Production of Organic Fertilizer from Solid Waste and Its Utilization in Intensive Organic-Based Vegetable Production and for Sustaining Soil Health and Productivity
Improper solid waste disposal poses a major threat to the environment and high risks to human health. Most of these wastes are biodegradable and can be converted into valuable resources that reduces their otherwise negative impacts. The Central Luzon State University (CLSU) has devised ways to convert solid wastes into a valuable resource — organic fertilizer — and its subsequent utilization as a source of plant nutrients in intensive small-scale organic-based vegetable production and for sustaining soil health and productivity. Generally, the project aimed to promote proper waste management by the university via organic fertilizer production and demonstrate the feasibility of growing vegetables using organic fertilizer as the major source of plant nutrients. Specifically, it aimed to a) develop and disseminate technology on solid waste composting for the production of organic fertilizer, b) determine the efficacy with which organic fertilizer generates major nutrients for vegetable production and its effect on some soil physical properties. Shredding the substrate prior to piling shortened the decomposition process by 7 to 10 days depending on the substrate combination. Combined solid waste (buffalo manure: rice hull ash) at a ratio of 2:1:1 proved to be the best combination. When the solid wastes are composed mainly of rice straw and leaf litter, as well as their combination, the decomposition process is prolonged from 30 days to between 60 and 75 days. Economic analysis of producing 100 bags of organic fertilizer for one cycle (27-30 days) revealed a net income of US$102.35. Pure application of organic fertilizer and/or compost tea showed great potential in intensive small-scale organic-based vegetable production (lettuce, pechay, eggplant, grafted tomato) as a major source of plant nutrients.