Properties of slow release magnesium and calcium nitrate tablets composed of rice-husk-ash with chitosan coating, within water and in several types of soil

Abstract

Preparation and characteristic of slow release tablet from environmental friendly material has been intensively studied. This current study focused on preparation of slow release tablet of magnesium and calcium nitrate. A mixture of sago starch, rice husk ash, hot water, magnesium and calcium nitrates gave compatible composite to prepare stable tablet. The higher sago starch in the composite gave the more stable tablet but with 20% sago content, tablets will survive at least 11 days in water. Magnesium and calcium release faster within distillate water than in soil. In media either water and soil, magnesium release rate was than rate of calcium release. Magnesium was found less available in RYP soil environment than in entisols and alluvial soil system.