Effects of nitrogen fertilizer combined with nitrification inhibi-tor on growth and N2O emission of fresh maize in Hainan
[Objective]In order to provide theoretical basis for guiding the one-time base application of nitrogen ferti-lizer and reducing N2O emission in the production of fresh maize in Hainan,the effects of nitrogen fertilizer combined with nitrification inhibitor dicyandiamide(DCD)on the growth and N2O emission of fresh maize were studied.[Method]Sunuo No.6 maize was selected as test material,and a field plot experiment was conducted.There are 4 treatments including con-trol(CK,no urea applied),one-time base application of nitrogen fertilizer(S1,urea+DCD),two-time application of nitro-gen fertilizer(S2,urea applied at 40%base,60%urea applied at large trumpet stage)and three-time application of nitro-gen fertilizer(S3,urea applied at 20%base,40%urea was applied in the small trumpet stage,40%urea was applied in the tasseling stage).The N2O gas was collected at the 2nd,5th and 8th d after fertilization,and collected once each week later to determine the soil N2O emission flux and cumulative emission,soil samples were collected before fertilization and during gas extraction to determine soil pH and other chemical properties,plant biomass,yield and nitrogen use efficiency were determined during maize harvesting.[Result]There was no significant difference between soil pH of nitrogen application treatment and CK(P>0.05,the same below),but soil pH of S1 treatment was the lowest and significantly lower than that of S2 treatment(P<0.05,the same below).Compared with S2 and S3 treatments,S1 treatment significantly reduced soil total nitrogen content by 6.15%and 12.86%respectively.S1 treatment was beneficial to increase soil available P content,but not conducive to the accumulation of available potassium,S2 and S3 treatment has no significant effect on soil availa-ble phosphorus and available potassium content.Nitrogen application significantly increased maize plant biomass and yield,both values in S1 treatment were the highest.Compared with S2 and S3 treatments,S1 treatment significantly in-creased maize plant biomass by 30.42%and 10.95%,and yield significantly increased by 13.37%and 19.05%respec-tively.The nitrogen efficiency of S1 treatment was the highest,which was significantly increased by 37.00%and 59.38%compared with S2 and S3 treatment respectively.Nitrogen application significantly increased nitrogen content in maize or-gans.The cumulative nitrogen uptake of maize plants under S1 treatment was 22.95%and 34.69%higher than that under S2 and S3 treatment respectively.S1 and S3 treatments were beneficial for nitrogen distribution to stems and leaves,but S2 treatments did not change the way of nitrogen distribution.Nitrogen application promoted N2O emission,and the cumu-lative N2O emission of all nitrogen application treatments was significantly higher than that of CK,and the highest N2O emission was found in S2 treatment,which decreased by 54.46%and 54.33%in S1 and S3 treatments respectively,com-pared with S2 treatment.The HN4+-N content of soil in each treatment had an obvious peak from the trumpet stage to the harvest stage,while the peak time of NO3--N content in soil was different.Correlation analysis results showed that N2O emission flux was extremely significantly and positively correlated with NO3--N content and soil water content(P<0.01,the same below),and extremely significantly and negatively correlated with 5 cm soil temperature.[Conclusion]Com-pared with multiple nitrogen application,nitrogen fertilizer combined with nitrification inhibitor one-time base application can significantly promote the fresh maize growth,yield,nitrogen efficiency and also reduce N2O emission at the same time.It can be used as the recommended fertilization mode for fresh maize in Hainan.
fresh maizenitrogen fertilizernitrification inhibitormaize yieldnitrogen use efficiencyN2O emi-ssion
万方数据
维普
