Microbial Interventions for Composting of Organic and Lignocellulose Waste

Abstract

Composting of paddy straw (PS) and vegetable waste (VW) was carried out by using different microbial inoculants. Four microbial treatments were designed namely fungal consortium (Aspergillus, Trichoderma), fungal cum bacterial consortium (Aspergillus, Trichoderma, Bacillus, Pseudomonas, Azotobacter, Delftia) and two commercial preparations namely Waste Decomposer and Kayakalp. Pit composting was carried out at soil research farm using pits of 1.5 × 1.2 × 0.3 m dimensions located at 30.9° N, 75.8° E. Attempt was made to carry out composting in these shallow pits but because of lesser total volume only mesophilic composting could be established with no thermophilic phase. Two substrate combinations – 40% PS + 60% VW (Set I) and 70% PS + 30% VW (Set II) were taken 40 kg per pit (fresh weight basis) and 15% inoculum for composting in February to April 2019. In Set I, after 90 days, lowest C% (29.33), highest N% (1.85) and lowest C : N ratio (15.85) were obtained with fungal cum bacterial consortium. In Set II, after 90 days, lowest C% (29.24), highest N% (1.48) and lowest C : N (19.76) were obtained with fungal cum bacterial consortium. After a curing period of 30 days, Set I inoculated with fungal cum bacterial consortium proved to be the best with pH of 8.19, electrical conductivity of 1.52 dS/m, moisture—45%, carbon—29.13%, nitrogen—1.86%, phosphorus—0.44%, potassium—4.06%, C : N ratio—15.66, volatile solids—52.22%, ash—47.78%, crude proteins—7.87%, neutral detergent fibre (NDF)—56.40%, acid detergent fibre (ADF)—36.60%, hemicellulose—19.80% and a germination index of 121.29%.