Development and Evaluation of Agricultural Waste-Based Eco-Fertilizers.

Development of fertilizers produced from agricultural and non-agricultural solid wastes (NASW) with fixed ratios of nutrients for plant growth have a number of benefits. These fertilizers are a beneficial alternative to chemical fertilizers for many reasons, including a reduction of energy inputs from fertilizer production, as well as environmental benefits such as increasing soil organic matter, and improving soil bulk density and hydraulic conductivity. This study compared different combinations of NASW, such as spent coffee grounds and composted forestry by-products, with poultry manures to determine the feasibility of developing eco-fertilizers.  A greenhouse study was conducted  to determine the impact of the eco-fertilizer treatments on Kentucky bluegrass plant growth and biomass yield.  In addition, a soil incubation study was established to determine the effect of the eco-fertilizers on soil nutrient dynamics.  Results of the studies show that the eco-fertilizer treatments produced higher grass yields than chemical fertilizers. Composted by-products showed very little carbon mineralization, and the addition of spent coffee grounds increased the CO₂-C evolution substantially. Overall, the eco-fertilizers were easily produced and proved to be a promising substitute to chemical fertilizers.