Influence of Different Substrates on Nutrient Composition of Vermicompost and Vermiwash

The present study was conducted to evaluate the effect of different substrates on nutrient composition of vermicompost and vermiwash at Division of Soil Science, College of Agriculture, Pune during 2022-23. High density polyethylene beds of 12 X 4 X 2 feet size were used for production of vermicompost. While 200 liter capacity plastic barrels were employed for vermiwash preparation. There were five treatments of substrate combination like 25% rain tree litter (RTL) + 75% paddy straw spent mushroom compost (PSSMC); 50%tree litter+50% paddy straw spent mushroom compost (PSSMC); 75% tree litter+25% paddy straw spent mushroom compost (PSSMC); 100% rain tree litter, 100% paddy straw spent mushroom compost (PSSMC) were used for the preparation of vermicompost with earthworm Eisenia fetida and replicated four times in completely randomized block design. There were ten plastic barrels of above capacity were used for by using vermicompost prepared from different substrate combinations. The sampling, harvesting and characterization of vermiwash was done in duplicate for first and second harvest after incubation period of 15 days.

Results showed that pH, EC, organic matter, C: N ratio, total nitrogen, phosphorus, potassium, iron, zinc, manganese, copper in vermicompost were significantly influenced by different proportions of rain tree litter and paddy straw spent mushroom compost. C: N ratio of vermicompost prepared by using rain tree litter and paddy straw spent mushroom compost was ranged between 9.71 and 16.19. Significantly higher total nitrogen (2.31%), phosphorus (1.185%), potassium (0.863%), iron (1072 mg kg-1), manganese (231.50 mg kg-1), zinc (254 mg kg-1) and copper (54.25 mg kg-1) were noted in vermicompost from 100% rain tree litter. Significantly high EC (total soluble salts) at first and second harvest of vermiwash was reported when 100% rain tree litter compost and vermicompost as substrate used. Further, vermiwash prepared by using vermicompost from rain tree litter reported significantly higher nitrogen (0.65 and 0.51%), phosphorus (0.33 and 0.27%) and potassium (0.27 and 0.23%) content at both harvest respectively but higher content was in first harvest. Vermiwash prepared from 100% raintree litter vermicompost reported significantly higher Fe, Mn, Zn and Cu content at both harvesting stage.