Nécessité d’un changement de paradigme pour étudier la nutrition et la fertilisation azotée des cultures / Need for a paradigm shift to study crop nutrition and nitrogen fertilization

Abstract

Nitrogen fertilization of crops has long been based on a statistical analysis of the response of their yield to increasing doses of fertilizers. This prognosis has led to an insurance practice applying excessive doses of nitrogen so as not to penalize yields. A method for predicting the nitrogen balance of a crop has been developed to correct this trend but remains too highly imprecise. Diagnosis of the nitrogen nutrition status of a crop has recently emerged, reducing the uncertainty linked to the variability of local conditions. This diagnosis, integrated into decision support algorithms, makes it possible to apply fertilizers only “where” and “when” the nutritional status of the crops requires it. This precision must make it possible to achieve the targeted yields while minimizing the environmental impacts.