Effect of Irrigation Water Quality and Soil Compost Treatment on Salinity Management to Improve Soil Health and Plant Yield

Abstract

Increasing soil salinity and degrading irrigation water quality are major challenges for agriculture, resulting in deteriorated soil health and reduced crop yield. This study investigated the effects of irrigation water quality and incorporating compost into soil on minimizing soil salinization and promoting sustainable cropping systems. A greenhouse study was conducted using brackish water (electrical conductivity of 2010±43 µS/cm) and agricultural water (792±12 µS/cm,  a blend of reverse osmosis permeate with brackish water) to irrigate replicate soil columns, simulating an agricultural field with a clay/loam soil profile to evaluate the effects of compost treatment (10% mass in soil) on plant growth, leaching of Na+, Cl-, and NO3-, and soil organic carbon. Compost treatment enhanced soil water retention, maintaining soil moisture above 0.280 m3/m3, reducing NO3- leaching from soil by 16% and 23.5% for agricultural and brackish water irrigation, respectively, increasing plant carbon assimilation by ~30%, and improving plant growth by >50% irrespective of irrigation water quality. The compost-incorporated soil irrigated with brackish water showed the highest plant growth by increasing plant wet weight by 63.6%, dry weight by 50%, root length by 121%, and plant height by 15.8%. Compost treatment reduced soil sodicity using brackish water for irrigation by promoting the leaching of Cl- and Na+ from the soil. Compost treatment provides an environmentally sustainable approach to managing soil salinity, remediating the impact of brackish water irrigation, improving soil organic matter, enhancing the availability of water and nutrients to plants, and increasing plant growth and carbon sequestration potential.

Keywords: agricultural irrigation, salinity management, soil compost treatment, plant biomass, Brackish water, carbon sequestration