Impact of distillery effluent application along with inorganic fertilizers on dry matter yield and mineral composition of rice

Abstract

A greenhouse experiment was conducted to study the impact of premethanation (PREME) and postmethanation (POME) distillery effluent applied as pre-sowing irrigation (PSI) along with graded levels of inorganic fertilizers on the grain and straw yield and nutrient content of a rice crop (var. PR 116). Maximum grain yield (29.4 g pot−1) was recorded with the application of 100% recommended NPK along with one pre-sowing irrigation (PSI) through POME and the lowest yield (7.4 g pot−1) was obtained with 2 PSI applied through PREME without any inorganic fertilizers. The application of POME equivalent to 1 PSI was more effective in increasing the grain and straw yield of rice than no POME application or POME application equivalent to 2 PSI. A significant decrease in yield occurred with the application of 2 PSI of either effluent, and beyond 2 PSI the rice seedlings did not grow.In comparison to POME, the application of PREME increased the content of K (5%), Cu (10%), Fe (17%) and Mo (21%), but decreased that of P (12%), S (5%) and Mg (11%) in rice grain. In rice straw an increase was only observed in K (9%) and Mo (14%), while the contents of other nutrients (P, S, Zn, Cu, Mn) decreased by 8 to 21%. An increase in the level of effluent from 0 to 2 PSI significantly increased the content of N (by 21%), K (11%), S (10%), Zn (9%), Cu (21%) and Mo (8%), but decreased that of P (16%) and Mg (19%) in rice grain. In the case of rice straw, an increase in K (28%), S (32%), Cu (65%) and Mo (45%) content was recorded. Effluent application, inorganic fertilizers and their interactions had a significant effect on both the grain and straw yields and on the nutrient concentration in the plants.