A method and system for determining the nitrogen content of tree leaves in the period of fruit expansion

Abstract

The invention relates to a method for determining the nitrogen content of tree leaves in the fruit expansion stage, comprising: performing spectral sampling on leaf samples to obtain four groups of sensitive band spectral values; obtaining the nitrogen content of leaf samples; The first differential vegetation index is calculated from the sensitive band spectral values; the second differential vegetation index is calculated according to the sensitive band spectral values ​​of the third group and the fourth group, and the initial four vegetation indices are calculated according to the first differential vegetation index and the second differential vegetation index. Band hyperspectral index; draw an initial regression curve according to the initial four-band hyperspectral index and nitrogen content; determine the optimal four-band hyperspectral index according to the initial regression curve; establish an optimal monitoring model based on the optimal four-band hyperspectral index and nitrogen content; The leaf nitrogen content in the test samples was calculated according to the optimal monitoring model. The invention uses fewer bands, has a simple and convenient calculation method, and can improve the accuracy, simplicity and high efficiency of determining the nitrogen content of tree leaves in the fruit expansion stage.

Description

technical field [0001] The invention relates to the technical field of agricultural vegetation remote sensing, in particular to a method and system for determining the nitrogen content of tree leaves in the fruit expansion stage. Background technique [0002] Among the various phenological periods of the annual growth and development of fruit trees, the fruit expansion period is the dividing point between vegetative growth and reproductive growth of the tree, which marks the transition from vegetative growth to reproductive growth of fruit trees. Since this period is an important period for the formation of fruit tree yield and quality, the quality of its production management can directly affect the economic income of fruit farmers in that year. Therefore, in terms of production, in order to increase the yield, farmers often blindly and excessively apply nitrogen fertilizer (commonly known as "fruit-enhancing fertilizer") during the fruit expansion period in order to obtain...

AI Technical Summary

Problems solved by technology

However, the four-band hyperspectral index estimation model for leaf nitrogen content in the fruit expansion period has not been reported, and at the same time, the accurate, simple and efficient estimation of the tree leaf nitrogen content in the fruit expansion period cannot be achieved in the existing technology

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