Apple tree canopy scale nitrogen content diagnosis method

Abstract

The invention discloses an apple tree canopy scale nitrogen content diagnosis method. The method comprises the following steps: determining the reflectivity of an apple tree canopy scale by adopting ahyper-spectrometer; selecting an apple tree canopy leaf sample; determining the total nitrogen content of the apple tree canopy leaf sample; identifying abnormal samples in a reflectivity data set and a total nitrogen content data set by utilizing a Monte Carlo secondary detection method; preprocessing the reflectivity data set; aiming at the obtained reflectivity data sets of 1326 wave bands, extracting variables based on a potential variable method in a partial least squares regression analysis process; establishing a model for the extracted variables by adopting an extreme learning machine; and predicting the nitrogen content of the apple tree canopy leaves by utilizing the established model. According to the method, canopy scale spectral information is collected for nitrogen conditiondiagnosis, errors caused by sample randomness due to existing leaf scale diagnosis are effectively avoided, and the diagnosis result can measure the overall canopy nitrogen condition of the apple tree.

Description

technical field [0001] The invention belongs to the technical field of apple cultivation, and more specifically relates to a method for diagnosing nitrogen content at the canopy level of apple trees. Background technique [0002] my country is the country with the largest apple planting area, accounting for 45% and 49% of the world's planting area and fresh fruit production respectively. The input of nitrogen fertilizer is closely related to the yield and quality of apples, and the high economic benefits of apples also lead growers to invest a lot of nitrogen fertilizer. The nitrogen fertilizer input in apple orchards in my country is 726-1720kg / ha, with an average of 1220kg / ha. However, the blind input of nitrogen fertilizer makes the utilization rate of nitrogen fertilizer low, and a large part of mineral nitrogen enters the subsoil, which is difficult to be used by fruit trees. [0003] At present, the laboratory chemical analysis method is mainly used to detect plant ni...

AI Technical Summary

Problems solved by technology

The input of nitrogen fertilizer is closely related to the yield and quality of apples, and the high economic benefits of apples also lead growers to invest a lot of nitrogen fertilizer

The input of nitrogen fertilizer in apple orchards in my country is 726-1720kg / ha, with an average of 1220kg / ha. However, the blind input of nitrogen fertilizer makes the utilization rate of nitrogen fertilizer low, and a large part of mineral nitrogen enters the lower soil, which is difficult to be used by fruit trees.

[0003] At present, the laboratory chemical analysis method is mainly used to detect the nitrogen content of plants. This method has high accuracy, but requires local destructive sampling and has low timeliness.

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