Method and system for determining nitrogen content of tree leaves in fruit expansion period

Abstract

The invention relates to a method for determining the nitrogen content of tree leaves in a fruit expansion period. The method comprises the following steps: carrying out spectral sampling on a leaf sample to obtain four groups of sensitive waveband spectral values; acquiring the nitrogen content of a leaf sample; calculating a first difference vegetation index according to a first group and a second group of the sensitive waveband spectral values; calculating a second difference vegetation index according to a third group and a fourth group of the sensitive waveband spectral values, and calculating an initial four-waveband hyperspectral index according to the first difference vegetation index and the second difference vegetation index; drawing an initial regression curve according to the initial four-waveband hyperspectral index and the nitrogen content; determining an optimal four-waveband hyperspectral index according to the initial regression curve; establishing an optimal monitoring model according to the optimal four-waveband hyperspectral index and the nitrogen content; and calculating the nitrogen content of the leaves in a detected sample according to the optimal monitoringmodel. According to the method, the number of used bands is small, a calculation method is simple and convenient, and the accuracy, convenience and high efficiency of determining the nitrogen contentof tree leaves in the fruit expanding period can be improved.

Description

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

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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