秸秆还田和氮肥减施对稻田温室气体排放的影响

Effect of Straw Returning and Nitrogen Fertilizer Reduction on Greenhouse Gas Emissions in Rice Fields

为探究在连续秸秆还田条件下氮肥减施对稻田温室气体排放的影响,于2022年在黑龙江省前进农场科技示范园区进行了8年的定位试验;共设7个处理:无秸秆及氮肥施加、施加氮肥、施加秸秆、施加秸秆且常规施氮、施加秸秆且减施10%氮肥、施加秸秆且减施20%氮肥、施加秸秆且减施30%氮肥,以无秸秆及氮肥施加为对照,对水稻生长期内温室气体排放情况进行比较。结果表明,与施加秸秆且常规施加氮肥处理相比,施加秸秆且减施10%氮肥处理、施加秸秆且减施20%氮肥处理、施加秸秆且减施30%氮肥处理的CO_(2)累积排放量分别显著降低20.00%、40.00%和49.43%,CH_(4)累积排放量显著降低16.30%、20.21%和28.80%,N_(2)O累积排放量显著降低48.76%、60.03%、67.74%;全球增温潜势显著降低37.75%、46.90%和54.93%,温室气体排放强度分别显著降低32.59%、39.79%和51.51%。在秸秆还田条件下,氮肥减施会降低水稻产量,在该试验条件下,氮肥减施10%时温室气体排放量降低且水稻产量不会受较大影响。

In order to explore the impact of nitrogen fertilizer reduction on greenhouse gas emissions in paddy fields under the condition of continuous straw return,an eight-year positioning experiment was carried out in the Qianjin Farm Science and Technology Demonstration Park in Heilongjiang Province in 2022.In the experiment,there were seven treatments:straw-free and nitrogen fertilizer application,nitrogen fertilizer application,straw application,straw application and routine nitrogen application,straw application and 10%nitrogen fertilizer reduction,straw application and 20%nitrogen fertilizer reduction,straw application and 30%nitrogen fertilizer reduction,and the greenhouse gas emissions during the rice growing period were compared with straw-free and nitrogen fertilizer application.The results showed that compared with straw and conventional nitrogen fertilizer treatment,the cumulative CO_(2)emissions were significantly reduced by 20.00%,40.00%and 49.43%,respectively,in the treatments of straw application and 10%nitrogen fertilizer reduction,straw application and 20%nitrogen fertilizer reduction,straw application and 30%nitrogen fertilizer reduction,the cumulative emissions of CH_(4)were significantly reduced by 16.30%,20.21%and 28.80%,and the cumulative emissions of N_(2)O were significantly reduced by 48.76%,60.03%and 67.74%respectively;The global warming potential was significantly reduced by 37.75%,46.90%and 54.93%,and the greenhouse gas emission intensity was significantly reduced by 32.59%,39.79%and 51.51%,respectively.Under the condition of straw return,nitrogen fertilizer reduction will reduce rice yield,and under this experimental condition,nitrogen fertilizer reduction by 10%will reduce greenhouse gas emissions and rice yield will not be greatly affected.