[Effects of different nitrogen fertilizers on annual emissions of greenhouse gas from maize field in Northeast China].

A field experiment was conducted to investigate the greenhouse gas emission at high latitude farmland in Northeast China. We monitored the greenhouse gas emission using the static chamber-gas chromatography method. Four nitrogen (N) fertilizers were used: conventional N fertilization (CN), slow release fertilizer (SLN), urea plus nitrification inhibitor and urease inhibitor (NIUI), and no nitrogen fertilizer (NN). The results showed that the yields under CN, SLN and NIUI treatments were 9618, 9376 and 9645 kg·hm, respectively. Compared with CN treatment, SLN increased soil NO emission in the growing season and decreased NO emission in the non-growing season. The cumulative NO emission flux of NIUI treatment was 39.0% lower than that of CN. There were no significant differences in the annual cumulative CO emission flux among the treatments. The spring maize field in Northeast China was a weak CH sink. NIUI treatment promoted soil CH absorption in maize growing season compared with CN treatment. In summary, urea plus nitrification inhibitor and urease inhibitor could significantly reduce soil greenhouse gas emissions with high yield of maize.