Effect of fire on nutrient dynamics in a semi-arid grazing land ecosystem of Madurai

摘要

This study deals with the effect of fire on the nutrient dynamics of a grazing land in the semi-arid region of Madurai. The nutrient concentrations were maximum in the live shoot followed by below-ground parts, dead shoot and litter. The various nutrient accumulated in the plant components of the burned grazing land were in the order of N > K > Ca > Mg > P, whereas in the unburned site the nutrient were accumulated in the order of N > Ca > K > Mg > P. Except potassium, all the nutrient were higherin the unburned than in the burned grazing land. The uptake of nutrient from the soil was significantly higher (P < 0.05) in the unburned grazing land than in the burned grazing land. Of the total uptake, a larger amount of nutrient was transferred to above-ground parts than below-ground parts. In both the sites, the amount of nutrient returned to the soil through below-ground parts was more than through above-ground litter decomposition. The input to output nutrient ratio showed that burning of vegetation accelerates nutrient cycling.