氮肥和有机肥配施对盐碱地酿酒高粱生长、氮素利用效率及土壤N_(2)O排放的影响

Effects of combined application of nitrogen fertilizer and organic fertilizer on the growth,nitrogen use efficiency of brewing sorghum and soil N_(2)O emission in saline-alkali land

采用田间小区试验,依照等氮替换原则,设不施氮肥处理,优化氮肥施用量180 kg·hm^(-2)单施化肥、40%有机肥替代化肥、60%有机肥替代化肥,常规氮肥施用量240 kg·hm^(-2)单施化肥、40%有机肥替代化肥、60%有机肥替代化肥共7个处理,探究河套灌区盐渍土氮肥与有机肥配施对酿酒高粱生长特性、氮素利用效率及土壤N_(2)O排放的影响。结果表明:(1)相同施氮量下,60%有机肥替代化肥处理成熟期土壤全氮、碱解氮和有机质含量较单施化肥处理分别增加10.52%~12.77%、36.36%~50.64%、41.58%~51.33%。(2)相同施氮量下,40%有机肥替代化肥处理高粱产量均高于其他施肥处理,增产6.63%~15.72%。(3)施氮量180 kg·hm^(-2)40%有机替代处理较其他施肥处理氮肥利用率提高1.98%~22.84%,氮肥偏生产力提高3.49~17.19 kg·kg-1;施氮量240 kg·hm^(-2)40%有机替代处理较其他施肥处理氮肥农学利用率提高0.48~6.11 kg·kg^(-1)。(4)相同施氮量下,60%有机替代处理农田N_(2)O排放量最小,较单施化肥处理和40%有机替代处理分别减少41.50%~47.97%、3.82%~11.52%;40%有机替代处理次之。综合酿酒高粱产量、生长状况、氮素利用率及土壤N_(2)O气体排放的变化情况,氮肥施用量180 kg·hm^(-2)下有机肥替代40%化肥是河套灌区酿酒高粱种植较为适宜的氮肥用量及有机配比。

According to the principle of equal nitrogen replacement,a field plot experiment including 7 treatments of a non-nitrogen fertilizer treatment,optimize the nitrogen fertilizer application rate of 180 kg·hm^(-2)single fertilizer,40%organic fertilizer replacement fertilizer,60%organic fertilizer replacement fertilizer,conventional nitrogen fertilizer application rate of 240 kg·hm^(-2)single fertilizer,40%organic fertilizer replacement fertilizer,and 60%organic fertilizer replacement fertilizer was conducted to examine the effects of nitrogen fertilizer and organic fertilizer on the growth characteristics,nitrogen utilization efficiency and N_(2)O emission of wine sorghum in saline soil of Hetao irrigation area.The results showed that:(1)under the same nitrogen application rate,the content of total nitrogen,alkali-hydrolyzable nitrogen and organic matter in mature soil treated with 60% organic fertilizer instead of chemical fertilizer increased by 10.52%~12.77%,36.36%~50.64%and 41.58%~51.33%,respectively,compared with that of treatment with chemical fertilizer alone.(2)Under the same nitrogen application rate,the sorghum yield of 40%organic fertilizer instead of chemical fertilizer treatment was higher than that of other fertilizer treatments,with an increase of 6.63%~15.72%.(3)Compared with other fertilization treatments,the nitrogen fertilizer utilization rate of 180 kg·hm^(-2)40%organic substitution treatment increased by 1.98%~22.84%,and the partial productivity of nitrogen fertilizer increased by 3.49~17.19 kg·kg^(-1).The agronomic utilization rate of nitrogen fertilizer in 40%organic substitution treatment with 240 kg·hm^(-2)nitrogen application rate was 0.48~6.11 kg·kg^(-1) higher than that in other fertilization treatments.(4)Under the same nitrogen application rate,the N_(2)O emission of 60% organic substitution treatment was the smallest,which decreased by 41.50%~47.97% and 3.82%~11.52%respectively compared with the treatment of chemical fertilizer alone and 40%organic substitution treatment;40%organic substitution treatment takes the second place.Based on the yield,growth status,nitrogen utilization rate and N_(2)O emission of brewing sorghum,the replacement of 40%chemical fertilizer with organic fertilizer at 180 kg·hm^(-2)nitrogen fertilizer application rate was the more suitable nitrogen fertilizer application rate and organic ratio for brewing sorghum cultivation in the Hetao irrigation area.