Microbial C/N metabolic capabilities contribute to the fate of crop residue N in plant-soil-microbe continuum over multiple seasons

• Published in: iScience Vol. 28; no. 5; p. 112499
• Main Authors: Xie, Zhihuang, Li, Yansheng, Yu, Zhenhua, Wang, Guanghua, Liu, Xiaobing, Tang, Caixian, Liu, Junjie, Liu, Judong, Wu, Junjiang, Herbert, Stephen J., Jin, Jian
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 16.05.2025; Elsevier
• Subjects: Agricultural science; Applied microbiology; Microbiology; Soil biology; Soil ecology; Soil science; Agricultural science; Soil biology; Soil science; Microbiology; Applied microbiology; Soil ecology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2025.112499

The mineralization of crop residue-nitrogen (N) is important for sustainable N supply to subsequent crops. However, the microbial mechanisms regarding residue-N mineralization over growth seasons are still unclear. We amended 15N-labelled maize and soybean residues to a Mollisol soil and found that, after three growth seasons, soybean plants utilized 43% and 37% of soybean and maize residue-N, respectively. Approximately 10.5% of soybean and 18.6% of maize residue-N were recovered in the labile N pools in soil. Over time, 82% of soybean residue-N was mineralized compared with 66% for maize residue-N. Greater increases in abundances of microbial functional genes involved in organic C decomposition, N mineralization, N2 fixation, and denitrification were observed in the soybean residue compared to the maize residue treatment. The study implies that soybean residue amendment may lower fertilizer N input more effectively than maize residue, considering the N balance between crop demand and soil supply in farming Mollisols. [Display omitted] •The mineralization of soybean residue-N was greater than maize residue over time•The majority of mineralized residue-N was utilized by subsequent soybean plants•The enriched C and N genes contributed to the strong mineralization of soybean residue•The loss of soybean residue-N from the system was greater than maize over time Soil science; Microbiology; Applied microbiology; Agricultural science; Soil ecology; Soil biology