Journal Article

Effect of Corn Straw Returning Under Different Irrigation Modes on Soil Organic Carbon and Active Organic Carbon in Semi-Arid Areas

Gu, Yue, Wu, Jinggui, Cheng, Wei, Duo, Xinqu, Ma, Xiaochi

2025

Overview

In the global agricultural production system, maintaining and improving soil quality are core elements for ensuring food security and sustainable agricultural development. As a key indicator of soil quality, the content and dynamic change in soil organic carbon have a profound impact on the physical, chemical and biological properties of soil, and play a decisive role in soil fertility, structural stability, water and fertilizer conservation capacity and microbial activity. However, its decomposition is slow, and a large number of straws returning to the field will impact crop growth; its combination with irrigation is a more reasonable solution, as it can significantly improve the soil environment, increase soil moisture and promote straw decomposition. Therefore, in order to further study the effects of different irrigation methods and straw-returning combinations on soil active-carbon content, an experiment was carried out in long-term arid and semi-arid areas under in-field corn cultivation during 2019–2020. Three irrigation modes were designed—flood irrigation (BI), shallow drip irrigation (SD) and drip irrigation under film (DP)—and straw returning (CS) and no straw returning (CK) were set up, with irrigation applied at critical corn growth stages (internode elongation, heading, bell mouth stage) to support plant growth. The results are as follows: (1) The content of soil organic carbon in different treatments had a gradual upward trend with the advance of growth period; the content of soil organic carbon in DP treatment was significantly higher than that in SD and BI treatment under the same straw returning mode, indicating that drip irrigation under film and straw-returning mode can synergistically improve soil fertility and organic carbon content. (2) Different irrigation methods and straw-returning methods have significant effects on the content of soil active organic carbon components. Different drip irrigation modes can significantly improve the content of soil POC and MBC compared with flood irrigation. The Kos of SD treatment is significantly higher than that of other irrigation treatments, and the CPMI is lower than that of the other two irrigation methods, indicating that the soil organic carbon of SD treatment is more stable. Therefore, under straw-returning conditions, drip irrigation can significantly improve the carbon content of soil components and the management index of soil carbon pool, thus significantly increasing the accumulation of soil organic matter. This study discussed the effects of straw returning on soil organic carbon composition and soil carbon pool index under different irrigation methods to provide theoretical and practical bases for the selection and promotion of straw-returning methods and rational irrigation methods in semi-arid areas.

• Publisher: MDPI AG
• Subject: activated carbon storage / Agricultural production / Agriculture / Carbon content / Carbon sequestration / Corn / Decomposition / Economic indicators / Fertilizers / Food supply / inert carbon storage / Irrigation / irrigation mode / Microorganisms / returning straw to the field / Security management / Soil ecology / Soil fertility / Soils / Water