Straw return with nitrogen fertilizer promotes rice yield through change in nutrient dynamics within soil aggregates in saline sodic soils

• Published in: Journal of soils and sediments Vol. 24; no. 2; pp. 928 - 945
• Main Authors: Gao, Jiayong, Zhao, Zhexuan, Zhang, Yutong, Ran, Cheng, Geng, Yanqiu, Zhang, Qiang, Du, Juan, Guo, Liying, Shao, Xiwen
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2024; Springer Nature B.V
• Subjects: Aggregates; Biological fertilization; Bulk density; Crop growth; Crop yield; Earth and Environmental Science; Environment; Environmental Physics; Fertility; Fertilization; Fertilizers; Nitrogen; Nutrient content; Nutrient dynamics; Nutrients; Optimization; Organic carbon; Organic phosphorus; Organic soils; Phosphorus; Potassium; Productivity; Regression analysis; Rice; Saline soils; Sec 5 • Soil and Landscape Ecology • Research Article; Sodic soils; Soil; Soil aggregates; Soil improvement; Soil salinity; Soil Science & Conservation; Soil structure; Soils; Straw; Straw retention; Soil organic carbon; Nutrient release; Water-stable aggregate
• ISSN: 1439-0108; 1614-7480
• DOI: 10.1007/s11368-023-03688-4

Purpose Saline sodic soils pose challenges for crop growth due to their high soil salinity, poor structure, and low nutrient content and effectiveness. As a result, there has been increasing interest in using straw return to the field as a means to enhance productivity. However, the impact of straw return and nitrogen fertilization on soil aggregates and nutrient dynamics in saline sodic soils has not been fully understood yet. Methods The present study conducted a 3-year positional experiment to examine the effects of straw return (S 0 : 0, S 1 : 7 t ha −1 ) and nitrogen fertilization (N 0 : 0, N 1 : 150, N 2 : 250, and N 3 : 350 kg ha −1 ) on bulk density (BD), aggregate distribution, nutrient dynamics, and rice yield. Results Straw return to the field promoted the transformation of aggregates into larger ones, resulting in increased aggregate stability. Additionally, it significantly reduced the BD by 8.5 to 10% and increased the soil organic carbon (SOC), nitrogen (N), phosphorus (P), and potassium (K) content of the aggregates. The 0.25–2 mm aggregates were found to be the major contributors to fertility enhancement. There were no significant differences in the structure of the aggregates and the nutrient levels between the N 2 and N 3 treatments. Straw return led to a significant increase in rice yield by 20.90 to 27.57%. However, the differences between the S 1 N 2 and S 1 N 3 treatments were not significant, indicating that S 1 N 2 had better benefits. Regression analysis revealed that the optimum nitrogen application rate tended to decrease with the increase in years of straw return. Conclusion The incorporation of straw and optimal nitrogen (quantity) into saline sodic soils can enhance soil structure and aggregate nutrients, particularly in 0.25–2 mm aggregates. This agronomic measure is viable in improving soil productivity which ultimately increases rice yield.