static chamber-gas chromatography. Although the results showed that all treatments served as sources of atmospheric CO and NO, and a sink of atmospheric CH, CO and NO emissions significantly decreased by 21 and 34 % in NTS sites, and CH uptake increased by 22 % compared with T fields. Soil organic carbon (0-30 cm) increased by 24, 19 and 7 % in NTS compared to T, NT and TS respectively. In addition, the contribution to increase soil organic carbon was much higher under straw retention treatments. T plots significantly increased global warming potential by 37 and 30 % in NO and CH versus NTS soils. NTS increased straw and grain yield compared with straw removal treatments (NT and T), but that had no effect compared with TS treatment. NTS farming practices demonstrated increases in crop productivity and reduced greenhouse gas under dryland cropping systems. [ABSTRACT FROM AUTHOR]

Because of asynchrony between the winter wheat growing season and precipitation, soil water supply is the main factor constraining winter wheat production. Hence, increasing soil water conservation is a crucial approach for improving winter wheat productivity in dryland. A 5-year-long, location-fixed field experiment was conducted to determine the effects of plastic mulch, straw retention, planting legume, and straw-legume on soil water and winter wheat grain yield. In comparison to the control, average rainfall harvest during summer fallow was increased by 9% by plastic mulch and mainly occurred in wet summers, and not affected by straw retention, but respectively decreased by 22% and 17% by planting legume and straw-legume. Average soil water storage at sowing was increased by 5% in plastic mulch and occurred in most summers, as well as also increased by 3% in straw retention but only occurred in one wet summer, and decreased by 5% in both planting legume and straw-legume and occurred in most cases. Average ET was not affected by plastic mulch and straw retention, but respectively decreased by 7% and 5% by planting legume and straw-legume. As a result, plastic mulch caused a 6% increase in the average grain yield of winter wheat, but straw retention, planting legume, and straw-legume decreased it by 8%, 6%, and 5%, respectively. Overall, plastic mulch is a beneficial measure for increasing rainfall harvest during summer fallow and soil water storage at sowing, and preferable for harvesting more grain yield, but the straw retention, planting legume and straw-legume showed hardly any benefit for grain yield of winter wheat in dryland. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is an essential nutrient for proper rice growth, and available P in the soil solution is a direct source of P for rice uptake. In this study, a field experiment (experiment A: straw retention (SRT) treatment versus straw removal (SRM) treatment) exposed to 3 years of continuous SRT and a pot experiment (experiment B: five P levels; SRT and SRM treatments) with different concentrations of applied P fertilizer were conducted to study the effects of SRT and P fertilizer application on the available P concentration in the soil solution during rice growth and on rice yield. SRT decreased the available P concentration in the soil solution, although it did not alter the trend of available P concentration in the soil solution during plant growth. In addition, in the 10-20-day period after transplantation, the available P concentration in the soil solution was high, although it decreased thereafter. The available P concentration in the soil solution increased with the amount of applied P fertilizer, and the rice yield also increased with increasing applications of P fertilizer. The results of experiments A and B showed that SRT had no significant impact on the rice yield; however, continuous observations over a number of years are required to verify the results. [ABSTRACT FROM AUTHOR]

Sugarcane straw returned to the field has rapidly increased due to the bane on straw burning in China. Straw returning of new sugarcane cultivars has been practiced in the fields. Still, its response has not been explored on soil functionality, microbial community and yield of different sugarcane cultivars. Therefore, a comparison was made between an old sugarcane cultivar ROC22 and a new sugarcane cultivar Zhongzhe9 (Z9). The experimental treatments were: without (R, Z), with straw of the same cultivar (RR, ZZ), and with straw of different cultivars (RZ, ZR). Straw returning improved the contents of soil total nitrogen (TN by 73.21%), nitrate nitrogen (NO 3 - N by 119.61%), soil organic carbon (SOC by 20.16%), and available potassium (AK by 90.65%) at the jointing stage and were not significant at the seedling stage. The contents of NO 3 - N was 31.94 and 29.58%, available phosphorus (AP 53.21 and 27.19%), and available potassium (AK 42.43 and 11.92%) in RR and ZZ were more than in RZ and ZR. Straw returning with the same cultivar (RR, ZZ) significantly increased the richness and diversity of the rhizosphere microbial community. The microbial diversity of cultivar Z9 (treatment Z) was greater than that of cultivar ROC22 (Treatment R). In the rhizosphere, the relative abundance of beneficial microorganisms Gemmatimonadaceae, Trechispora, Streptomyces, Chaetomium, etc., increased after the straw returned. Sugarcane straw enhanced the activity of Pseudomonas and Aspergillus and thus increased the yield of sugarcane., The richness and diversity of the rhizosphere microbial community of Z9 increased at maturity. In ROC22, bacterial diversity increased, and fungal diversity decreased. These findings collectively suggested that the impact of Z9 straw returning was more beneficial than ROC22 on the activity of rhizosphere microorganism's soil functionality and sugarcane production., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wang, Qi, Shi, Zhao, Ahmad, Akhtar, Chen, Lian, He and Wen.)

