No tillage and previous residual plastic mulching with reduced water and nitrogen supply reduces soil carbon emission and enhances productivity of following wheat in arid irrigation areas

Abstract

Abstract No tillage, optimal nitrogen and irrigation supply levels, and crop rotation are promising strategies for reducing soil carbon emission, and plastic mulching is an important measure to improve crop productivity in arid regions. However, the effect of no tillage and plastic mulching combined with optimum management of water and nitrogen on soil carbon emission has not been tested. A field experiment was carried out in 2016–2018, to evaluate how no tillage, reduced the levels of irrigation and nitrogen affect crop yield, water use, and soil carbon emission of following spring wheat after plastic-mulched maize. A sustainability evaluation index was analyzed via integrating key parameters related to yield performance, water use, and soil carbon emission characteristics. Our results show that no tillage with previous residual plastic mulching, reduced irrigation, and reduced nitrogen application increased yield and water use efficiency of following wheat, but decreased soil carbon emission. From the 3-year average, no tillage and previous residual plastic mulching combined with the reduction of 20 % in both irrigation and nitrogen levels (i.e., the integrated system), increased grain and energy yields of following wheat by 13.7 and 7.8 %, respectively, compared to conventional tillage with conventional high levels of irrigation and nitrogen (i.e., the control). Also, the integrated system improved grain and energy yields for water use efficiency by 7.2 and 4.0 %, respectively. The soil carbon emission with the integrated system was 31.7 % lower than that with the control treatment, and the integrated system reduced soil carbon emission for water use efficiency by 33.8 % compared to the control treatment. However, the integrated system had 65.1 % greater carbon emission efficiency than the control treatment. The integrated system had the highest sustainability index among all treatments. Therefore, no tillage with previous residual plastic mulching from the previous maize combined with a 20 % reduction in both irrigation and nitrogen levels is an optimal strategy for sustainable and effective production of wheat in arid Oasis irrigation regions.