Weixin Ding Jiafa Luo Jie Li Hongyan Yu Jianling Fan Deyan Liu. Effect of long-term compost and inorganic fertilizer application on background N₂O and fertilizer-induced N₂O emissions from an intensively cultivated soil. Science of The Total Environment 2012http://dx.doi.org-10.1016-j.scitotenv.2012.11.020

Abstract

The influence of inorganic fertilizer and compost on background nitrous oxide (N₂O) and fertilizer-induced N₂O emissions were examined over a maize–wheat rotation year from June 2008 to May 2009 in a fluvo-aquic soil in Henan Province of China where a field experiment had been established in 1989 to evaluate the long-term effects of manure and fertilizer on soil organic status. The study involved five treatments: compost (OM) fertilizer NPK (nitrogen–phosphorus–potassium NPK) half compost N plus half fertilizer N (HOM) fertilizer NK (NK) and control without any fertilizer (CK). The natural logarithms of the background N₂O fluxes were significantly (P < 0.05) correlated with soil temperature but not with soil moisture during the maize or wheat growing season. The 18-year application of compost alone and inorganic fertilizer not only significantly (P < 0.05) increased soil organic carbon (SOC) by 152% and 10–43% (respectively) but also increased background N₂O emissions by 106% and 48–76% (respectively) compared with the control. Total N in soils was a better indicator for predicting annual background N₂O emission than SOC. The estimated emission factor (EF) of mineralized N calculated by dividing annual N₂O emission by mineralized N was 0.13–0.19% significantly (P < 0.05) lower than the EF of added N (0.30–0.39%). The annual N₂O emission in the NPK HOM and OM soils amended with 300 kg ha^− 1 organic or inorganic N was 1427 1325 and 1178 g N ha^− 1 respectively. There was a significant (P < 0.05) difference between the NPK and OM. The results of this study indicate that soil indigenous N was less efficiently converted into N₂O compared with exogenous N. Increasing SOC by compost application then partially increasing N supply to crops instead of adding inorganic N fertilizer may be an effective measure to mitigate N₂O emissions from arable soils in the North China plain.