Contrasting effects of maize straw, coal fly ash and their biochars on nutrient mineralization, enzyme activities and CO2 emissions sandy loess soil

Abstract The mismanagement uses of crop straw and fly coal ash are cause environment and economic threats, but thermal-pyrolysis is an alternative for managing that converts bio-waste into biochar, its feasibility and acceptance by public as soil amendments depends on the agronomic and environmental values compared between biochar and the raw materials. We had conducted 60 days’ short-term study, to evaluate the influence of different wastes and their derived biochars along with inorganic nutrients (NPK) on carbon dioxide (CO2) fluxes, soil enzymes activities, soil fertility status and microbial activities. There were eight treatments of soil amendments: without an amendment (CK), chemical fertilizers (NPK), maize straw waste + chemical fertilizers (MS+NPK), maize straw biochar + chemical fertilizers (MB+NPK), coal fly ash waste (Waste residue from coal to methanol + chemical fertilizers (CW+NPK), coal fly ash biochar + chemical fertilizers (CB+NPK), maize straw waste + chemical fertilizers + maize straw biochar (MS+NPK+MB) and coal fly ash waste + chemical fertilizers coal fly ash biochar (CW+NPK+CB). The results indicated that soil EC, pH, nitrate N (NO3-- N), SOC, TN and available K were significantly (p