Variation in physicochemical characteristics during co-composting of vegetable waste with animal manure using different composting techniques

Abstract

The organic component of municipal solid waste consists of mainly kitchen wastes with almost 50 % of the total solid waste generation. Composting of kitchen waste is a good strategy towards management of solid waste and sustainable agricultural production. The main objective of the present study was to determine the bests mixing ratio of garden soil, vegetable waste and three different types of animal manures- poultry, swine and cow manure. The study was carried out using three different methods- bin, pit and windrow composting to produce stable and mature composts. Thermophilic temperature in all the composting feedstock during composting was recorded to be almost equal to or greater than 55 °C indicating removal of pathogens and heavy metals. The average OC, TN and AP in the composts was maximum in bin composting, although there was a declining trend from the initial till final compost stage. The composts obtained from 1:3:1.5 ratio of soil: vegetable waste: manure, recorded average maximum germination percentage with 88.67 % in poultry manure mix, followed by 73.33 % in cow manure mix. However, in swine manure mix composts, the 1:2:1 ratio recorded maximum germination percentage among the three different ratios. In between the three types of composting methods the average germination percentage was maximum in bin composting with 74.81 % followed by pit composting with 69.63 % and minimum in windrow composting with 60 %. The effectiveness of the composting methods was bin> pit > windrow and performance of manure was poultry> cow> swine.