2026/07/08 by Shuai Xie, Jing Fu, Bo Wang +5 · 1 voice
Agricultural and Biological Sciences · #Agronomic Practices and Intercropping Systems #Soil Carbon and Nitrogen Dynamics #Soil Management and Crop Yield
paper · doi:10.1071/sr25193
openalex publication_date 2026/07/08 · openalex created_date 2026/07/10 · openalex updated_date 2026/07/28
Context To investigate the influence of straw return on the stability and carbon (C) and nitrogen (N) dynamics of water-stable aggregates in Black Soils. Aims This study aimed to elucidate the link between aggregates’ organic C stock and the input of exogenous organic matter, thereby revealing the mechanisms of C sequestration enhancement within soil aggregates. Methods A field micro-plot experiment was conducted at the Research and Teaching Base of Jilin Agricultural University, using a randomized block design with three replicates and four treatments: no-till and no straw return (CK), half the standard amount of straw return (4500 kg ha−1, H), full standard amount (9000 kg ha−1, F), and double the standard amount (18,000 kg ha−1, D). Additionally, 15N-labeled urea was applied. Soil samples were collected after one growing season. We assessed the effects of straw return on the size distribution, stability, and C and N concentrations of water-stable aggregates, and analyzed the relationships between aggregate stability indices and nutrient content. Key results The straw return significantly improved soil structure and aggregate stability, concurrently enhancing C and N sequestration within aggregates. Compared to CK, straw return increased the proportion of macro-aggregates (>0.25 mm), mean weight diameter, geometric mean diameter, and the aggregate stability index by 10.00–108.34%, 17.19–202.17%, 14.29–144.44%, and 1.57–10.81%, respectively. Furthermore, organic C concentration and storage, total N concentration, and 15N enrichment in water-stable aggregates were elevated by 0.95–104.55%, 31.54–196.36%, 0.64–202.17%, and 9.38–240.00%, respectively. Conclusions Aggregate stability and nutrient content were positively correlated with straw return rates. The 2–0.25 and 0.25–0.053 mm aggregate fractions were identified as the primary reservoirs of organic C. Implications These findings underscore that straw return is a critical management practice for enhancing soil structure and quality in Black Soils. This study provides a theoretical foundation and technical guidance for utilizing crop residues as organic amendments to improve soil health and increase Csequestration potential in Black Soils.