EFFECT OF POULTRY LITTER AND COW DUNG SUPPLEMENTATION ON THE BIOCONVERSION OF SOLID MUNICIPAL WASTE TO ORGANIC FERTILIZER

Abstract

The suitability of poultry litter, cow dung and leguminous plant supplementation in the bioconversion of solid municipal waste to organic fertilizer using indigenous microorganisms was investigated. The windrow method of composting was adopted and five mesocosms designated cell I, II, III, IV and V were used. One hundred and twenty kilogram of solid waste which included municipal solid waste, grasses and leaves were distributed into the various mesocosms. Cells I, II and III were supplemented with poultry litter, cow dung and leguminous plants respectively. A combination of all the three supplements was added to cell IV while Cell V received no supplement. Each of these were allowed to compost for 90days. Average temperature values ranging from 39-51oC, 38-52oC, 31-48oC, 39-60oC and 32-42oC were recorded in cells I, II, III, IV and V respectively, throughout the composting duration. It was observed that total organic carbon, organic nitrogen and pH values decreased progressively with increase in composting duration. The pH values obtained decreased from 8.2 to 5.09 (cell I). 9.32 to 6.02 (cell II), 7.52 to 6.21 (cell III), 10.28 to 5.30 (cell IV) and 7.52 to 6.93 (cell V). At the end of composting, products of high nutrient value though to varying degree were obtained in various cells. The nutrient composition in cell I supplemented with poultry litter was 9.8mg/g (nitrate), 2.05mg/g (ammonium-nitrogen), 8.4mg/g (phosphate) and 0.04 mg/g (sulphate). Nutrient values of product obtained in cell II were 37.8mg/g (nitrate), 10.46 mg/g (ammonium-nitrogen), 15.82mg/g (phosphate) and 1.89mg/g (sulphate). In cell III, the values of nitrate, ammonium-nitrogen, phosphate and sulphate were 21.4, 5.73, 9.13 and 0.62 (mg/g) respectively. Highest values were obtained in cell IV with 85mg/g nitrate, 97mg/g ammonium-nitrogen, 28.4mg/g phosphate and 1.03mg/g sulphate. Loamy soil amended with the various produced compost, significantly influenced growth and development of bean seed used as indicator crop. Amendment of soil with NPK 15:15:15 yielded 15.3cm increase in leaf length and 8.25g crop dry weight. Analysis of variance indicated that there was a significant difference among the efficacies of various product as well as NPK fertilizer. However, t-test showed that there was no significant difference between the efficacies of product obtained from cell IV and NPK fertilizer. Simultaneously composting these wastes would act as potential sustainable environmentally friendly route of solid waste management and disposal as well as value added organic fertilizer for agronomic use.