Comparative effect of polymer coating materials on physical properties of NPK fertilizer pellet

Research and Technology Center for Application of Isotope and Radiation-BRIN, Jl. Lebak Bulus Raya No. 49, Jakarta 12440, Indonesia

^* Corresponding author: gatot2811@yahoo.com

Abstract

Slow-release fertilizer is one method to reduce the rate of loss of fertilizer from the soil due to leaching by rainwater or irrigation water. One of the agents that can be used for slow-release fertilizers is polymeric materials coated on NPK fertilizers. The NPK fertilizer coating polymer material used was a mixture of starch, acrylamide, PVA, and chitosan that was formulated and irradiated at a dose of 20 kGy. The purpose of this study was to obtain the best comparison between coating materials and NPK fertilizers made with a pelletizer machine. NPK fertilizer is mashed and mixed with polymer coating material with a weight ratio of NPK coating material/fertilizer; 1/9, 2/8, and 3/7. The results obtained showed the largest pellet yield capacity using a ratio of coating material and NPK fertilizer with a weight ratio of 1/9 of 4.28 g/minute and the greatest durability value at a ratio of 3/7 with a value of 87.1%. NPK released in NPK fertilizer coated with a polymer coating and fertilizer in a ratio of 1/9, 2/8, and 3/7 resulted in the release of NPK with not too big a difference. In the analysis of the functional group by FTIR between non-irradiated formulation and irradiated 20 kGy, there was no addition or change of molecular structure in the functional group. whereas thermal analysis with DSC displayed endotherm at temperature 500C to 1200C and exotherm at temperature 2500C until 3200C for analysis of TGA degradation of the formulation is divided into 2 phases, in the first phase degradation begins at a temperature of 500C to 1500C losing weight of 5% and in the second phase of degradation at 250⁰C to 500⁰C losing weighs 47%