Abstract

                                Phosphorus nutrition plays a significant role in the growth and yield of crops,but it is the most deficient nutrient in the soil. Coating of the phosphorus (P)fertilizers can control the release of nutrients and improve the efficiency. Inthis study organic acids such as humic acid and fulvic acid are used as thecoating material for gradual release of P from the Di ammonium phosphate(DAP) fertilizer. In the present investigation Brinjal (Var. CO2) was used as thetest crop. The study emphasizes enhanced phosphorus use efficiency (PUE)along with improved growth of brinjal at different rates of organic acids (Humicacid and Fulvic acid) coated DAP in comparison with uncoated DAP. In theincubation experiment the release pattern of P in soil from different coatingconcentrations (0, 5, 10, 15, 20%) was tested under controlled conditionand the growth and PUE were tested under field conditions. Results showedthat at 60 days of incubation T9 (20% HA coated DAP) showed maximumP release and the application of NK+P as HA coated DAP (20%) increasedplant height, number of leaves, leaf area, dry matter production and PUE inbrinjal. These results proved that organic acid coated DAP could be used asan effective fertilizer to improve growth and PUE in brinjal over uncoated DAP

Key words : Humic acid; Fulvic acid; Incubation study; Growth; PUE