Study of Release Pattern of Phosphorus in Soils: Incubated with Organic Acids and Different Origin of Rock Phosphate

In this study the hypotheses assumed was assessed through incubation study in lab. Soil samples were pre incubated at 25 °C for 1 week prior to actual incubation to stabilize the microbial activity. Moisture content of soil was adjusted to 60 % of water holding capacity by adding deionized water. There were three Rock Phosphates of origin Jhabua, Udaipur-I, Udaipur-II and eleven treatments including the control and soils were analysed at six incubation periods (15, 30, 45, 60, 90 and 120 days); with three replications to see the effectiveness of different RPs treated with organic acids and zeolite with phosphate solubilizing bacteria (PSB) viz., Pseudomonas fluorescence. The incubation experiment showed a positive impact of the organic acids and FYM with increasing days of incubation gaining highest peak at 60 days in their ability to release P from all the RP sources. Data from 45 to 60 Days After Incubation (DAI) were found most suitable for P availability point of view. URP II showed maximum available P with gluconic acid@20 mM (13.28 kg ha-1) with an increase of 39% followed by FYM @5 tonne ha-1 with available P (13.10 kg ha-1) and increase of 50.97% over control. JRP responded maximum with FYM @ 5 tonne ha-1(9.05 kg ha-1) available P with an increase of 36.35% followed by oxalic acid. The URP I maintained highest available P with oxalic acid@0.5 M (10.59 kg ha-1) with an increase of 44.51% followed by FYM @5 tonne ha-1.