CHN-conduite

Arvalis Institut du Végétal has been developing since 2017 an integral management tool of nitrogen (N) fertilization in wheat, called « CHN-conduite ». CHN-conduite is based on an innovative coupling between a crop model (« CHN »), and data from satellite sensors to access near real-time diagnostics-prognostics of plant nitrogen status. CHN-conduite does not rely on a forecasted N dose, in favor of a more flexible approach which makes it possible to adjust nitrogen inputs to the real crop needs on the basis of objective criteria, taking into account the particularities of the crop context and the year's climate. It includes daily estimation of soil N and water stocks available for the crop, as well as impacts of N or water deficiency on crop growth. Several elements are considered in the reasoning of the tactical advice, as the notion of minimal nitrogen nutrition index path, and forecasted rainfall for the next 15 days. Real-time access to biophysical variables from sensors (leaf area index and canopy chlorophyll concentration) through digital images, and the ability of the CHN model to integrate this information, offer the opportunity to establish a relevant N rate advice at a intra-field scale.