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.
