Comprehensive Analysis and Evaluation of the Reclamation Effect of Saline‐Alkali Soil by Straw Return Methods

ABSTRACT

To systematically evaluate the reclamation effect of different straw return methods on saline‐alkali soils and to identify the optimal approach, this study conducted a comprehensive assessment based on tomato pot‐culture experiments. A total of 12 indicators spanning three dimensions—desalination efficiency, agronomic performance and economic viability—were selected, and principal component analysis (PCA) was employed to evaluate the integrated performance of different straw types (long‐strip, T _l ; short‐strip, T _s ; and powdered, T _p ) and burial schemes (interlayer, B _i ; mixed, B _m ; combined interlayer‐mixed, B _c ). The results indicated that: (1) Straw burial scheme exerted a significantly greater influence on saline‐alkali soil reclamation than did straw type. The establishment of a straw interlayer ( B _i and B _c ) effectively reduced upper soil salinity, enhanced vertical non‐uniform salt distribution, increased tomato fruit yield, dry matter mass, average fruit weight and vitamin C content, while decreasing fruit blossom‐end rot incidence and substantially improving net economic income. PCA composite scores confirmed that the B _i and B _c treatments (with a straw interlayer) scored markedly higher than CK and B _m treatments (non‐interlayer). (2) Powdered straw ( T _p ) treatment further enhanced upper soil desalination, promoted tomato growth and dry matter accumulation, and significantly increased net economic income, with PCA composite scores substantially higher than those of long‐strip straw ( T _l ) treatment. (3) The T _s B _c and T _p B _c treatments achieved the highest PCA composite scores, maximizing the integrated benefits of desalination, yield enhancement and economic income, and thus represented the optimal practices for saline‐alkali soil reclamation. In summary, the combined interlayer‐mixed burial scheme, when applied with short‐strip or powdered straw, synergistically enhanced soil desalination, promoted crop yield and increased economic returns, demonstrating considerable potential for extension and application.