不同水肥耦合水稻温室效应及氮素利用率研究

A Study on Greenhouse Effect and Water and Nitrogen Use Efficiency Under Different Water and Fertilizer Coupling Modes

为了解水稻释放的CO2、CH4、N2O气体对温室效应的影响及其对氮肥的利用率,寻找合理的水肥管理模式,减小作物对温室效应的增强作用及过量施用氮素造成的农业大面积面源污染,于2016年在大田试验条件下,设置3种灌水方式(控制灌溉、间歇灌溉、淹灌)及4种施氮水平(140、110、70 kg/hm2、不施氮肥),研究了以上12种组合对水稻产量、收获指数、温室气体排放量、温室效应、水分及氮素利用率的影响,研究结果表明:施氮量的增加能有效增加水稻产量,其中控制灌溉模式下水稻产量的增加极为显著;不同灌溉模式对水稻秸秆产量的影响较小;淹灌模式下,不同施氮水平对水稻穗粒数的影响较小,为66左右。不同灌溉模式下高施氮量的CO2、CH4、N2O单位产量气体排放量均小于对照组;CH4产生的温室效应远大于CO2和N2O,不同灌水方式气体总温室效应的均值大小为淹灌>控制灌溉>间歇灌溉,说明节水灌溉有助于降低作物对大气产生的总体温室效应;水稻氮素利用率随施氮量的增加而呈现降低的趋势。

In order to understand the effect of CO2,CH4 and N2 O gas released by rice on the greenhouse effect and its utilization rate of nitrogen fertilizer,to find a reasonable water and fertilizer control mode,and to reduce greenhouse enhancement effect of crop and large area non-point source pollution due to the excessive use of nitrogen,the experimental study with 3 irrigation modes（ control irrigation,intermittent irrigation,flood irrigation） and 4 nitrogen application levels（ 140,110,70 kg/hm2,no nitrogen fertilizer） were conducted in 2016 under field conditions. The effects of the above 12 combinations on rice yield,harvest index,greenhouse gas emission,greenhouse effect,water and nitrogen use efficiency were studied. The results show that the increase of N can effectively enhance rice yield and the control irrigation mode has significant effect of yield increase; different irrigation patterns have less effect on the yield of rice straw; under the submerged irrigation mode,the effect of different nitrogen application rates on the number of grains per spike is small,which is less than 66 or so; for different irrigation modes,the emission per unit area of CO2,CH4 and N2 O of the high nitrogen application treatment is lower than that of the control group; the greenhouse effect produced by CH4 is much larger than that of CO2 and N2 O; the order of the total greenhouse effect of different irrigation methods from large to small is flooded irrigation,control irrigation,intermittent irrigation,which indicates that water-saving irrigation can reduce the overall greenhouse effect of the crop to the atmosphere and the nitrogen utilization rate of rice increases shows a downward trend with the increase of nitrogen.