Compost Preparation Technique Standardization for Raw Material Mixture of Rice Straw and Rice Husk in Bulk Amount

Rice straw and rice husk are easily available raw material at village level for farmers in huge quantity. It can be used for preparation of useful compost which would be utilized by farmers at their own field. With this objective compost has been prepared from rice straw and rice straw-rice husk mixture to study the quality of compost produced, the technique and time taken for its preparation in bulk amount. These two ingredients were taken in seven different ratios to study the effect of rice husk on the rate or time taken for compost preparation. In order to decrease the production time for compost some ingredients viz. soil dust, cow dung, urea, SSP were added with the mixtures at a same ratio in all the seven material mixtures. Time taken for compost preparation from rice straw singly and in combination with rice husk varied from 41 to 88 days depending on the ratio of the two material mixture used. Time taken for compost preparation from only rice straw was found 88 days. Rice straw-rice husk mixture in the ratio of 1:1 (w/w) with 10% cow dung, 10% soil, 1.0% urea and 0.5% SSP took least time (41 days) for preparation of compost with 49.6% weight and 43.2% volume output with respect to initial values. Reduction in weight and volume output was observed for seven mixtures including only rice straw and it was varied from 36.4 to 49.6 % and 32.1 to 43.2 % respectively with respect to the initial weight and volume of the material . Strong significant negative correlation (at 1% level) was found between the compost preparation time and rice husk content in the material mixture (R² = 0.880***). Strong significant positive correlation (at 1% level) was found between the weight and volume output of compost with rice husk content in the material mixture (R² = 0.903*** and 0.892*** respectively). Nutritional status of compost prepared from rice straw and rice husk was estimated. Composite sample of compost prepared from six treatments and sample of compost prepared from only rice straw contained high amount of available nitrogen (876.8 and 859.8 ppm respectively) and available phosphorus (456.3 and 196.9 ppm respectively). C/N ratio of compost prepared from rice straw and rice husk mix and only rice straw was found 13.9 and 14.3 respectively. Operational cost including material and labour for preparation of 1778 kg dry compost from 3849 kg rice straw and rice husk raw material (dry) was found Rs. 4.18 per kg.