Evaluation of selected physical, chemical properties and nutrient quality of vermicompost from different feedstocks

Abstract

Vermicompost is a nutrient-rich organic fertilizer that contains macronutrients, micronutrients, beneficial soil microflora, and plant growth regulators. An experiment was conducted at the Vermiculture Center, College of Agriculture, Hawassa University, Ethiopia in 2023 to assess the impact of feedstock type on selected physicochemical properties and nutrient composition of vermicompost. Common bean straw, coffee husk, maize stalk, and enset leaves were used as feedstock materials individually and in various combinations. The feedstocks were mixed with cow dung at a 2:1 ratio based on dry weight and arranged in a completely randomized design. Each 30 kg feedstock in the worm bin was supplied with 500 grams of Eisenia fetida earthworms. Upon maturity, the vermicompost was harvested by removing earthworms and other materials through a 4-mm sieve. Results showed significant differences in the physicochemical properties of vermicompost derived from different feedstocks. Common bean straw + cow dung reached maturity the fastest (66 days), while maize stalks + cow dung took the longest (85 days). The combination of common bean straw + coffee husk + cow dung yielded the highest vermicompost output (13.8 kg), while the lowest output (10.8 kg) was obtained from enset leaves + cow dung. Organic carbon content decreased by 39-100% in vermicompost compared to the original feedstock, while total nitrogen content increased significantly by 59-157%. The study concluded that the common bean straw + coffee husk + cow dung combination produced vermicompost with the best physicochemical properties and nutrient composition, and hence recommended choice for vermicompost production.