Low Cost Traditional Cassava Starch Factory Solid Waste (Thippi) Composting: A Possible Strategy for Organic Nutrient Management and Economic Security for Tribal Farmers

Abstract

In Kerala, cassava tubers are mainly used for human consumption whereas in Tamil Nadu, it is for theproduction of industrial starch and sago. During the extraction of starch from tubers, both small scaleand large starch and sago factories are generating on an average about 40-60 tonnes of solid waste(thippi) per annum creating serious environmental pollution. Considering the voluminous quantity ofthippi discharged from these industries, we explored the possibility of making some value added organicmanures from thippi. Among the various protocols tried, the cheap and traditional way of compostingusing earthworms gave better result in making it in to a nutrient rich organic manure. It had the highestplant nutrient content with low C:N ratio (8:1). The mean N, P, K, Ca, Mg, Fe, Mn, Cu and Zn contentin thippi compost was 1.32, 3.82, 0.40, 2.18, 0.96, 1.11, 0.08%, 11.23 and 89.93 ppm respectivelywhich is 3.5, 49,7, 32.5, 8, 185, 100, 2.5 and 12 times respective of nutrients compared to rawthippi. A study on the mineralization pattern of nutrients from thippi compost under pot incubation fora period of one year indicated the maximum release of almost all nutrients during 5-7thmonth. Fieldexperiments conducted for two seasons to study the effect of thippi compost as a substitute to commonlyused organic manures and fertilizers including secondary and micronutrients revealed thippi compostas an alternative to FYM, green manuringin situwith cowpea, crop residue incorporation, vermicompostand coir pith compost and even fertilizers up to N @ 50 kg ha-1, MgSO4@ 2.5 kg ha-1and ZnSO4@2.5 kg ha-1.