The effects of Chinese milk vetch returning with nitrogen fertilizer on rice yield and greenhouse gas emissions

Fertilizer management and straw returning are effective measures to regulate greenhouse gas emissions and increase crop yields, which have attracted wide attention in agricultural production. To clarify the effect of Chinese milk vetch returning with nitrogen fertilizer on rice yield and greenhouse gas emissions in paddy field, field experiments were conducted during 2017-2018 and four treatments were proposed in this study, including the treatments with Chinese milk vetch returning plus different nitrogen fertilizer application amount, namely RA, RB, RC, and control CK (winter fallow without Chinese milk vetch returning). The results showed that treatments RA, RB, and RC significantly increased the early rice yield by 15.35%, 12.94%, and 15.35%, respectively (P<0.05), and treatment RA had the best effect on the annual yield (P<0.05) compared with control CK. Meanwhile, all the treatments with Chinese milk vetch returning plus nitrogen fertilizer increased the global warming potential, but the difference between RA, RB, and control CK was not significant (P>0.05); the greenhouse gas intensity produced by RA was 11.76% lower than control CK. In summary, treatment RA, followed by RB, had the best effect in increasing rice production and reducing greenhouse gas emissions in paddy fields. (c) 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.