INFLUENCE OF ORGANIC AMENDMENTS ON SOIL CARBON SEQUESTRATION AND FERTILITY

Abstract

Climate change is on the increase and there is a necessity to seek methods of managing agricultural operations that will not only absorb the carbon in the air, but also maintain the soil healthy and fruitful. This research systematically assessed the mechanistic mechanisms that involve integrated organic amendments, biochar, animal manure and crop residues that impact on the stabilization of carbon in the soil, aggregate processes, microbial activity and nutrient retention. We quantified carbon mineralization kinetics of the soil, Langmuir protection isotherms, manipulated Arrhenius temperature anchemmoisture responses, and catalytic efficiencies of the enzymes and greenhouse gas balances through a meta-synthesis of 180 field and mesocosm experiments and a special laboratory validation of these experiments. Biochar-recycled manure was found to be much better treated than any of the single amendments and enhanced recalcitrant carbon content (18.23 vs. 5.23 mg g -1 in control), mean residence time (267 years) and aggregate mean weight diameter (124). Biochar raised recalcitrant carbon decomposition activation energy to 79.3 kJ mol -1, which imposed a thermodynamic limit on quick mineralization, with clay loam soils having the highest Langmuir protection potential ( 256.4 0 C m -2). The joint amendment enhanced the cation exchange by 23.5 cmol + kg -1, cut down the nitrate leaching by half, and retained a positive net ecosystem carbon balance ( +18.9 g C m -2 yr -1) with 31% smaller yield downsizing global warming potential than traditional fertilization. The catalytic efficiency of 233 -glucosidase by microbes was enhanced 3-fold and phytoavailability of the heavy metal (Cd, Cu, Pb) lowered 6881%. The conclusions of these findings are that joint biochar.organic additions convert agricultural soils into net carbon sinks and increase fertility and reduce environmental risks, but the field scale functionality is dependent on soil texture, clay mineralogy and pyrolysis situation of additions. Site-specific, standardized management protocols are needed to achieve the maximum climate mitigation of this strategy.