Slow Released Fertilizer of Fe2+ and Mn2+ from Composite Micronutrient Chitosan-Silica

Abstract

Bertha Mangallo, Anwar Mallongi, Ishak Musaad, Sartji Taberima.

This study aims to synthesize slow released fertilizer in the form of Chitosan-Silica micro nutrient composite (CSiMN) by utilizing mining waste as a source of micronutrients whose release can be controlled by the presence of silica ash supporting material in rice chitosan as chelating from agricultural and fishery industrial wastes. The research method includes the synthesis of composite fertilizers in the ratio of chitosan: silica: tailings extract (TE) which is 1:1:2; 1:2:2; 1:3:2; 1:4:2 (v/w/v); swelling capacity test, and water retention capacity test from soil containing CSiMN composite fertilizer. The results showed that the CSiMN composite pellet in formula 1: 2: 2 was stable for 8 days in incubation with 100 mL distilled water. The ability to absorb water (swelling ratio) of chitosan silica composites in all comparisons, increased until the 120th minute and tended to be constant after the 120th minute. Chitosan-silica-ET composite at a ratio of 1: 2: 2, is the composition with the highest swelling power. The water retention capacity of soils containing CSiMN composite fertilizers is higher than soils without composite fertilizers. Increased silica composition in CSiMN composites can improve the retention of water capacity in soil. The release profile Fe2+ is different from Mn2+. After an incubation time of 20 days, the release of Fe2+ has increased while the release of Mn2+ tends to be constant.