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Crop residue retention (RR) is a recommended practice in China and globally. However, comprehensive assessment of changes and mechanisms affecting crop production and soil processes with RR and thus identifying systems of sustainable residues management are not widely studied. A national meta‐analysis was conducted to assess changes in 24 indicators (related to soil quality, soil nutrients, crop yield, and environmental impacts) along with their relationships under RR through 4,910 comparisons from 278 publications across China's croplands. Positively, RR significantly increased crop yield (7.8%), soil organic carbon (SOC) pool (12.3% to 36.8%), soil nutrient reserves (1.9% to 15.2%), soil temperature (6.7%), and water contents (5.9%) and improved soil structure when compared with residue removal (P <.05). Negatively, RR may increase soil acidification and significantly increase emissions of greenhouse gases (by 31.7%, 130.9%, and 12.2% for CO2, CH4, and N2O). Nonetheless, the negative effects can be alleviated, and the positive effects can be strengthened by adopting RR in conjunction with appropriate crops, specific farming practices, and avoiding more than 10 years of consecutive use. The results indicated that a higher decomposition of native and newly added organic matters, induced by RR and attendant changes in soil physical properties, could enhance the dynamics of SOC, microbial biomass, soil nutrients, and the final increase in crop yield and greenhouse gases emissions. Thus, the sustainability of RR‐based system could be enhanced by a careful choice and adoption of integrated farming practices. Proper RR management strategies could offer a climate‐smart solution to ensure food security and sustain soil productivity. [ABSTRACT FROM AUTHOR]

In common nutrient management in peach orchards in China, a large amount of nitrogen fertilizer is used. However, low nitrogen absorption and utilization rate results in nitrogen loss and greenhouse gas emissions, which is not favorable for cleaner production in peach orchards. In this experiment, nitrogen leaching, ammonia volatilization, greenhouse gas emissions under bag-controlled release fertilizer (BCRF) were evaluated. In addition, the impact of BCRF on soil nutrient status in peach orchards, peach root system growth, nitrogen absorption and utilization rate, fruit quality, and the potential for using BCRF in major peach-producing areas in China to reduce the amount of nitrogen fertilizer application were also investigated. Results showed that BCRF maintained a stable supply of nutrients to soil, decreased nitrogen leaching, ammonia volatilization and greenhouse gas emissions while nitrogen loss was significantly reduced from peach orchard soil. Also, BCRF reduced the combined global warming potential at 20-, 100-, and 500-years. A 5-year study revealed that application of BCRF promoted the formation of a dense root system in peach trees by the development of fine roots and a more concentrated root distribution. This extended the lifespan of the root system and improved fruit quality. 15N tracer experiments showed that BCRF significantly increased the absorption and utilization rate of nitrogen by peach trees. BCRF reduced the amount of nitrogen fertilizers applied by 65–82% compared to common fertilizer application methods without decreasing peach yield, so it has huge potential for reducing the amount of nitrogen fertilizer used as well as fertilizer input costs in peach production. The results showed that BCRF has huge application potential as a new, environmentally friendly, low-cost, and efficient fertilizer for cleaner production in peach orchards. Image 1048 • Bag-controlled release fertilizer can maintain stable supply of nutrients to soil. • HighlightsHighlightBag-controlled release fertilizer decreases nitrogen leaching, ammonia volatilization from peach orchard soil. • Bag-controlled release fertilizer would reduce greenhouse gas emissions and the combined global warming potential. • Bag-controlled release fertilizer promotes the formation of a dense root system of peach trees. • Bag-controlled release fertilizer has a huge potential for reducing the nitrogen applied amount in peach production. [ABSTRACT FROM AUTHOR]

Mulching, an agricultural management measure widely used in arid and semi-arid regions of China, can effectively improve the hydrothermal environment of farmland and increase crop yield and crop water productivity (WP c). However, previous studies on the effects of mulching on water saving, yield increase and emission reduction of maize have provided inconsistent results. Therefore, a meta-analysis was used in this study to (1) evaluate the effect of mulching types [plastic film (PM), straw (SM) and degradable film (DM)] on maize yield, evapotranspiration, WP c and greenhouse gas emissions; and (2) determine the effects of mulching measures on water saving, yield increase and emission reduction in maize farmland under different climatic conditions. Compared with the no-mulching control, mulching significantly raised maize yield, WP c and carbon dioxide (CO 2) and nitrous oxide (N 2 O) emissions. The PM, SM and DM increased maize yield by 27.31 %, 6.98 % and 16.55 % compared with no-mulching, respectively, and correspondingly WP c by 34.08 %, 11.48 % and 24.20 %. The PM and SM significantly increased CO 2 emissions by 39.91 % and 16.43 %, respectively, and N 2 O emissions by 51.1 % and 30.12 %, but had no significant effect on methane absorption. For maize planting, in areas with altitudes < 500 and > 1000 m, average annual rainfall < 1000 mm, average annual air temperature of 5–15 °C and average annual evaporation < 1500 mm, a combination of PM and ridge–furrow planting can achieve the best effect of increasing production and saving water. In areas with an altitude of 1000–1500 m and average annual evaporation of 1500–2000 mm, the DM had the greatest effect of improving yield (by 16.17 %) and saving water, with a decrease in evapotranspiration of 8.82 % and an increase in WP c of 24.71 %. The local level of mechanization and labor costs should be considered when choosing a maize mulching pattern. • Mulching practice boosted maize yield, WP c and greenhouse gases emission in China. • The combination of PM and ridge-furrow planting is the best way to save water and increase yield in arid and rainless areas. • The water-saving and yield increasing effect of SM is generally inferior to PM and DM. [ABSTRACT FROM AUTHOR]

