Rapid nondestructive high-accuracy method with for identifying abundance degree of nitrogen element in plant leaf

The invention discloses a high-spectrum-based rapid nondestructive high-accuracy method for identifying the abundance degree of a nitrogen element in a plant leaf. The method comprises the following steps: performing high-spectral collection on a leaf sample; performing noise-reduced preprocessing on high-spectral data and then performing characteristic extraction on the spectral data; establishing a correction model of the spectrum characteristic and the category of the level standard of the nitrogen element in the plant leaf; collecting high-spectral data of an unknown sample; performing the noise-reduced preprocessing on the spectral data of the unknown sample and then converting a spectrum of the unknown sample to form a characteristic space; substituting the correction model into the characteristic space so as to perform identifying on the level category of the nitrogen element, so as to obtain whether the plant leaf is in nitrogen deficiency or contains the nitrogen element with the normal/excessive amount. According to the technical scheme, a portable high-spectral instrument is utilized to collect the spectrum of the plant leaf; an Adaboost+SLPP characteristic extraction method is utilized to perform the characteristic extraction on the spectral data of the plant leaf; and a KNN (K-Nearest Neighbor) serves as a categorizer, so that the identification predicting accuracy is improved effectively.