Q-217. Influence of Sugar Industry Effluents on Changes in Soil Enzymatic Activity

M. Nagaraju, G. Narasimha (SVU), V. Rangaswamy (SKU);
Natl. P.G. Coll., Nandyal, INDIA.

The determination of some specific enzyme activities seems to be the best approach for evaluating the state of microbial activity and understanding its response to cultivation practices and environmental factors. In the present work, the influence of sugar factory wastes on soil enzymatic properties was studied both in artificially contaminated laboratory soils and in field contaminated soils. The objective of this was to measure specific enzyme activities i.e. amylase, cellulase, invertase and protease in both soils. The field soils contaminated with wastes were collected from the surroundings of sugar industry. In laboratory studies, effluent undischarged soil was treated with the doses of 10, 50 and 100% concentrations of effluents. Soil samples were brought to 60% of maximal water capacity and incubated at a temperature of 20°C. Enzymatic activities were determined after 0, 10, 20, 30 and 40 days of incubation. For the determination of the activities of amylase, cellulase, invertase and protease, the starch, carboxy methyl cellulose, sucrose and casein were used as substrates respectively. Degradation products were determined with a spectrophotometer by 750 nm for protease and 670 nm for the rest of the enzymes. The four enzymatic activities were higher in the field contaminated soils over the undischarged soils. By increasing the effluent concentration, the enzymatic activities were increased up to 50 (cellulase and amylase) and 100 (protease) percentages, where as invertase activity was decreased in artificially contaminated soils. Enzyme activities were declined with time. At the beginning of the incubation (0-30d), all the enzymatic activities were increased, to a maximum values at 30 days, then the values were decreased to near the original values. In summary, the results obtained show a higher enzymatic activities in field contaminated soils, therefore, the soil quality was improved, and as a result, its fertility. But in artificially treated soils, high concentration of effluents showed adverse effects, decreased the activities of cellulase, amylase and invertase except the protease, as a result, it did affect the soil quality.