In order to determine distribution of ambrosia within soybean at different fertilization rates on experimental field Potok–Popovača (2005), technique of aerial digital imaging at ground level by digital RGB camera was applied. The digital imaging was carried out within multidiscipline research team: Faculty of Agriculture, Faculty of Geodesy and Croatian Centre for Demining. Area of cca. 4 ha (300x130m), was under long time research with 10 different rates of nitrogen fertilization. Based on interpretation of aerial digital imagery, the main object of this study was to determine ambrosia weediness in soybean at different rates of nitrogen fertilization, its spatial distribution within soybean, and nitrogen taking by ambrosia and soybean. Ambrosia detection from aerial digital RGB imagery and its spatial distribution have been defined. Bases to continue research by airborne multispectral digital imaging of experimental field within different crops during following years were provided. Digital imaging of field variants at diff erent fertilization rates, and ground samples (4 by experimental variant), including land surveying, was performed by digital RGB camera from 13th - 25th September, 2005. Interpretation of aerial digital imagery was made by field data analysis obtained by sampling plant material, in order to determine biomass, moisture and nitrogen content in both species. Comparison with field data shows that method of aerial digital RGB imagery interpretation is reliable mean of weed detection within immanent crop, and its spatial distribution at different fertilization rates – ambrosia distribution/variant.

ambrosia; soybean; digital imagery; RGB spectrum; image classification; spatial distribution; biomass; nitrogen fertilization

Published by University of Zagreb, Faculty of Agriculture, Zagreb, CROATIA
Sponsored by Ministry Science and Education of the Republic of Croatia