1. Long-Term Minimum Tillage and Straw Retention Promote Macroaggregate Formation, Carbon and Nitrogen Sequestration under Wheat-Maize Rotation in Northern China
- Author
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Zhijie Ren, Xiaojie Han, Zhidong Han, Wenzhong Tian, Junhong Li, Junjie Lv, Yuanxin Shen, Yingxin Xie, Geng Ma, Gezi Li, Yanan Zhao, and Chenyang Wang
- Subjects
carbon sequestration mechanism ,conservation tillage ,straw mulching ,aggregate-associated C and N ,mineral-associated organic matter ,Agriculture (General) ,S1-972 - Abstract
Conservation tillage is believed to promote soil aggregate stability, carbon (C) and nitrogen (N) sequestration, but the underlying mechanisms remain unclear. In this study, soil samples from an 18-year experiment including conventional tillage with straw removal (CT), deep scarification with straw mulching (DS), and no-tillage with straw mulching (NT) were used to obtain different fractions based on a comprehensive wet-sieving method of aggregate and particle size. The results showed that NT and DS increased soil organic carbon (SOC) and N by 9.3–16.4% and 10.8–25.8%, respectively, in addition to increasing the weight proportion of macroaggregates and the contribution of macroaggregate-associated C and N to total SOC and N. The C change in the total POM accounted for 77.4% and 79.9% of the total SOC increase by NT and DS, while the MAOM only accounted for 29.2% and 25.2%, respectively. Meanwhile, microaggregates-within-macroaggregates accounted for 96.9% and 90.5% of the SOC increase by NT and DS, respectively. The total SOC and N were positively correlated with the C and N of the macroaggregates and subfractions. In conclusion, the formation of macroaggregates drives soil C and N sequestration under conservation tillage, and POM and mM were important functional pools in this process.
- Published
- 2024
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