Straw and residual film management enhances crop yield and weakens CO2 emissions in wheat-maize intercropping system

Zhiwen Gou; Wen Yin; Qiang Chai

doi:10.1038/s41598-021-93497-x

Straw and residual film management enhances crop yield and weakens CO₂ emissions in wheat-maize intercropping system

Sci Rep. 2021 Jul 7;11(1):14077. doi: 10.1038/s41598-021-93497-x.

Authors

Zhiwen Gou^{1

2}, Wen Yin^{1

2}, Qiang Chai^{3

4}

Affiliations

¹ College of Agronomy, Gansu Agricultural University, Lanzhou, 730070, China.
² Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou, 730070, China.
³ College of Agronomy, Gansu Agricultural University, Lanzhou, 730070, China. chaiq@gsau.edu.cn.
⁴ Gansu Provincial Key Laboratory of Aridland Crop Science, Lanzhou, 730070, China. chaiq@gsau.edu.cn.

Abstract

Higher CO₂ emissions and lower crop productivity are becoming thorny problems and restricted sustainable development of agriculture in arid inland areas. Intercropping has been shown to enhance crop productivity. However, Intercropping generally requires more input that led to an increase in CO₂ emissions. It is unknown whether designing tillage and film mulching in reduction could decrease soil CO₂ emissions in intercropping. Therefore, we integrated no tillage combined with residual film mulching and straw returning into wheat-maize intercropping. The maximal soil CO₂ fluxes (F_s) with intercropping was decreased by 12-21% compared to sole maize. Residual film mulching combined with straw returning (NTSMI) significantly reduced average F_s during the entire period of crop growth by 14-15%, compared with the conventional tillage (CTI). Soil CO₂ emissions (CE) with intercropping was 18-20% less than that with sole maize and the NTSMI reduced CE by 12-16% compared to the CTI. The NTSMI boosted total grain yields (GY) by 14-17%, compared with the CTI. Wheat-maize intercropping significantly enhanced soil CO₂ emission efficiency (CEE) by 33-41% in comparison to sole maize, and CEE with NTSMI was increased by 29-40% than that of CTI. A quadratic function for aboveground biomass (BA) combined with two linear functions for soil temperature (T_s) and soil water-filled pore space (WFPS) was suitable for the monitored results. A multiple regression model composed of the above three factors can explain 73-91% of the F_s variation. Crop biomass accumulation at the time of maximal F_s was less with intercropping compared with sole maize. The structural equation indicated that the BA synergistic effect on CEE through combining negative effects on CE and positive effects on GY in intercropping. In conclusion, no tillage with straw returning and residual film mulching in wheat-maize intercropping was confirmed to be an optimum management practice to reducing soil CO₂ emissions and enhancing soil CO₂ emission efficiency in arid inland agroecosystem.

Publication types

Research Support, Non-U.S. Gov't