Abstract:
Composting of organic proportion of solid waste increases the efficiency of waste management and produces a product that can be used as a growth medium for plants. Similarly, sewage sludge also contain nutrients and makes sludge an effective soil amendment. Both these amendments increase productivity of crops because of micronutrients and organic constituents, which serve as a beneficial soil conditioner. Aim of this research was to study the nutritional values of solid waste compost and sewage sludge and compare the results to identify the best soil amendments for plant growth. White beans (Phaseolus vulgaris) were grew using different ratios of sewage sludge and compost in the pots. The sewage sludge/compost were added to the soil at the ratios of 25, 50, 75, and 100% and mixed thoroughly, keeping 250g in three replicates. Compost and sewage sludge properties were measured before and after the growth. The pH, electrical conductivity, moisture content and particle size fell in the optimum values except for the maturity indices of the compost and sludge that was 12.5 and 8.49 respectively, above the permissible limits. The germination rate was measured by counting the plants germinated each day and length was measured on a weekly bases to identify the uptake of nutrients. The leaves were tested after 30 days of sowing for measuring the chlorophyll content. After a period of two months, plants were uprooted and nutrient analysis was done. Root and shoot length were measured. Plant phosphorus were measured after harvesting the plants. Higher shoot length was observed in 100% sewage sludge and 25% compost was 23.81cm and 23.35cm respectively. Plants grew in 75% compost and sludge showed significantly distinct root length (p<0.05). Fresh and dry Biomass of plants were directly proportional to the concentration of compost while it showed an inverse relationship for sewage sludge (p<0.05). In 100% of compost and sewage sludge, compost had the lowest chlorophyll content, while opposite results were observed for sewage sludge. Phosphorus concentration increased with increasing sewage sludge whereas, it was decreased with increasing amount of compost. From the whole study it was concluded that plants were showed equally better growth in sewage sludge as well as compost.
