Possibilities of using brackish water for crop production

Abstract

Three studies were carried out in different types of soils at different sites with different treatments. In a first study with silt loam soil three treatments viz. pure tubewell water (T1), tubewell water passing through gypsum stone beds (T2) and tubewell water with gypsum in soil on water quality basis of 100% GR (T3) were tried. The tubewell water had 1.245 EC (dS m^-’) and 14.37 SAR. The soil EC,, was increased insignificantly in all the treatments whereas the SAR was significantly increased in treatment 1. Comparable yield with gypsum application in soil was obtained by gypsum stones placed in watercourse. Gypsum stones seems economical source of calcium for amending sodic water for irrigation.

In a second study laid down in sandy clay loam soil ridge planting (T1), double row bed planting (T2) and flat basin planting (T3) were tried using water having 3.0-3.9, 3.2-4.3 and 0.0EC (dS m^-’) SAR and RSC (me 1^-1) respectively. Cotton-maize crop rotation was followed with two varieties each. More salts were accumulated at the top of ridge/bed and middle of bed and minimum SAR of soil was observed at the seed site. Ridge and bed planting proved better for increasing the seed cotton yield.

In the 3rd study, a slightly salt affected clay loam soil was used and treatments were: T1. Good quality water only, T2. Alternate irrigations with good and brackish water, and T3. All irrigations with brackish water. The salinity, SAR and RSC of brackish water ranged between 3.20-4.64 (dS m^-’),17.9-23.7 and 3.2-5.0 (me l^-’) respectively. Initially the EC, and SAR decreased in all the treatments but increasing trend, especially in SAR, was observed later on in treatment 3. Wheat grain yield was not significantly affected but sorghum (fodder) yield was affected significantly. The results obtained suggest that brackish water with proper management can be utilized for irrigation without affecting much crop yield and soil properties.