Sustainable use of brackish water for cotton wheat rotation
Ghulam Qadir, Khalil Ahmed*, Amar Iqbal Saqib, Muhammad Ilyas, Muhammad Qaisar Nawaz,
Muhammad Sarfraz, Zaheen Manzoor
Soil Salinity Research Institute Pindi Bhattian, Pakistan
Abstract
The challenge of 21st century is to meet the food, fuel and fiber requirement of an increasing world population on a sustainable basis. Moreover, drought conditions, increasing demands of freshwater for agriculture and industrial sector has forced the farming community to pump more and more groundwater which is of marginal quality. This marginal quality water can be successfully used to increase agricultural productivity by preventing soil degradation if suitable management approaches are coupled with proper amendments. Therefore, a field study was conducted to manage the deleterious effects of brackish water for the sustainable production of cotton and wheat crops. The treatments tested were; T1: Control [Brackish Water (BW)], T2: BW + Gypsum application @ 100% on the basis of RSC of water, T3: BW + H2SO4 @ 50% application on the basis of RSC of water, T4: BW + Poultry manure @ 10 t. ha-1, T5: BW+ Press mud @ 10 t. ha-1. A non-saline field (ECe = 2.34 dS m-1, pHs = 8.15 and SAR = 8.58) was selected, leveled, and prepared. The experimental design was RCBD with four repeats. Cotton-wheat cropping system was followed. Brackish water was used {EC = 1.17 dS m-1, SAR = 6.75 and RSC = 5.30 me L-1} for irrigation. Data regarding different physiological and yield parameters were recorded at maturity. Pooled data analysis of three years showed that continuous use of brackish water significantly reduces the yield of cotton and wheat crops. However, the negative effects of brackish water were counteracted by all applied amendments while chemical amendments were more efficient in ameliorating the detrimental effects of brackish water. Maximum seed cotton yield (2.50 t. ha-1) for cotton and grain yield (4.32 t. ha-1) for wheat was recorded in T2: BW + Gypsum application @ 100% on the basis of RSC of water followed by T3: BW + H2SO4 @ 50% application on the basis of RSC of water. Soil analysis data showed that ECe, pHs and SAR were considerably improved with all the applied amendments as compared to control.
