Ameliorating Salt Accumulation and Enhancing Tomato Growth by Shallow-burying a Crop Straw Layer in Coastal Saline Soil

Abstract

【Objective】 Salt accumulation in the proximity of soil surface and poor soil structure are a problem facing agricultural production in coastal regions. The objective of this paper is to explore the potential of using a shallow-buried straw layer to reduce solute ascent to ameliorate salt stresses to crops. 【Method】 The experiment was conducted in pots with tomato used as the model plant. The straw was buried at the depth of 17cm, with the ratio of salt content in the soil overlying and underlying the straw layer being 1∶1, 2∶4, 1∶5, or 3∶3. In each treatment, we measured the variation in soil water and salt, as well as growth and physiological changes of the tomato. 【Result】 Compared to the control (without straw layer), the shallow-buried straw layer significantly reduced soil water loss by 5.7% to 15.0%, and salt content in the upper soil layer by 9.6% to 24.5%, depending on the initial soil salt content and distribution; it also increased the number of roots in the upper soil layer and root mass density, root length density and root surface area by 31.7% to 40.0%, 20.6% to 35.1%, and 26.3% to 26.6%, respectively. It was found that the straw treatment enhanced dry matter accumulation in the above-ground part by 3.3% to 28.8%, increased tomato yield by 12.1% to 80.7%, and improved irrigation water utilization efficiency by 19.1% to 62.5%, compared to the control. 【Conclusion】 Our results show that shallow-burying a straw layer at the depth of 17 cm can effectively slow down soil salt migration, alleviate salt stress to the tomato, and promote tomato growth and yield. It has a potential application for other crops grown in salinized coastal soils.

Keywords

• tomato
• straw interlayer
• water and salt migration
• salt stress
• compensation effect