Amelioration of takyric solonetz using drip irrigation with soil‐water‐redistribution medium*

Abstract

AbstractTakyric solonetz is a highly saline‐sodic soil with poor soil structure and a saturated hydraulic conductivity close to zero. Drip irrigation, soil‐water‐redistribution medium (RM), ridge planting and film mulching have been successfully used to ameliorate such soils. Here, we compared soil moisture and cation distribution during the amelioration with planting years of 1, 3, 4, 5 and 6. A suitable root zone with low electrical conductivity, pH and sodium absorption ratio was quickly and continuously formed in the arid area. An irrigation regime with a decreasing soil matric potential threshold of −5 to −20 kPa in improving years 1–4 and stabilized at −20 kPa was feasible. The wetting front kept moving downward with time, and the dry soil layer in the middle of the profile gradually disappeared after 4 years. In the initial 4 years, the Na+ in the root zone leached mainly to the top layer of ridge slope and furrow. And then the Na+ leached downward. The spatial distribution of soil water and Na+ indicated that soil permeability improved with time, and significant changes occurred after the fifth year.