Nitrogen use efficiency and nitrogen changes in soil profile under long-term synergistic use of organic and inorganic exogenous N
Effects of synergistic use of organic and inorganic exogenous nitrogen on the yield of winter wheat and maize and nitrogen changes in soil profile can provide a theoretical basis for rationally reducing the application rate of nitrogen fertilizers and increasing their utilization rate,and scientifically managing soil nitrogen resources.A 28 year in situ fertilization experiment was used.Four fertilization treatments were investigated:no nitrogen fertilizer(CK),chemical fertilizer only(CF),chemical fertilizer plus organic manure(CFM)and chemical fertilizer plus maize straw(CFS).The effects of long-term combined use of chemical nitrogen,organic manure,and straw as major exogenous nitrogen on sustainable production capacity,nitrogen fertilizer use efficiency,fertilizer after-effect,nitrogen changes in soil profile were analyzed.The results showed that long-term combined use of chemical nitrogen,organic or straw fertilizer increased crop yield,compared with CK treatment,the yields of winter wheat under CF,CFM and CFS treatments increased by 280.49％,276.02％and 286.73％,the yields were increased by 160.15％,170.86％and 178.45％,respectively.Compared with CK,the yield coefficient variation of CF,CFM and CFS treatment increased in wheat and maize seasons,and the increase of wheat season was larger.The yield sustainability index of CFS treatment in wheat season was the highest(66.32％),while the yield sustainability index of CFM and CFS treatment in maize season was basically the same,higher than that of CF treatment.Compared with CF treatment,the average nitrogen absorption of CFM and CFS was increased by 2.11％and 4.29％,respectively.The accumulated nitrogen fertilizer use efficiency of CF,CFM and CFS treatments were 61.12％,62.91％and 64.78％,respectively.The average after-effects of CF,CFM and CFS treatments were 0.72％,0.90％and 0.60％,respectively,application of chemical fertilizer plus organic manure alone had the highest after-effect.Compared to CF,CFM treatment increased total nitrogen content in 0-40 cm soil layer by 22.08％-35.94％,soil available N content in 0-40 cm soil layer by 12.05％-38.17％.In conclusion,the input of exogenous nitrogen maintained the best sustainable production capacity and the annual nitrogen fertilizer use efficiency in the wheat-maize rotation system.Straw and organic fertilizer application together enhanced the soil total nitrogen.
exogenous nitrogenyieldannual nitrogen fertilizer use efficiencyaccumulated nitrogen fertilizer use efficiencynitrogen distribution in soil profile
万方数据
维普
