Thermo-chemical decomposition of wheat crop residue in presence of fly--ash and its application for soil amelioration

Abstract

In the present work, pyrolysis of wheat crop residue is studied in the presence and absence of fly-ash at three different pyrolysis temperatures (viz., 2500C, 3500C and 4500C) with a temperature hold time of 1 to 4 hours. Biochar yield, in absence of fly-ash, was found to decrease with increase in pyrolysis temperature and hold time. Biochar yield was found to increase significantly with increase in fly-ash content at 2500C, whereas, a significant decrease in biochar yield was observed with increase in fly-ash content at 4500C. The biochar/fly-ash composite samples were characterized by FTIR, SEM, CHNS analysis and other physico-chemical parameters like pH, EC, alkalinity, total P, K, Na and extractable micronutrient content. pH, EC, alkalinity, total P, K and Na contents were found to be modulated by increase in fly-ash content and pyrolysis temperature. Further, effect of the biochar/fly-ash composites on the soil amelioration were studied and found to have a significant effect on soil physico-chemical properties like, water holding capacity (WHC), pH, EC, CEC, exchangeable cations, organic carbon, available P and micronutrients content