With the increasing global warming concerns, appropriate agronomic practices for improving crop yields while reducing greenhouse gases (GHGs) emissions are essential for sustainable agricultural production. However, little information is available if these benefits can be achieved simultaneously in arid pastoral agriculture systems with irrigation and nitrogen (N) management. We assumed that the local practiced irrigation (600 mm) and N (300 kg ha−1) applications for spring wheat in the arid regions of Northwest China are excessive, and optimizing irrigation-N rates would improve the resource use efficiency of alfalfa and reduce GHGs emissions. A two-year field study (2015–2016) was conducted to investigate the effects of irrigation regimes (I L , 300 mm; I M , 450 mm; and I H , 600 mm) and N application rates (F 0 , 0; F L , 150; F M , 225; and F H , 300 kg ha−1) on forage yield, resource use efficiency, and GHGs emissions from alfalfa fields. The GHGs emissions during alfalfa growing seasons were assessed by analyzing gas samples using the static chamber-gas chromatography method. High irrigation and N application (I H F H) was associated with elevated GHGs emissions, global warming potential, and greenhouse gas intensity, but lower irrigation water productivity (IWP) and partial factor productivity of N (PFP N). Reducing the irrigation and N rates decreased the GHGs emissions but differently affected alfalfa yield and resource use efficiencies. Among all the treatments, I M F L and I H F L resulted in the highest alfalfa yields, IWP, and PFP N. However, I M F L showed a good trade-off between yield benefits and environmental performance manifested by lower GHGs emissions, GWP, and GHGI. The I M F L reduced the cumulative emissions of nitrous oxide by 67.83% and 67.16%, carbon dioxide by 31.05% and 34.60%, GWP by 61.72% and 70.40%, and GHGI by 74.37% and 79.78%, while increased alfalfa yield by 49.24% and 46.45%, IWP by 99.05% and 94.97%, and PFP N by 198.44% and 192.90% compared to I H F H. Regardless of all the treatments, the alfalfa field acted as a CH 4 sink during both crop-growing seasons. Our results suggest that the application of 450 mm irrigation and 150 kg N ha−1 could be used as an appropriate management strategy for enhancing resource use efficiencies and mitigating GHGs emissions, GHGI, and GWP from alfalfa fields. The findings can provide an opportunity for greenhouse gas mitigation without alfalfa forage yield reduction following the proper irrigation and fertilization regimes in the arid region of northwest China and areas with similar agro-climatic conditions. • Intensive irrigation and fertilization increase GHGs emissions and global warming potential. • Enhancing resource use efficiency with suitable irrigation and N rates mitigate GHGs emissions. • Soil moistures and inorganic N contents are the major factors regulating GHGs emissions. • 450 mm irrigation and 150 kg N ha–1 maintain high alfalfa yields and minimize environmental impacts. [ABSTRACT FROM AUTHOR]

Increased rice production, which benefitted from cropping areas expansion and continuous N applications, resulted in severe increases in greenhouse gases (GHG) emissions from 1983 to 2019 in Heilongjiang Province, China. Therefore, field trials were performed in the high-cold Harbin region, Northeast China, to determine the efficiency of incorporating water regimes with N fertilization in minimizing the impact of rice production on GHG emissions. Two water-saving irrigation strategies, intermittent irrigation (W1) and control irrigation (W2), were used relative to continuous flooding (W0), and we combined them with six fertilized treatments. Our results demonstrated that W1 and W2 significantly decreased seasonal CH 4 emissions by 19.7-30.0% and 11.4-29.9%, enhanced seasonal N 2 O emissions by 77.0-127.0% and 16.2-42.4%, and increased significantly yields by 5.9-12.7% and 0-4.7%, respectively, compared with W0. Although trade-offs occurred between CH 4 and N 2 O emissions, W1 and W2 resulted in significant reductions in global warming potential (GWP). Moreover, low N rates (<120 kg N ha -1 ) performed better in GWP than high N rates. N fertilization and irrigation regimes had remarkable effects on rice yields and GWP. In conclusion, the incorporation of W1 and a N application under 120 kg N ha -1 could simultaneously mitigate GWP while enhancing production in black soils in high-cold Northeast China.