Recycling of organic wastes in Brazil: composting, substrate and fertilizer manufacture

摘要

Large amounts of waste are produced in Brazil. Since most organic wastes produced in Brazil are not disposed of adequately, compost end-products are an economic and environmental way to recycle nutrients. When mixed appropriately, organic wastes alsogenerate rich nutrient composts that could be used to produce substrates and fertilizers. Waste inventory and factors regulating the composting process are discussed in this manuscript by covering the following issues: 1, the waste inventory includes manures, plant residues, industrial and agro industrial wastes and postharvest residues of coffee, sugarcane and eucalyptus; 2, best mixing of wastes to control pH, C/N ratio, N levels and other biological, chemical and physical factors that regulate composting process; 3, changes in the composition and in the main characteristics of composts to optimize the manufacture of substrates and high agronomic value fertilizers; 4, use of renewable wastes as a substitute for peat and vermiculite in substrate production; and 5, factors controlling the production of high agronomic value organic and organo-mineral fertilizers, mainly those associated to pH, amounts and forms of N, P and K fertilizers and raw materials mixed in industrial plants with different humified organic matrices. Recycling of substantial amounts of organic wastes produced in Brazil may have important benefits for crops, the environment and the Brazilian economy.