Influence of microbial culture in combination with micronutrient in improving the groundnut productivity under alluvial soil of India

A field experiment was carried out to study the effect of cobalt, Rhizobium and phosphobacterium inoculations on growth, yield and nutrient uptake of summer groundnut in an alluvial soil at three levels of cobalt viz., zero, 0.21 kg and 0.42 kg ha-1 with four levels of inoculations viz., uninoculation, inoculation with Rhizobium, inoculation with phosphobacterium and inoculation with both Rhizobium and phosphobacterium. Results indicated that combined application of Rhizobium and phosphobacterium inoculation promoted higher dry matter production, pod yield, oil content and nutrient uptake as compared to application of either of the inoculations. Cobalt @ 0.21 kg ha-1 proved to be better to other doses of cobalt. The percent increase in pod yield of different treatment combinations over untreated control varied from, 2.4% with no inoculation + cobalt @ 0.42 kg ha-1 to 35.6% with Rhizobium + phosphobacterium + cobalt @ 0.21 kg ha-1. The uptake of N, P and K by groundnut was significantly higher in the treatments receiving both inoculation and cobalt at 0.21 kg ha-1 than sole application of either inoculation or cobalt.