A virtual spreader to overcome experimental limits: Example of use to deepen the meaning of the transverse coefficient of variation
International audience; A virtual spreader was modelled by combining the use of theoretical motion equations and statistical distributions of input parameters. These parameters were deduced from experimental measurements using a custom-made spreader, an imaging system, a particle impact recording device and a rotating test bench. Using this model, each spread pattern was computed using a random selection of values following the statistical distribution of each input parameter. Using simulations, we quantified how the CV value was affected by application rates and measurement protocols whatever spreader settings. Simulations showed the CV value and its measurement variability increased when …
Herbicide site specific spraying: use of simulations to study the impact of section width
International audience; Site specific spraying is one way to reduce the amount of herbicide required to control weeds. The impact of boom section width was investigated by using simulated weed infestation maps with various weed coverage rates. Herbicide applications were simulated combining these virtual maps with various boom sections widths and various theoretical spray patterns. The objective was to quantify the herbicide reduction possibilities and potential under-application areas. Simulation derived results are analyzed using three indicators: i) the ratio between herbicide amount in the case of a targeted application and the amount deposited in the case of a full application, ii) the…
Les transferts d’azote dans le sol à partir d’engrais granulaires dans un contexte d’étude de l’intérêt des apports localisés pour favoriser la régulation des adventices
AGROSUPSPEEAGESTAD; Dans un contexte de mise en oeuvre de techniques spatialisées au sein d’une parcelle cultivée et dans le cadre de l’étude de la régulation des adventices par la compétition pour l’azote, une synthèse bibliographique a été réalisée dans le but (1) d’identifier les modes de placement de l’engrais et leur impact sur la croissance de la culture et des adventices ; (2) de recenser les modèles existants pour simuler le mouvement de l’azote dans le sol ; (3) de repérer les travaux portant sur les transferts à partir de granules d’engrais.
Optimizing Hough transform for fertilizer spreading optical control
International audience; In Europe, centrifugal spreading is a widely used method for agricultural soil fertilization. In this broadcasting method, fertilizer particles fall onto a spinning disk, are accelerated by a vane, and afterward are ejected into the field. To predict and control the spread pattern, a low-cost, embeddable technology adapted to farm implements must be developed. We focus on obtaining the velocity and the direction of fertilizer granules when they begin their flight by means of a simple imaging system. We first show that the outlet angle of the vane is a bounded value and that its measurement provides the outlet velocity of the particle. Consequently, a simple camera un…
Intra-row weed detection in wheat at early growing stage using imaging system
AGROSUPSPEEAGESTAD; In the present agroecological context, the reduction of herbicide uses becomes a substantial issue. For weed control and site specific weed management the development of new technologies is required to identify individual plant. Although many crop/weed discrimination methods have been developed, the automatic intra-row weed detection is still a challenge, particularly in wheat. An imaging system is developed to detect black grass in wheat at early growing stage. The technique mimics the method used by a human expert in such conditions. Thus, the hypocotyl diameter was used as distinguishing criterion. For experiments, the seeds of black grass and wheat were sown in recta…