Ex-situ paddy straw management using partially aerated static pit composting approach

Aeration is a critical factor for composting which provides oxygen, controls temperature, and removes excess moisture for the biological processes. An experiment was conducted to study the effect of partially aerated static pile approach for ex-situ composting of paddy straw on physical, chemical, C/N ratio and microbial properties of the compost at 60 and 150 days. The pits containing paddy straw mixture were equipped with perforated horizontal and vertical pipes for aeration and water supply. The pits were covered with different materials such as plastic sheets, farmyard manure (FYM), soil, rugs, paddy straw, and ‘without cover’ to retain the moisture during composting. Covering with FYM, soil, and paddy straw resulted in higher degradation in terms of C/N ratio and higher nutrient content of compost. The use of FYM as cover during composting resulted in the highest values forN(1.9%),P(0.63%), K(2.4%), micronutrients [Fe(202ppm), Zn(288ppm), Mn(1626ppm) and Cu(514ppm)], bacteria, fungi, and actinomycetes count (8.86, 5.54 and 6.94 log CFU/gm, respectively) and highest degradation with C/N ratio of 17.0 after 150 days. It was concluded that partial aeration is an economic option to reduce period of composting from 9 to 5 months with FYM. This practice ensures an opportunity for farmers for ex-situ composting of paddy straw as an alternative to burning.