Abstract

The impact of paper mill effluent irrigation along with soil amendments (FYM, composted coir waste, pressmud and lime + FYM) on the yield, nutrient content and their uptake in rice was studied in an acid and a neutral soil of Thambirabarani river tract. Effluent irrigation resulted in an increase in the Ca and Na contents and a decrease in the K content of rice grain and straw in both the soils. The N content of the grain and straw showed an increase for the effluent irrigation in neutral soils and a decrease in acid soil. A marked reduction in the total N and K uptake as well as the grain and straw yield of rice under the effluent irrigation treatments was recorded in both the soils. Effluent irrigation decreased the Ca uptake of rice in neutral soil and increased the Na uptake in acid soil. The soil amendments had a favourable effecton the P and K uptake of rice in acid soil. The use of 50% diluted clarified effluent was found superior to raw effluent irrigation more particularly in neutral soil. The adverse effect of raw effluent irrigation was more in neutral soil compared to acid soil. Application of composted coir waste improved the grain yield of rice when raw effluent was used for irrigation in neutral soil.

Keywords: Paper mill effluent, Utilisation of effluent, Rice, nutrient content, Nutrients uptake