Stover return enhances the transformation and sequestration of photosynthetic carbon through regulating soil food web

[Geoengineering News]

https://www.sciencedirect.com/science/article/abs/pii/S0959652625022668?via%3Dihub

Authors: Yijia Tian, Xinchang Kou, Tingting An, Liangjie Sun, Qi Li, Wenju Liang, Xiaoke Zhang 

https://doi.org/10.1016/j.jclepro.2025.146910

Highlights

•Stover return triggered photosynthetic carbon turnover into soil and soil food web.

•Microfauna controlled the trade-off between soil active and stable carbon.

•Crop, soil, and soil food web synergistically promoted the carbon transformation.

Abstract

In agroecosystems, the biological fixation of atmospheric carbon by crops through photosynthesis is one of the most important precursors of soil carbon sequestration. Residue return as a conservational agricultural management practice replenishes soil carbon substrates and triggers soil food web. However, there is still a lack of studies on the priming effect of residue return on photosynthetic carbon transformation and turnover, and then soil carbon sequestration through regulating soil food web, which hinders us from evaluating the efficiency and sustainability of resource utilization. To analyze the priming effect of residue return, stover return (SR) and stover removal (CK) were conducted in the maize field experiment. Then the situ 13C labeling microplot experiment was further carried out to trace crop photosynthetic carbon turnover pathway into soil on the basis of the field experiment. We found the contents of both particulate organic carbon and mineral-associated organic carbon were 30.96 % and 11.39 % higher in SR than in CK respectively, and the significant differences in the soil biota community composition was found between the both treatments in the field. The 13C labeling experiment showed the greater values of 13C from crop, soil (particulate and mineral-associated organic carbon), soil microbes and microfauna in SR than in CK on the 10th labeling day, which indicated photosynthetic carbon turnover into soil and soil food web was enhanced with increasing days. Compared to soil microbes and mesofauna, soil microfauna explained the 60.5 % of soil carbon renewal. Microfauna as an intermediary promoted crop photosynthetic carbon accumulation into the soil. Positive relationships among different soil biotic groups indicated that stover return strengthened the synergistic effects within the soil food web, thereby influencing the trade-off between soil active carbon and stable carbon. In conclusion, the stover return enhanced the incorporation of photosynthetic carbon into soil and the soil carbon sequestration through the synergistic effect of crop-soil-soil food web.

Source: ScienceDirect