Conservation tillage has been applied in vast semi-arid regions of the Guanzhong Plain, Northwest China. The tillage effects on soil aggregation, organic carbon ( OC) stabilization and grain yield on this plain have not been fully elucidated. A 9-year field experiment was established from 2002 on a silty clay loam soil (Eum-Orthic Anthrosol) growing winter wheat-maize in a double-cropping system. Six conservation tillage treatments were applied by different combinations of rotary tillage ( RT), subsoiling ( SS) and no-till ( NT), with or without finely chopped straw retention. Conventional tillage ( CT) acted as the control. Results showed that in the surface (0-10 cm) soil, the proportion of water-stable aggregates ( WSA) <0.05 mm was 18% less while that for WSA >2 mm was 98% more under NT treatments compared with CT. Additionally, the oxidizable OC content in WSA 0.25-2 mm was 27% greater under NT treatments compared with CT. The OC stocks increased under SS by 17%, RT by 16% and NT by 15% relative to CT. Grain yield (wheat + maize) showed similar increasing trends in all the tillage treatments compared with CT. Both OC stocks and grain yield were larger in treatments with than without straw retentions. These results indicate that NT is beneficial for OC accumulation in WSA but is limited in its ability to improve soil structure in this region. SS plus straw retention (fine-chopped or as a mulch) is an effective practice to improve soil structural stability, OC accumulation and soil productivity of Eum-Orthic Anthrosols in Northwest China. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the effects of tillage and straw returning on soil nutrient and its pools, and soil Cd concentration, and to identify the strategies for rational tillage and remediation of Cd contaminated paddy fields. The experiment was established with no-tillage with straw retention (NTS), rotary tillage with straw incorporation (RTS), conventional plow tillage with straw incorporation (CTS), conventional plow tillage with straw removed (CT) from 2005 to 2013. The results indicated that tillage and rice straw retention had a great impact on soil properties at 0-10 cm soil depth. The soil aeration, and concentrations of soil nutrient and soil Cd increased under CTS, CT, and RTS. Due to the shallow plow layers, soil nutrient pools and the Cd concentration in rice shoot decreased in long-term tilled soil. Under long-term no-tillage, the soil bulk, soil nutrient pools and Cd concentration in rice shoot increased, but concentrations of soil nutrients decreased. In addition, rice straw returning significantly increased the soil nutrient concentrations, cation exchange capacity, depth of plow layer, and soil nutrient pools. However, the Cd in the rice straw was also returned to the soil by rice straw returning, which would not benefit the remediation of soil Cd. Therefore, it is necessary to improve tillage and straw retention practices due to the disadvantages of long-term continuous single tillage method and rice straw returning practices. Some recommended managements (e.g., rotational tillage or subsoiling, reducing straw returning amount, and rotational straw returning) could be good options in enhancing soil fertility and remedying soil pollution. [ABSTRACT FROM AUTHOR]

Climate change significantly impacts the prevailing climatic conditions and crop productivity. Although soil organic carbon (SOC) sequestration can mitigate global climate change, the SOC sequestration capacity and crop production under conservation tillage are unclear. This study assessed the dynamics and relationship between SOC storage and grain yield under conservation tillage over eight years. Four tillage and straw management treatments, including (i) no-tillage with straw retention (NTS, conservation tillage), (ii) conventional tillage with straw retention (CTS), (iii) no-tillage without straw retention (NT), and (iv) conventional tillage without straw retention (CT), were conducted. The results showed that the SOC content and storage in the 0–10 cm soil layer were significantly higher in NTS than in the other treatments. In contrast, SOC content and storage in the 10–30 cm layer were lower in NTS than in CTS (P < 0.05). Overall, the average SOC storage in the 0–30 cm was significantly higher in the straw returning treatment than without straw returning (P < 0.05). Moreover, SOC storage was not significantly different between NTS (35.7 Mg ha−1) and CTS (35.9 Mg ha−1). The wheat yield was lowest under NTS. Furthermore, the yield coefficient of variation under NTS was significantly lower than under CTS (P < 0.05). Maize yield was not significantly different between NTS and CTS. SOC storage in the 0–10 cm soil layer had a quadratic relationship with annual yield. These results indicate that NTS can positively sequester carbon, especially for the surface layer. However, to mitigate climate change and food insecurity, further advancements in NTS technology are required to improve crop yields and carbon sequestration capacity. [Display omitted] • Compared no-till to ploughing with (NTS, CTS) and without (NT, CT) straw returning. • NTS increased SOC content and storage of surface soil (0–10 cm). • SOC storage (0–30 cm) was not significantly different between NTS and CTS. • Temporal variation of wheat yield was significantly lower in NTS than in CTS. • Beyond 16.8 Mg ha−1 SOC surface stock, there was no continuous yield increase. [ABSTRACT FROM AUTHOR]