Management of Brackish Water for Crop Production in Two Different Textured Soils

Abstract

| In Pakistan, renewable freshwater resources are decreasing due to unpredictable rainfall changes and farming community is compelled to use underground brackish water. Therefore, a lysimetric study was undertaken to remediate hazardous effects of brackish water on rice-wheat crops through practicable and economical methods in two different textured soils. Treatments were: (A) Types of soils. 1) sandy loam, 2) clay loam, (B) Remedial strategies, 1). canal water, 2) saline-sodic tube well water (continuous), 3) three irrigations of tube well water and two of canal water in a cyclic manner (short cyclic use), 4) tube well water + gypsum @ RSC of water, 5) tube well water+ canal water in 1:1 ratio (conjunctive use). Data showed that the highest biomass and paddy/grain yield were produced by canal water (T1) followed by (T3) where three irrigations of tube well water and two of canal water were used in a short cyclic manner. Whereas, growth and yield of rice and wheat crops were significantly reduced by continuous use of brackish water (T2) and maximum pHs, ECe and SAR were noted in this treatment in both textured soils. Different management practices (use of gypsum and blending) also mitigated the ill effects of saline-sodic water. Therefore, it was concluded that when fresh-water resources are finite and use of saline-sodic water is inevitable, cyclic use of canal and saline-sodic water is a wise and profitable management strategy with marginal effect on crop productivity and proves least detrimental for soil health. Comparison of two different textured soils also revealed that brackish water deteriorated the soil properties of clay loam soil more in comparison to sandy loam soil that highlighted the primary role of soil texture for salinity development and must be recognized while using the brackish water for irrigation purpose.