Sepehya S.,Forages and Grassland Management CSK |
Subehia S.K.,Forages and Grassland Management CSK |
Negi S.C.,Forages and Grassland Management CSK |
Rana S.S.,Forages and Grassland Management CSK |
Sharma S.K.,Forages and Grassland Management CSK
Research on Crops | Year: 2012
Effect of long-term addition of chemical fertilizers alone or in conjunction with organics was studied on different forms of potassium in soil and their relationship with rice yield and K uptake. Continuous addition of chemical fertilizers along with different organics improved all the potassium fractions in soil over control. Integrated use of chemical fertilizers and different organics viz., farm yard manure (FYM), wheat cut straw (WCS) and Sesbania aculeate as green manure (GM) sustained higher yields of rice in comparison to inorganic fertilizers alone. Application of 50% NPK through chemical fertilizers+50% N through organics in kharif followed by 100% NPK through chemical fertilizers in rabi produced highest (43.37 q/ha) rice yield. Accordingly, potassium uptake was also higher under this treatment. A significant positive correlation amongst the different forms of potassium in soil suggested the existence of dynamic equilibrium amongst themselves. Grain and straw yield of rice was also positively and significantly correlated with all the fractions of potassium in soil. The degree of correlation in respect of rice yield was highest with exchangeable K (0.535). Uptake of potassium in grain and straw and total K uptake was also positively and significantly correlated with all the fractions of potassium. A highest correlation of total K uptake (0.622) was observed with water soluble K.