Impact of Straw Return Rate, Nitrogen Rates and Split Nitrogen Management on Winter Wheat Performance and soil fertility

Optimizing straw and nitrogen (N) management is critical for sustainable crops production, but their interactive effects on yield, soil fertility, and plant traits remain understudied. this 2-year (2023–2024, 2024–2025) randomized block design field experiment with three factors, rice straw return [0%RST,50%RST, 100%RST], nitrogen rate [0 (ck), 180 (n), 220 (h) kg N ha⁻¹], and splitting regimen [1:0:0(n1/h1),7:3:0(n2/h2), 1:1:1 (n3/h3)], were examined. Grain yield (GY) and its components, soil fertility, partitioning of plant nitrogen (N), dry matter (DM) accumulation and partitioning, and photosynthetic traits (SPAD, LAI) were measured in the experiment.Straw return, N rate, N splits, and their interactions had significant impact over all the measured traits (p < 0.05). The 50%RST + h₃ treatment achieved highest, 7.64 ± 0.08 t ha⁻¹(2023–2024) and 9.61 ± 0.24 t ha⁻¹(2024–2025)—grain yields ca. 24.3–35.5% greater than 100%RST or 0%RST on the same h₃ regime. This was also supported by improved yield components (spike no., grains per spike), dry matter accumulation, and photosynthesis capacity.Conversely, 100% straw returning had the best impact on soil fertility for instance ,the 100%RST + h₃ treatment was optimal, producing the highest Soil SN (0.45% and 0.78% at flowering) and Soil SAN (222 and 290 mg·kg⁻¹ at maturity) in the respective seasons—values 28.3 to 48.7% higher than other straw treatments under h₃. Plant N partitioning showed that 50%RST favored N uptake at flowering, while 100%RST enhanced grain N content at maturity. Correlation analysis revealed that GY was very significantly and positively correlated with SPAD (r = 0.90), grains per spike (r = 0.87), and maturity dry matter (r = 0.88).These results suggest a significant trade-off: 50%RST + h₃ maximizes current productivity, and 100%RST + h₃ enhances long-term soil nitrogen pools. This article outlines a definite recipe for the custom fitting of straw and N management (220 kg N ha⁻¹ in three splits) to specific winter wheat production goals, an avenue towards the attainment of both high yield and enduring soil health.