Combined Effect of Enriched Compost and Microbial Inoculants on Soil Nutrients and Phosphorus Uptake by Rice

Abstract

Preparation of compost enriched with rock phosphate may be considered as a suitable option for utilizing the reserves of low-grade rock phosphate for enhancing the phosphorus use efficiency of crops. This research was carried out to study the effect of combined inoculation of mycorrhiza and selected rhizobacteria on soil nutrients and P uptake by rice. The experiment was conducted in Randomized Block Design with 10 treatments having three replications. The treatments included a control and a complete recommended fertilizer dose along with different combinations of rock phosphate enriched compost, mycorrhiza and rhizobacterial isolates at a lower P dose. Results from laboratory analysis of experimental soil and plant samples suggest that the treatment with rock-phosphate enriched compost @ 100% of the phosphorus dose along with phosphorus solubilizing bacteria and mycorrhiza proved to be the most effective treatment for maintaining a higher nutrient status in soils. On the other hand, rock-phosphate enriched compost @ 50% of the phosphorus dose amended with 50% of the recommended phosphorus from chemical fertilizers along with co-inoculation of phosphorus solubilizing bacteria and mycorrhiza resulted in a higher P uptake by rice. Co-inoculation of microbial inoculants in presence of organic matter can be considered as possible strategies towards improving nutrient status in soils as well as P nutrition to plants for a sustainable soil health.