Comparative assessment of crop residues: Quality characteristics and decomposition dynamics

The study aimed to explore the decomposition rate and nutrient quality of vermicompost prepared from different crop residues. An experiment on, “Influence of Crop Residues on Quality and Decomposition Rate of Vermicompost” was carried out from June to October in the year 2023-2024 at Organic Farming Research and Training Centre, Vasantrao Naik Marathwada Krishi Vidyapeeth, Parbhani with nine treatments as different crop residues viz., soybean straw, rice straw, wheat straw, sun hemp stalk, foxtail millet straw, pigeon pea stalk, cotton stalk, combination of available crop residues and control (conventional pit method of vermicomposting) i.e. 75% crop residues and 25% dung slurry. The experimental findings indicated that the vermicompost prepared from soybean straw waste required significantly the lowest number of days (64) for vermicomposting which was followed by sunhemp stalk (69). The significantly highest rate of decomposition was found in soybean staw (56%) followed bySunhemp stalk (52.5%). The pH of soybean straw (T1) during vermicomposting was considerably lower than that of all other crop residues (7.39, 7.19 and 7.08 at 30 DAF, 60 DAF and at maturity respectively). Soybean straw (T1) vermicompost had EC significantly greater than all other treatments at maturity. The significantly highest total organic carbon (35.12%) was seen in pigeon pea stalk vermicompost (T6) at the maturity stage. The lowest C:N ratio was observed in soybean straw vermicompost (T1) (17.04).The significantly highest total N content 1.87% of soybean straw (T1) vermicompost was found to be high, in contrast to all other crop wastes, P (1.27%) and K (1.79%) were found to be greatest in rice straw (T2) and cotton stalks (T7), respectively. Vermicompost prepared from residues of soybean straw (T1) had increased the number of bacteria up to 54 x 107 CFU g-1 and actinomycetes up to 36 x 105 CFU g-1 at maturity, which is considerable over other crop residues. At the maturity phase, vermicompost prepared from cotton stalks, the population of the fungus was highest in (T7) with 35 x 104 CFU g-1.