Salt leaching of heavy coastal saline silty soil by controlling the soil matric potential

Abstract

Techniques of drip irrigation are broadly applied for the reclamation of saline-alkali lands, during which effective management of water use to accelerate salt leaching is essential for crop production. In 2017, a field experiment with five treatments of soil matric potential (SMP) levels of −5, −10, −15, −20, and −25 kPa was conducted in heavy saline silty soil land in Bohai Bay, China to study the effects of drip irrigation on salt leaching. The results showed that salt leaching was enhanced with increasing SMP, particularly under an SMP of −5 kPa within a 30 cm soil profile depth and 15 cm distance from the dripper, and the average electrical conductivity of saturated paste extracts (ECe) decreased from 13.8 to 1.52 dS/m. Water consumption increased with increasing SMP, but the yield of oil sunflower did not differ significantly between SMPs of –5 and –10 kPa. These findings indicated that a relatively high crop yield of oil sunflower and effective salt leaching can be achieved if the SMP can be controlled at –10 kPa in heavy saline silty soil.