Journal article
Evaluation of an online approach for determination of percentage residue cover

Publication Details
Pforte, F.; Wilhelm, B.; Hensel, O.
Publication year:
Biosystems Engineering
Pages range:
Volume number:

An online sensor for measuring residue cover with the help of fast image analysis offers new advantages. A prototype of such a sensor system was tested, though its quality of work under real world conditions can only be specified relative to other methods acting as a reference. Therefore, a combination of different tests was conducted. In field trials with defined surface residue densities (kg ha(-1)) the readings of the camera sensor, a visual standard method (grid) and visual estimations were correlated with each other and with the quantities of surface straw and tillage depth. Correlation coefficients between the methods of 0.7-0.9 were found. The methods were also checked against the results of manually controlled classification of images taken at 70 selected geo-referenced reading points. This yielded the best result for the camera sensor with a correlation coefficient of 0.962. Additionally, in a laboratory test with well-defined artificial cover rates, the characteristic behaviour of image analysis and the grid method was investigated. A slight overrating of the cover by the grid method and a small error caused by the camera lens aberration could be identified. The suitability in principle of online image processing as a new reference method has been demonstrated. However, in the field, the camera sensor provided the greatest reliability, compared to untrained human observers at cover rates below about 50%. At higher residue covers, human perception might have some advantage. (c) 2012 IAgrE. Published by Elsevier Ltd. All rights reserved.

Last updated on 2020-17-08 at 10:36