设施栽培黄瓜临界氮浓度和氮营养指数模拟

以黄瓜津春5号为试验材料,采用随机区组设计,2016和2017年分别设置了5个氮浓度梯度,构建了黄瓜地上部生物量的临界氮浓度稀释模型,在此基础上建立了氮素吸收模型和氮营养指数模型。结果表明,黄瓜地上部临界氮浓度与地上部最大生物量之间符合幂指数关系,%Nc=4. 539 7x-0. 06,相关系数为R2=0. 749 6。基于临界氮浓度建立的设施栽培黄瓜氮素吸收(Nupt)模型、氮素营养指数(NNI)模型,可作为设施栽培黄瓜氮素营养状况的判别指标,本试验条件下295. 7～305. 5 kg/hm~2为黄瓜最佳施氮量。

Simulation of critical nitrogen concentration and nitrogen nutrition index in greenhouse cucumber

In this study,the cucumber Jinchun 5 was used as experimental material and the experiment adopted randomized block design.Five nitrogen concentration gradients were set up in 2016 and 2017,respectively,and a critical nitrogen concentration dilution model of aboveground biomass of cucumber was constructed.Based on this model,nitrogen absorption model and nitrogen nutrition index model were constructed,and the suitable appropriate nitrogen application rate was calculated for the cucumbers in the greenhouse.The results showed that the relationship between the critical nitrogen concentration and the maximum biomass in the upper ground of cucumber was in a power exponent relationship with %Nc=4.539 7x-0.06,and the correlation coefficient was R2=0.749 6.The critical nitrogen concentration was established based on the model of greenhouse cucumber nitrogen uptake(Nupt),nitrogen nutrition index(NNI) model,which can be used to determine the index of nitrogen nutrition of greenhouse cucumber under the conditions of this study,the test results show that the 295.7~305.5 kg/hm2 is the best appropriate of nitrogen fertilizer of cucumber.