精准农业对华北平原冬小麦温室气体排放和产量的短期影响

Short-term effect of precision agriculture on winter wheat yield and greenhouse gas emissions in the North China Plain

本试验以京郊冬小麦田为研究对象,采用大田试验设置4个处理:CTF(常规整地+常规施肥)、PF(精准施肥)、LL(激光平地)、PF+LL(精准施肥+激光平地),采用静态箱-气相色谱法分析了不同农业措施下的土壤温室气体(CO2、N2O、CH4)排放特征。结果表明:和CTF相比,LL冬小麦产量显著提高7.10%;降雨、灌溉后表层土壤含水率显著提高,冬小麦季土壤CH4吸收量显著增加22%,土壤CO2、N2O累计排放量分别显著增加27.20%、8.81%。PF产量与CTF无显著差异;土壤N2O排放峰出现在追肥后,PF排放峰值显著较CTF低15.41%,精准施肥至收获期间PF土壤N2O显著减排15.05%,但整个冬小麦生长季PF土壤CO2、N2O累计排放量和CH4累计吸收量与CTF均无显著差异。和CTF相比,PF+LL小麦产量显著提高8.2%,同时PF+LL土壤具备较好的持水性,雨季及灌溉后表层土壤含水率分别显著提高8.81%、7.63%,冬小麦生长季土壤CO2累计排放量显著增加33.53%,CH4吸收量显著增加31.5%,N2O累计排放量无显著差异,但在精准施肥至收获期间土壤N2O显著减排10.22%。综上,激光平地技术可显著增产但综合增温潜势较强,精准施肥技术对产量无显著影响,但降低了N2O排放峰值,减少了精准施肥后的N2O累计排放量,表现出一定的N2O减排潜力。

A field experiment was conducted in suburban areas of Beijing.The effect of four treatments,namely conventional tillage and fertilization(CTF),precision fertilization(PF)alone at the topdressing stage,laser land leveling(LL)alone prior to sowing,and a combination of PF+LL,on CO2,N2O,and CH4 emissions were examined.The results showed that LL significantly increased the wheat yield by 7.10%compared with CTF,and surface soil moisture content was significantly improved.Regarding greenhouse gas emissions,the amount of CH4 absorbed by soil was significantly increased by 22.00%,but CO2 and N2O emission fluxes were increased by 27.20%and 8.81%,respectively.Compared with CTF,PF had no effect on wheat yield.The peak value of N2O emissions emerged after topdressing and significantly decreased by 15.41%.The emission fluxes of N2O between the topdressing stage and harvest stage were significantly decreased by 15.05%.However,in the entire season of winter wheat,there were no differences in emissions of CO2,N2O,and CH4 found between PF and CTF.PF+LL significantly increased the wheat yield by 8.20%compared with CTF,and the water holding capacity of soil was enhanced,as the water content was significantly increased by 8.81%and 7.63%in the rainy season and irrigation season,respectively.The cumulative emissions of CO2 were significantly decreased by 33.53%.The absorbed amount of CH4 was significantly decreased by 31.50%.PF+LL also had no effect on the cumulative emissions of N2O in the entire season of winter wheat,but it significantly decreased the N2O emissions between the topdressing stage and harvest stage.In summary,LL could significantly increase the winter wheat yield,but it also increased the global warming potential.PF had no significant effect on wheat yield,but it decreased the peak value of N2O emissions,thereby showing the potential to reduce N2O emissions.In conclusion,the prospects of precision agriculture technology in increasing production and reducing emissions need to be further studied.