Xie Zhihuang, Li Yansheng, Yu Zhenhua, Wang Guanghua, Liu Xiaobing, Tang Caixian, Liu Junjie, Liu Judong, Wu Junjiang, Herbert Stephen J, Jin Jian
Engineering Research Center of Soil Remediation of Fujian Province University, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China.
iScience. 2025 Apr 22;28(5):112499. doi: 10.1016/j.isci.2025.112499. eCollection 2025 May 16.
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 N-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, N 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.
作物残茬氮（N）的矿化对于后续作物的可持续氮供应至关重要。然而，关于生长季节中残茬氮矿化的微生物机制仍不清楚。我们将氮标记的玉米和大豆残茬施用于一种软土，发现经过三个生长季节后，大豆植株分别利用了大豆和玉米残茬氮的43%和37%。土壤中不稳定氮库中回收了约10.5%的大豆残茬氮和18.6%的玉米残茬氮。随着时间的推移，82%的大豆残茬氮被矿化，而玉米残茬氮的这一比例为66%。与玉米残茬处理相比，在大豆残茬处理中观察到参与有机碳分解、氮矿化、固氮和反硝化的微生物功能基因丰度有更大增加。该研究表明，考虑到软土耕作中作物需求与土壤供应之间的氮平衡，施用大豆残茬可能比施用玉米残茬更有效地降低化肥氮投入。
