Journal of the Indian Society of Soil Science

Availability of P in soil was recorded significantly low with tar, wax and lac coated SSP while it was significantly enhanced under SSP coated with Mussoorie rock phosphate (MRP), gypsum, cowdung, poultry manure, mahua oil, neem oil and gum against uncoated SSP at every growth stage. Phosphorus concentration in plant parts and its uptake by crop of black gram were maximum with MRP coated SSP followed by gypsum coated SSP. A significant increase in P uptake and concentration of P in plant parts was also found with gum, cowdung, poultry manure, mahua oil and neem oil treated SSP but coating of SSP with tar, wax and lac adversely affected these parameters. A considerable improvement in build up of total phosphorus in soil was observed under all treatments except control. Build up of phosphorus in terms of total P was significantly highest when SSP was coated with tar, wax and lac. Overall, the coating of SSP with MRP and gypsum was found more effective with regards to phosphorus availability, its utilization and uptake by black gram while coating of SSP with tar, wax and lac was found ineffective.