Intercropping regulates plant- and microbe-derived carbon accumulation by influencing soil physicochemical and microbial physiological properties
Zhu, Qirui, Ziyu Yang, Yuping Zhang, Yizhe Wang, Jiangchi Fei, Xiangmin Rong, Jianwei Peng, Xiaomeng Wei and Gongwen Luo
Agriculture Ecosystems & Environment
https://doi.org/10.1016/j.agee.2023.108880
ABSTRACT
Intercropping can increase soil carbon (C) sequestration and utilization by planting a variety of plants on a same land. However, the main plant and microbial -driven pathways leading to the increased C sequestration in intercropping soils are rarely studied. Therefore, it is important to reveal the distinct contributions of plant- and microbe -derived C to soil organic C (SOC) for understanding the regulation of intercropping in global C storage. Herein, two widely accepted sets of bio-markers, namely, amino sugars and lignin phenols, were employed to compare the distribution of plant- and microbe -derived C as well as their contributions to SOC in maize monoculture and intercropping systems, based on a field experiment established in 2013; meanwhile, the associations of soil physicochemical properties and microbial physiological traits with plant- and microbe -derived residues were disclosed via correlation and model analysis. Compared with the monoculture, maize intercropping significantly increased soil amino sugar and microbial necromass C contents as well as their contributions to SOC in maize mature stage; maize inter -planted with gingelly or soybean significantly increased these variables in the elongation stage; meanwhile, maize inter -planted with gingelly significantly increased soil lignin phenol content and its contribution to SOC in the mature stage. In all treatments and growth stages, microbial necromass C contributed more to SOC than lignin phenols, and fungal necromass C contributed more to SOC than bacterial necromass. The contribution of microbial necromass C to SOC was mainly influenced by amino sugar content, microbial C use efficiency, dissolved organic C content, and microbial biomass C content. The contribution of plant -derived C to SOC was mainly influenced by lignin phenol content, pH, and NH4+-N content. These results demonstrate the distinct regulations of maize intercropping on plant- and microbe -derived C to soil C pool by influencing soil physicochemical properties and microbial physiological traits, and meanwhile, highlight the potential of intercropping in global C storage.