Characterization of Enriched Phosphatic Sludge and Studies on Nutrient Releasing Pattern from Enriched Phosphatic Sludge under Submerged Condition

A laboratory experiment was conducted to characterize the enriched phosphatic sludge (EPS) and to determine the nutrients release pattern from different levels of enriched phosphatic sludge under flooded condition. Soil sample were collected at the depth of 0-15 cm from “B” block, Zonal Agricultural research Station, V. C. Farm, Mandya. Soil sampling area lies between 76082'01" to 76082'08" E longitude and 12057'03" to 12057'05" N latitude with an average elevation of 699-715 m above SML and incubation study carried out during 2016 at UAS, GKVK, Bengaluru. Seven different levels of EPS (0, 125, 250, 500, 750, 1000 and 1250 kg ha-1) was adopted in this experiment with three replication by using factorial complete randomized design. Enriched phosphatic sludge supplied by Aditya Birla chemical fertilizers private limited was characterized for various parameters. The analysis of the samples revealed that the pH value of enriched phosphatic sludge was alkaline in reaction (8.03) and medium in salt content (0.97 dS m-1) and OC (11.30%).The enriched phosphatic sludge had high quantity of phosphorus (6.88%) and the total N, K, Ca, Mg and S contents were also appreciable in the enriched phosphatic sludge (1.51, 1.20, 1.50, 1.10 and 1.20%, respectively). Heavy metal content in sludge was much lower than that indicated for PROM (phosphate rich organic manure) and other organic fertilizers listed in the FCO amendment.Significantly higher available nutrients release (NPK) were recorded in treatment T7 which received 1250 kg EPS ha-1