Effect of Phytase Enzyme and Phosphatic Fertilizers on Available Phosphorus in an Alfisol

An experiment involving sixteen treatments with four levels of phytase (0, 240, 480, 720 IU) and four levels of phosphorus (0, 25, 50, 100 kg ha-1) was carried out during kharif 2017 to assess the availability of phosphorus at 0, 15, 30, 45, 60 and 90 days (DAI) after incubation. There was an increase in soil available phosphorus up to 45th days of incubation either with the application of phytase or P and it reduced after 60 days of incubation. Significantly higher (12.98 kg ha-1) available phosphorus was observed with the application of phytase @ 720 IU (16.14 kg ha-1) and phosphatic fertilizer @ 100 kg ha-1within 24 hours of incubation over initial available P (5.20 kg ha-1). Application of 480 IU phytase resulted in significantly higher available P (51.98 kg ha-1) which was at par with 720 IU (50.45 kg ha-1). However, combined application of either 480 or 720 IU phytase along with either 50 or 100 kg P ha-1 through single super phosphate (SSP) had in statistically at par results for available phosphorus. Higher cumulative available phosphorus was recorded with the application of phytase @ 720 IU along with 100 kg P ha-1 through SSP (247.23 kg ha-1) throughout the incubation period. Further phosphorus release potential indicated that application of phytase @ 720 IU along with 100 kg P ha-1 through SSP mobilized 0.65 kg ha-1 day-1 phosphorus.