SHADOW EFFECT ON MULTI-SPECTRAL IMAGE FOR DETECTION OF NITORGEN DEFICIENCY IN CORN

摘要

Recently to determine the site-specific yield potential, multi-spectral image analysis including aerial image and ground-based image have been used. The efficiency of side-dressing, a more efficient of nitrogen application method than uniform application in either late Fall or early Spring, is relies heavily on the capability of nitrogen deficiency detection on a sprayer. In this study the SPAD value was used as a reference data. This sensor assesses nitrogen level of the corn based on the corn leave reflectance sensed using three channels (green, red, near-infrared) of a multi-spectral camera. Some acceptable calibration relationships between the multi-spectral reflectance and SPAD readings have been found from previous study. The core of this investigation was the shadow effect on image, on sunny weather condition there was a shadow made by corn leave itself. By analyzing this shadow effect on the image the efficiency of multi-spectral nitrogen deficiency sensor was improved.