Amelioration of an acidic ultisol by straw-derived biochars combined with dicyandiamide under application of urea.

摘要: The rapid increase in agricultural pollution demands judicious use of inputs and outputs for sustainable crop production. Crop straws were pyrolyzed under oxygen-limited conditions at 400 °C 2 h to prepare peanut straw biochar (PB), canola (CB), wheat (WB). Then, 300-g soils incubated each with urea nitrogen (UN) UN + biochars or without dicyandiamide (DCD) 60 days. During the incubations, soil acidification induced by was somewhat inhibited biochars, but nitrification hydrolyzed NH4 produced much more acidity than neutralization potential biochars. In single (200 mg/kg) treatment, pH decreased drastically final after incubation lower control. Antagonistic UN, all three neutralized acidity, which consistent their inherent alkalinity. DCD obvious throughout as 30 mg/kg DCD + 200 mg/kg combined 1  % PB, CB, WB retained 0.94, 0.79, 1.19 units higher pH, respectively, significantly reduced exchangeable over treatments (P < 0.05). had highly significant effects on Al3+, +-N, (NO3 −+NO2 −)-N, available P Amplified +-N retentions rates PB referred increased negatively charged sites nutrient adsorptions. Applied transformations varied among different treatments, maximum amounts total mineral N recovered 218.3, 218.5, 223.8 mg/kg presence WB, compared 198.2, 201.6, 205.2 mg/kg, no treatments. Urea severe even lowered ameliorative applied Thus, ammonium-based fertilizers must include inhibitor and, if used combination will offer a suitable choice reduce improve base saturation fertility agriculture.