Comparative Efficacy of Straw Return Strategies in Ameliorating Coastal Saline‐Alkali Soils in Jiangsu Province, China

As an important reserve of arable land resources, the saline‐alkali soil in the coastal economic zone of Jiangsu Province urgently needs sustainable improvement that balances agricultural productivity and ecological safety. The current traditional straw return practices face a key bottleneck in that they are difficult to coordinate salt regulation and fertility improvement, which seriously restricts regional food security. To date, it remains unclear how different straw types and incorporation methods comparably ameliorate coastal saline‐alkali soils, particularly, their underlying mechanisms. This study presents a systematic assessment of straw return as a sustainable remediation approach for coastal degraded soils, comparing three straw types (wheat, corn, rice) across four incorporation methods (surface mulch, rotary tillage, deep plowing, and control). Straw return alleviates coastal saline‐alkali soil degradation through three interconnected mechanisms: (1) Physical restructuring via straw‐derived organic matter binding soil particles, reducing bulk density (16.7%–20.9%) and enhancing porosity (20.8%) through macroaggregate formation (MWD increase by 27%–35%); PCA revealed rice straw deep plowing (RS‐F3) as the optimal strategy (composite score: 1.12), uniquely synchronizing salt leaching (45% EC reduction) with topsoil organic matter accumulation by vertically redistributing salts while improving aggregate stability. These mechanistic insights enable precision soil management: RS‐F3 is prioritized for salt‐dominated coastal soils, whereas corn straw rotary tillage (CS‐F2) better suits fertility‐deficient areas.