A long-term experiment on effect of organic manure and chemical fertilizer on distribution,accumulation and movement of NO3-N in soil

A 18 years' fertilizer experiment was conducted in cumulic cinnamon soil to study the distribution,accumulation and movement of NO3-N in 4 m depth profile with application of organic manure combined chemical fertilizer in the winter wheat corn crop system per year The results showed that NO3-N was mainly accumulated in 0 to 100cm depth soil profiles for most treatments, and total amount of NO3-N in the soil profiles was related to the N rate There were two peaks of NO3-N accumulation in the high N (120 kg/hm2) and low N (26 kg/hm2) treatments with or without organic manure, and the content of NO3-N at the depth of 4 m layer was over 10 mg/kg Suitable fertilizers rate, application of organic manure, and organic manure combined chemical fertilizer with a proper ratio is the effective ways to control accumulation of NO3-N in soil profiles and leaching loss