Abstract

                                An incubation experiment was conducted to study the influence of Humic Acid (HA) on nutrient release, organic carbon (OC) content and cation exchange capacity (CEC) of the soil. The humic acid as potassium humate was added at graded doses (20 to 80 kg ha). A linear trend in the release of NP and K was observed for the application of HA. The release of N was significant upto 20 kg of HA ha', whereas for P and K it extended upto 40 kg ha. The N and P were released for a longer I period of 60 days, while K release attained a plateau on 45 days after incubation. At the end of incubation period, there was a steep and significant increase of organic carbon and CEC upto 40 kg HA ha¹.

Key words : Humic acid, Release pattern of N, P, K, Organic carbon, CEC.