Wheat-Maize Intercropping With Reduced Tillage and Straw Retention: A Step Towards Enhancing Economic and Environmental Benefits in Arid Areas

Abstract

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.