Nitrogen fertilizer value of activated sewage derived protein: Effect of environment and nitrification inhibitor on NO 3 - release, soil microbial activity and yield of summer cabbage

摘要: Yield response of summer cabbage (Brassica oleracea varcapitata cv. Hispi F1) to N applied as organic (activated sewage sludge derived protein [Protox] and dried blood) inorganic (ammonium nitrate, ammonium sulphate, sodium nitrate urea) fertilizers was compared in relation the availability characteristics materials. Effects nitrification inhibitor dicyandiamide (DCD) on release, crop yield status were also assessed. In addition CO2 efflux measured from amended soil determine effects fertilizer application microbial activity. The sources mineralized quickly exhibited similar patterns NH4-N depletion NO3-N accumulation functions thermal-time with mineral fertilizers. However, marginally smaller (though not significantly) forms; probably because less released crop. This reflected total concentrations recoveries plants supplied fertilizer. Applied DCD increased for complete raised content crop, but had no overall effect growth. contrast which generally reduced soil, protein-based rate activity directly by raising substrate availability. Sewage provided an effective alternative nutrition whilst minimising stress environment may occur following conventional forms soil.