有机肥与氮肥配施对日光温室黄瓜和土壤硝酸盐含量的影响

在保护地栽培条件下,采用裂区设计,研究不同有机肥用量和氮肥用量配施对黄瓜NO3--N含量、不同层次土壤NO3--N含量动态变化的影响。结果表明:增施氮肥显著提升黄瓜果实NO3--N含量,氮肥与有机肥配合能够降低黄瓜NO3--N含量,交互作用极显著。高有机肥用量与高氮肥用量施用及施用氮肥不配合有机肥,保护地黄瓜NO3--N含量达到二级污染程度。黄瓜NO3--N含量、土体NO3--N的供应水平和积累量与有机肥、氮肥的施用密切相关,高量施用有机肥上层土壤NO3--N易积累,高氮肥用量(N3)处理易使土体积累NO3--N,施用有机肥能够减弱土壤中NO3--N的淋失。生产中降低黄瓜NO3--N含量和土体NO3--N淋失、积累量的施肥措施是:施用有机肥量为45~90 thm-2,施用纯氮水平为450~750 kghm-2。

Effect of Co-application of Organic and Nitrogen Fertilizer on Nitrate Content of Cucumber and Soil in Greenhouse

A spilt-plot design was used to study the effect of co-application of organic and nitrogen fertilizer on nitrate content of cucumber and the dynamic change of that in different layers of soil under the condition of protected cultivation.The result indicated that the nitrate content of cucumber was increased remarkably by increasing the rate of nitrogen fertilizer.But that could decrease when applying the organic fertilizer and nitrogen fertilizer together,and the interaction of these two fertilizers was extremely significant.The nitrate content of greenhouse cucumber reached the degree of secondary pollution when high amount of organic fertilizer and nitrogen fertilizer was applied in singles,as well as the normal application of nitrogen without organic fertilizer. The nitrate content of cucumber and the capability of supplying nitrate in soil and its accumulation amount in soil body had a closely relativity with the organic fertilizer and nitrogen application.The top soil could accumulate nitrate easily by organic fertilizer application in high amount,so did the soil body by applying nitrogen fertilizer in the same way(N3).However,the leach of soil nitrate could be weaken by organic fertilizer application.So the measure was to apply organic fertilizer 45 ~ 90tohm-2,and nitrogen application was done with the level 450 ~ 750kgohm-2 in agricultural practices,which could reduce the nitrate content of cucumber and weaken the leach of it and decrease its accumulation amount in soil body.