有机肥不同比例替代化肥氮对水稻产量、氮素吸收与流失风险的影响

Effects of Different Ratios of Inorganic-N Substituted by Manure on Rice Yield,Nitrogen Absorption and Nitrogen Loss Risk

有机肥与化肥配施是农业生产中稳产增产、减少化肥施用和保护环境的重要生产模式。为探索有机肥替代化肥氮的合理比例,采用田间小区试验,设置6个有机肥替代化肥氮的比例梯度(0%、10%、20%、30%、40%和50%),分析了有机肥替代化肥氮的比例差异对水稻产量、氮素利用率和氮流失风险的影响。结果表明:与常规化肥处理比较,20%的替代比对早稻的有效穗数显著增加了5.8%,对晚稻的产量构成因素(穗长增加16.1%、有效穗数增加7.4%、实粒数增加11.8%、千粒重增加11.1%、结实率增加4.5%)均有显著的增加效果,且早、晚稻分别显著增产13.9%和18.6%,氮肥吸收利用率分别显著增加4.7%和4.9%。替代比例与早、晚稻产量的拟合方程得出产量最佳的替代比均为21%。有机肥氮配施比例越大,田面水氮浓度越低,减少了氮素径流损失风险。因此,有机肥替代化肥氮的比例20%时,既可以提高水稻增产潜力,又能降低稻田氮素流失风险和适当减少稻田化学氮肥施用量,值得推广应用。

The combination of organic and inorganic fertilizer is an important agricultural mode for increasing crop production,reducing the application of chemical fertilizer and protecting environment.In order to explore the optimal ratio of organic fertilizer-N instead of chemical fertilizer-N,a field plot experiment was conducted to study the effects of different ratios of organic fertilizer-N replacing chemical fertilizer-N on rice yield,nitrogen utilization and nitrogen loss risk,and six consecutive alternative proportional gradients(0%,10%,20%,30%,40%,50%)were set in this paper.The results showed that:Compared with common urea treatment,a 20%substitution ratio of organic fertilizer-N significantly increased the effective panicle number of early-rice by 5.8%,and significantly increased the yield components of late-rice(i.e.panicle length increased by 16.1%,effective panicle number increased by 7.4%,grain number increased by 11.8%,1000-grain weight increased by 11.1%,seed setting rate increased by 4.5%).And a 20%substitution ratio treated early-and late-rice significantly increased yield by 13.9%and 18.6%,respectively,while simultaneously significantly increased nitrogen fertilizer utilization rate by 4.7%and 4.9%respectively.The fitting equation between substitution ratio and yield of early-and late-rice showed that the best substitution ratio of yield was 21%.The greater the ratio of organic fertilizer nitrogen application,the lower the water and nitrogen concentration in the field,reducing the risk of nitrogen loss.Therefore,it could not only increase rice yield potential,but also reduce the risk of nitrogen loss in paddy fields and appropriately reduce the amount of chemical nitrogen fertilizer applied in paddy fields when the ratio of organic fertilizer to fertilizer nitrogen was 20%in early-and late-rice cropping system.It was worthy of popularization and application.