ENHANCING THE PRODUCTIVITY OF SOIL AND SUGARCANE CROP BY EFFECTIVE RECYCLING OF SUGAR INDUSTRIAL WASTES IN THENI DISTRICT, TAMIL NADU

摘要

Effective recycling and utilization of Sugar industry based big-products viz., pressmud, bio compost, distillery effluent / spentwash as source of nutrient in agriculture is highly essential to make the sugar industry economically more viable. Laboratory incubation, pot culture studies and field experiments were conducted in a phased manner during (2005 08) at Agricultural College and Research Institute, Madurai to characterize and recommend standard doses of application and evolve suitable reclamation technologies utilizing the sugar industry wastes. The results of the experiment indicated that one time application of raw distillery spentwash @ 125m~3 ha~(-1) in calcareous sodic soils of somayanur soil series (Calcic Natrustalfs ) in Theni district was effective in reducing the soil ESP levels to below 15, improving the available nutrient status and recording a maximum sugarcane yield of 118.6 to 130.8 t ha~(-1) in the major sugarcane growing blocks of Theni district. Further the Sugarcane crop (Co 86249) responded well to 1:40 dilution of spentwash as source of irrigation after the tillering phase (105 days after planting) in sandy loam soils of Andipatty block. Studies conducted with various sources of organic manures proved that application of pressmud based biocompost along with 75% recommended NPK fertilizers in Irugur soil series recorded a maximum cane yield of 132 t ha~(-1) which was on par with other organic manures (FYM @ 12.5 t ha~(-1), Green leaf manure 6.25 t ha~(-1)) with 100% recommended dose of fertilizers, resulting in saving of 25% chemical fertilizers. India is the largest producer and consumer of sugar in the world. Among the several industries, sugar industry plays a major role in contributing to the economic development and employment generation of the country. The 453 sugars factories in India produce about 20.0 million tonnes of sugar besides providing employment opportunities to 2 million people either directly or indirectly. Tamil Nadu is one of the leading producers of sugar in the country and its contribution is about 7% of countrys total sugar production. There are 46 sugar mills in Tamil Nadu which produces 16.5 lakh tonnes of total sugar (2010-11). There are about 329 distilleries in India producing 30-40 billion litres of spentwash from 3.2 billion litres of alcohol per annum. The raw spentwash is acidic in nature, with high BOD and COD. Biomethanation is one of the best options for spentwash treatment and the post methanated spentwash is rich in plant nutrients and can be used as liquid manure. Untreated raw spentwash is used as one time application for sodic soil reclamation whereas with dilution it is recommended for seed hardening treatment and also as a liquid manure for dryland soils and crops. Bio compost prepared by using spentwash and pressmud in the ratio of 1:2.5 was neutral in pH with an EC of about 2.5 dsm~(-1), organic carbon content of 21% and a C:N ratio of about 12:1. It is a good source of organic manure rich in N, P, K and micronutrients. Field experiments were conducted in three major soil series of Theni district viz., Somayanur, Palaviduthi and Irugur with sugarcane CoC86032 as test crop to evaluate the efficacies of the industry by-products and also to standardize the doses of application for various purposes. Characteristics of the soils are presented in Table 1. The objectives of the research trials were to standardize the dose for one time application of DSW in calcareous sodic soils and fixing the right dilution for irrigating sugarcane and to test verify the response of the crop to biocompost application with various levels of inorganic fertilizers.