Chinese Journal of Agrometeorology ›› 2019, Vol. 40 ›› Issue (08): 523-533.doi: 10.3969/j.issn.1000-6362.2019.08.005

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Establishment of a Critical Nitrogen Dilution Model for Grapes and Nitrogen Nutrition Diagnosis under Different Water Conditions

LI Jia-shuai, YANG Zai-qiang, LI Yong-xiu, JIANG Meng-yuan, ZHAO He-li, WEI Ting-ting, ZHANG Xu-ran   

  1. 1.Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing 210044, China; 2.Jiangsu Provincial Key Laboratory of Agrometeorology, Nanjing 210044
  • Online:2019-08-20 Published:2019-08-01

Abstract:

In this paper, a two-factor pot experiment was carried out in the Venlo-type greenhouse, using the annual grape of "Hongti" variety as experimental material. There were four irrigation levels and four nitrogen application levels in the two-factor pot experiment. Four irrigation levels were normal irrigation (W1, 70%-80% of the maximum water holding capacity in the field), slight drought stress (W2, 60%-70%), moderate drought stress (W3, 50%-60%) and extra severe drought tress (W4, 30%-40%). And four nitrogen application levels were 1.5 times normal recommended nitrogen application rate(N1, 25.5gplant-1), normal recommended nitrogen application rate(N2, 17gplant-1), 0.5 times normal recommended nitrogen application rate(N3, 8.5gplant-1) and no nitrogen application(N4, 0gplant-1). The nitrogen concentration in the plant and the aboveground biomass of the plant were observed every 10 days. The minimum nitrogen concentration corresponding to the maximum biomass obtained by grape plants under different water conditions in a certain period is called Nitrogen critical concentration (Nc), it can be used to construct the model of nitrogen critical concentration dilution curve of grape, which can further establish Nitrogen uptake model (Nupt) and Nitrogen Nutrition Index model (NNI) for quantitative diagnosis of nitrogen nutrition status of grapes under different water conditions.The results showed: there was a power function relationship between the nitrogen critical concentration and aboveground biomass of grape plants, which embodied as the nitrogen critical concentration, nitrogen uptake and aboveground biomass of grape plants all increased as the irrigation amount increasing. As nitrogen application increased, the biomass of grape plants under treatments of W1 and W2 increased, while that under W3 and W4, increased first and then decreased. Under the same water condition, the nitrogen concentration increased with the increase of nitrogen application and decreased with the progress of grapes growth. The established Nupt and NNI models can be used to effectively diagnose the deficiency of nitrogen nutrients in plants.

Key words: Grape, Nitrogen critical concentration, Nitrogen nutrition index, Nitrogen uptake, Dry matter accumulation