Jensen, Erik Steen
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences
Louarn, Gaetan; Bedoussac, Laurent; Gaudio, Noemie; Journet, Etienne-Pascal; Moreau, Delphine; Jensen, Erik Steen; Justes, Eric
Managing the nitrogen (N) supply in agroecosystems is a critical issue to ensure sufficient food production while preserving the environment. Intercropping is known to be a sustainable means of reducing the use of N-fertilizers. However, managing the N supplied to a crop while optimising the use of N by different species in a mixture remains a challenge. This is partly due to the difficulty of assessing the N requirements of each component in the mixture separately in order to correctly drive the performance of the whole system. The methods used to assess plant N nutrition status were initially developed for sole crops. In this review, i) we present different approaches adapted from these previous works to determine the N nutrition status of crops in intercrops; ii) we then compare the predictions of some of them, based on a European database of experimental results regarding cereal-grain legume and perennial grass-legume mixtures; and iii) we discuss the interests and limitations of current indices for mixed crops. We conclude that no single approach is currently valid to assess the N nutrition status of crops within the entire range of possible mixtures explored by farmers. However, some indices based on the N dilution theory perform well regarding the most common situations of balanced binary intercrops. Further research is now needed to properly address the cases of complex mixtures and severely shaded crops.
Nitrogen nutrition index; Diagnosis; Intercropping; Nitrogen stress; Critical dilution curve; Cereal-legume mixture
European Journal of Agronomy
2021, Volume: 124, article number: 126229
SDG2 Zero hunger