Effect of Waste Water Irrigation on Soil Properties under Different Land Use Systems

摘要

Soil properties under five land use systems viz. soybean-gram, sugarcane-paddy, paddy-wheat, vegetables and agri-horticulture, irrigated with waste water from Nag river for past 20 years were compared with unirrigated soils (control) under pigeonpea system. The soils were characterized and analyzed for morphological, physical and chemical properties, available micronutrients and heavy metals. The composition of waste water used for irrigation was also analysed. All the soils were very deep, clayey (with high moisture holding capacity), calcareous and alkaline (pH 7.9-8.5). The morphological properties of soils - colour, structure and consistence and physical properties - texture and bulk density were not altered by irrigation with waste water underdifferent land use systems compared to unirrigated control. Irrigation using waste water improved the availability of Ca, Mg, K, Zn, Cu, Mn and Fe under all the land use systems besides improving the soil organic carbon content in soybean-gram, vegetables and sugarcane-paddy systems. Continuous irrigation using waste water had an adverse effect on EC, ESP, soluble cation (Na/K and Na/Mg) ratios and heavy metal (Pb, Cd, Co and Ni) content.