【作者】 张生飞；

【导师】 罗卫红；

【作者基本信息】 南京农业大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 黄瓜为国内外温室栽培的主要蔬菜作物之一,氮素是影响作物干物质生产、分配和产量形成的重要营养元素。为定量研究不同定植期温室无土栽培黄瓜对氮素的需求,本研究以雌性无限生长型品种‘戴多星’（Cucumis Sativus.‘Deltastar’）为试验材料,于2005-2006年在上海孙桥现代化农业园区的PVC联栋温室内进行了不同定植期和不同氮素水平的试验。以冠层辐热积为尺度,确定了不同光温条件下黄瓜叶片的适宜含氮量,在此基础上建立了温室黄瓜无土栽培营养液氮素管理模型,并对模型进行了应用案例分析。结果表明,模型推荐的营养液氮素浓度在获得高产的同时还能提高氮素利用率,可以应用于温室无土栽培黄瓜养液氮素的精确管理。（1）温室黄瓜无土栽培营养液氮素管理模型。定量分析了不同定植期黄瓜叶片含氮量随生育期的变化规律,以及叶片含氮量与叶片净光合作用速率和产量的定量关系,确定了不同光温条件下黄瓜叶片适宜含氮量的求算方法,以及盛果期黄瓜叶片含氮量与营养液氮素浓度的关系。在此基础上,建立了温室黄瓜无土栽培营养液氮素管理模型。结果表明,盛果期的叶片含氮量可以作为温室黄瓜氮素管理指标,黄瓜叶片净光合作用速率和产量随盛果期叶片含氮量升高按负指数规律增加。通常情况下,春夏茬无土栽培黄瓜盛果期叶片含氮量不能低于3.2%,秋冬茬不能低于3.5%。营养液氮浓度春夏茬一般不能低于90 mg·L^-1,秋冬茬不能低于65 mg·L^-1。（2）模型应用案例分析。以模型推荐(80 mg·L^-1)、常规水平(160 mg·L^-1)和较低水平(40 mg·L^-1)三个施氮水平试验作为案例,通过分析对比三个不同施氮水平黄瓜叶片净光合作用速率、地上部生物量、产量和氮素利用率的差异,以此对氮素管理模型进行检验。结果表明,氮素管理模型推荐的营养液浓度处理和常规氮素浓度处理在叶片净光合作用速率、地上部生物量及产量指标上均无显著差异,但模型推荐氮素处理的氮素利用率比常规处理的氮素利用率提高了18.9%。本研究建立的模型推荐的氮素浓度在获得高产的同时还能提高氮素利用率,有效减少了肥料的浪费和环境污染,可以为温室无土栽培黄瓜氮肥优化管理提供理论依据和决策支持。更多还原

【Abstract】 Cucumber is one of the most popular crops cultivated in greenhouse in the world. Nitrogen is the important nutrient affecting dry matter production,partitioning and yield formation of plants.The aim of this study is to quantitatively investigate the demand of nitrogen（N） of greenhouse cucumber.Experiments with different planting dates and levels of nitrogen application rate after anthesis for greenhouse fruit cucumber（Cucumis Sativus.’Deltastar’） were conducted in a multi-span PVC greenhouse in Shanghai during 2005～2006.The integrated photo-thermal index,the average product of thermal effectiveness and PAR above canopy（ATEP）,was used to describe the optimal leaf nitrogen concentration of greenhouse cucumber under different radiation and temperature conditions.Based on these quantitative relationships,a management model of nitrogen concentration of the nutrient solution was developed.Another experiment was held in order to test and validate the model for management of nitrogen concentration in the nutrient solution for soilless cultivated cucumber crops in greenhouse.The results show that the nitrogen concentration suggested by the model results in higher nitrogen use efficiency while keeping the yield as high as the conventional nitrogen concentration. Therefore,the model developed in this study can be used for precision management of nitrogen for greenhouse cucumber crop production.（1） The model for management of nitrogen concentration in the nutrient solution for soilless cultivated cucumber crops in greenhouse.The seasonal time course of leaf nitrogen concentration and its relation to the leaf net photosynthesis rate and yield were analyzed. Then,the optimal leaf nitrogen concentration for soilless cultivated cucumber crop in greenhouse in different seasons was determined.Leaf net photosynthesis rate and yield of cucumber were found to be increased exponentially with the leaf nitrogen concentration at the middle fruit harvest stage.The relationship between the leaf nitrogen concentration at the middle fruit harvest stage and the nitrogen concentration of the nutrient solution was then quantified.Based on these quantitative relationships,a management model of nitrogen concentration of the nutrient solution was developed.The results show that the leaf nitrogen concentration at the middle fruit harvest stage was used as an index for nitrogen management for cucumber crop in greenhouse.The leaf nitrogen concentration at middle fruit harvest stage should higher than 3.2%,3.5%,respectively,for the Spring-Summer season and the Autumn-Winter season and the corresponding nitrogen concentration of the nutrient solution were at least 90 mg·L^-1 and 65 mg·L^-1 respectively.（2） Test and validate the model.Experiments with three levels(model suggested level 160 mg·L^-1,conventional level 80 mg·L^-1 and low nitrogen level 40 mg·L^-1) of nitrogen application rate were conducted in a greenhouse in Shanghai during 2006.The seasonal time course of leaf net photosynthesis rate,shoot biomass,yield and nitrogen use efficiency of the cucumber crops with the three levels of nitrogen application rate were analyzed.The results show that the cucumber crops with nitrogen application rate of model suggested level(80 mg·L^-1) and that of conventional level(160 mg·L^-1) did not have significant differences in leaf net photosynthesis rate,shoot biomass production and yield.The nitrogen use efficiency of the cucumber crop with nitrogen application rate of model suggested level was 18.9%higher than that of conventional level.The nitrogen concentration suggested by the model results in higher nitrogen use efficiency while keeping the yield as high as the conventional nitrogen concentration.The model reduce the waste of nitrogen and protect the environment,hence,can be used for optimization nitrogen management for greenhouse fruit cucumber production.更多还原