Precision harrowing using a bispectral camera and a flexible tine harrow
In the given study an adjustable harrowing system is presented and tested. The automatic harrow can increase or decrease the harrowing intensity during operation. A gentle (20%), medium (40%) and aggressive (60%) harrow intensity was chosen. Prior to the application, measurements were performed in each plot concerning the weed density and composition. With this information, a Decision Support System based on fuzzy logic was used in order to trigger an appropriate tine angle movement. Thus, areas with high crop and weed densities were applied with more aggressive harrowing treatments and areas with lower weed densities with a gentler treatment. A spring barley field was adopted to evaluate the suitability and effectiveness of the system at the University of Hohenheim, Germany. A harrow application was conducted at the maximum permitted harrow intensity (60%), as the farmer would have applied it on the field and an automatic adaptation, based on the results of the decision support system. A further herbicide treatment and an untreated control were also included. Weed counting was performed prior to and after the application, along with biomass cuts and yield in order to estimate the treatment efficacy. The automatic system performed well, providing similar results as the nonautomatic harrowing, but with lower intensity levels. Dicotyledonous weeds were, in both mechanical applications, reduced as well as by the herbicide application, without any significant differences.