Studies on Organic Polymer Coated DAP Fertilizer on Phosphorus and Nitrate Releasing Pattern in Calcareous Soils
N. S. Arunima *
Department of Soil Science and Agricultural Chemistry, TNAU, Tamil Nadu Coimbatore-641003, India.
R. Shanmugasundaram
Department of Soil Science and Agricultural Chemistry, TNAU, Tamil Nadu Coimbatore-641003, India.
D. Selvi
Department of Soil Science and Agricultural Chemistry, TNAU, Tamil Nadu Coimbatore-641003, India.
N. O. Gopal
Department of Agricultural Microbiology, TNAU, Tamil Nadu, Coimbatore–641003, India.
*Author to whom correspondence should be addressed.
Abstract
An incubation experiment was carried out with DAP coated with chitosan and sodium alginate organic polymers. Treatments comprises of T1: Chitosan coated 75% DAP, T2: Chitosan coated 100% DAP, T3: Sodium alginate coated 75% DAP, T4: Sodium alginate coated 100% DAP, T5: 100% RDF (SSP), and T6: 100% RDF( DAP) which were replicated four times in completely randomized block design. Results revealed that 100% chitosan coated DAP (T2) was found to be superior than all the remaining treatments which was followed by 100% sodium alginate coated DAP (T4). Uncoated DAP and SSP high leachate P in the early stage of incubation study and there after P content was minimal in leachate. It was concluded that coated DAP had less release of P at the start of study and thereafter steady state because of the dissolution of P through the coated membrane. Similar trend was observed in nitrate releasing pattern.
Keywords: Incubation, organic polymers, chitosan, sodium alginate, leachate P and NO3 –N