Fertility-Based Nitrogen Management Strategies Combined with Straw Return Enhance Rice Yield and Soil Quality in Albic Soils

Low productivity in albic soils often results in excessive nitrogen input, while straw return further increases nitrogen accumulation through decomposition. To address this issue, a three-year field experiment was conducted in albic soils of high, medium, and low fertility. Two nitrogen management strategies were assessed: nitrogen addition and reduction. Addition treatments included conventional nitrogen application rate alone (N), straw return (8250 kg ha−1) with conventional nitrogen application rate (SN), and straw return with increased nitrogen (SN+). Reduction treatments comprised SN and straw return with 10%, 20%, and 30% reduced nitrogen (SN0.9, SN0.8, and SN0.7). Soil physical properties, nutrient content, and rice yield were evaluated. Results showed that SN0.9 exhibited advantages in high-fertility albic soils, as it increased rice yield and improved some soil quality while reducing the nitrogen input by 10%. However, yield under SN0.9 declined progressively over the three years, indicating limitations of long-term application. SN performed better than both N and SN+ in medium- and low-fertility albic soils, offering better yield and soil quality improvements. However, nitrogen overaccumulation risk under continuous application should not be overlooked. These findings highlight that fertility-based nitrogen adjustment combined with straw return can simultaneously improve rice productivity and soil quality while reducing nitrogen input in albic soils.