Effects of depth of straw returning on maize yield potential and greenhouse gas emissions

Junqiang Wang; Yehui Han; Chao Zhou; Ting Xu; Zhongcheng Qu; Bo Ma; Ming Yuan; Lianxia Wang; Yang Liu; Qingchao Li; Xinying Ding; Chunrong Qian; Baoxin Ma

doi:10.3389/fpls.2024.1344647

Effects of depth of straw returning on maize yield potential and greenhouse gas emissions

Front Plant Sci. 2024 Feb 21:15:1344647. doi: 10.3389/fpls.2024.1344647. eCollection 2024.

Authors

Junqiang Wang^#¹, Yehui Han^#¹, Chao Zhou^#¹, Ting Xu¹, Zhongcheng Qu¹, Bo Ma¹, Ming Yuan¹, Lianxia Wang¹, Yang Liu¹, Qingchao Li¹, Xinying Ding², Chunrong Qian³, Baoxin Ma¹

Affiliations

¹ Heilongjiang Academy of Agricultural Sciences, Qiqihar, China.
² Animal Husbandry and Veterinary Branch of Heilongjiang Academy of Agricultural Sciences, Qiqihar, China.
³ Institute of Tillage and Cultivation, Heilongjiang Academy of Agricultural Sciences, Harbin, China.

^# Contributed equally.

Abstract

Appropriate straw incorporation has ample agronomic and environmental benefits, but most studies are limited to straw mulching or application on the soil surface. To determine the effect of depth of straw incorporation on the crop yield, soil organic carbon (SOC), total nitrogen (TN) and greenhouse gas emission, a total of 4 treatments were set up in this study, which comprised no straw returning (CK), straw returning at 15 cm (S15), straw returning at 25 cm (S25) and straw returning at 40 cm (S40). The results showed that straw incorporation significantly increased SOC, TN and C:N ratio. Compared with CK treatments, substantial increases in the grain yield (by 4.17~5.49% for S15 and 6.64~10.06% for S25) were observed under S15 and S25 treatments. S15 and S25 could significantly improve the carbon and nitrogen status of the 0-40 cm soil layer, thereby increased maize yield. The results showed that the maize yield was closely related to the soil carbon and nitrogen index of the 0-40 cm soil layer. In order to further evaluate the environmental benefits of straw returning, this study measured the global warming potential (GWP) and greenhouse gas emission intensity (GHGI). Compared with CK treatments, the GWP of S15, S25 and S40 treatments was increased by 9.35~20.37%, 4.27~7.67% and 0.72~6.14%, respectively, among which the S15 treatment contributed the most to the GWP of farmland. GHGI is an evaluation index of low-carbon agriculture at this stage, which takes into account both crop yield and global warming potential. In this study, GHGI showed a different trend from GWP. Compared with CK treatments, the S25 treatments had no significant difference in 2020, and decreased significantly in 2021 and 2022. This is due to the combined effect of maize yield and cumulative greenhouse gas emissions, indicating that the appropriate straw returning method can not only reduce the intensity of greenhouse gas emissions but also improve soil productivity and enhance the carbon sequestration effect of farmland soil, which is an ideal soil improvement and fertilization measure.

Keywords: greenhouse gases; maize; soil organic carbon; straw returning; yield potential.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by grants from the National Maize Industry Technology system-Qiqihar integrated test station (CARS-02-46), Heilongjiang agricultural science and Technology Innovation Leap Engineering Agricultural Science and Technology Foundation Innovation Youqing Project (CX22YQ15), Heilongjiang provincial research institutes scientific research business expense project (CZKYF2023-1-C013).