温室网纹甜瓜临界氮浓度和氮营养指数模拟研究

Simulation of critical nitrogen concentration,nitrogen uptake and nitrogen nutrition index of greenhouse muskmelon

为实现精准的氮营养诊断和指导生产,研究通过4个不同氮素水平处理的温室网纹甜瓜基质栽培试验,构建了临界氮浓度稀释曲线模型,并推导得到了氮素吸收和氮营养指数模型。结果表明:临界氮浓度稀释曲线模型(%N c=4.235DW-0.353 max)揭示了植株地上部生物量和氮浓度值之间呈幂函数关系,决定系数R 2=0.814,同时得到最高和最低氮浓度稀释曲线,决定系数分别为R 2=0.808、R 2=0.810;氮素吸收模型和氮营养指数模型对网纹甜瓜营养诊断结果基本一致,植株适宜的氮素施用量为始瓜期前4.1 g/株,之后1.3~2.7 g/株。本研究提出的临界氮浓度、氮素吸收和氮营养指数模型,相较于传统的经验方法更具有机理性,可为温室网纹甜瓜的氮肥管理决策提供理论依据。

In order to achieve accurate nitrogen nutrition diagnosis and guide production,this study constructed a critical nitrogen concentration dilution curve model of greenhouse muskmelon,through the crop aggregate cultivation experiments with four different levels of nitrogen treatments.Then nitrogen uptake model and nitrogen nutrition index model were derived.The results showed that there is a power function relationship between plant’s aboveground biomass and nitrogen concentration(%N c=4.235DW-0.353 max,R 2=0.814).The highest and lowest nitrogen concentration dilution curves were obtained as well,and the coefficients of determination were 0.808 and 0.810,respectively.The nutrition diagnosis result of nitrogen uptake model constructed was consistent with the result of nitrogen nutrition index model.The optimum applications of nitrogen before and after the beginning melon stage were 4.1 g and 1.3-2.7 g per plant,respectively.The models proposed in this study were better than traditional empirical methods,and could provide a theoretical basis for the appropriate management of nitrogen fertilizer application in greenhouse muskmelon production.