Different straw lengths and burial modes affect the salt distribution in coastal saline soil and the regulation of salt stress resistance in tomato

Aims

Straw return represents an effective measure for the improvement of saline soil. In order to address the deficiencies of conventional long-strip straw interlayer and straw topsoil mixing, as well as to leverage the regulation of salt stress resistance in plants, this study devised an innovative straw return method that combined powder straw interlayer and topsoil mixing. The objective of this method was to reduce soil salinity, improve soil structure, and promote plant growth.

Methods

A tomato pot experiment was conducted to compare the effects of different straw lengths (S₅₀: 50 mm, S₁₀: 10 mm, S₂: 2 mm) and burial modes (W_i: interlayer, W_m: topsoil mixing, W_im: interlayer and topsoil mixing) on the soil physicochemical properties, tomato root biochemical indexes, fruit yield and dry matter weight of above-ground.

Results

The study found that: (1) Straw burial mode exerted a more pronounced impact than straw length on the salt distribution of soil. (2) The S₅₀W_im, S₁₀W_im, and S₂W_im treatments exhibited more significant differences on the non-uniform distribution of salt, thereby promoting the regulation of tomato roots to salt stress and effectively mitigating its adverse effects. (3) The S₂W_im treatment can significantly improve tomato fruit yield and dry matter weight of above-ground.

Conclusion

It was concluded that the straw return method that combined 2 mm powder straw interlayer and topsoil mixing (S₂W_im) can effectively optimize the salt distribution of soil, promote the regulation of tomato to salt stress, alleviate the adverse effects of salt stress, and ultimately improve tomato fruit yield.