@misc{orgprints39712, series = {ReMIX Practice abstracts}, month = {April}, title = {To N-fertilize cereal-legume intercrops or not? (ReMIX Practice abstract)}, author = {Eric Justes and Laurent Bedoussac}, pages = {1--2}, year = {2020}, keywords = {cropping systems, diversification, arable farming, low input agriculture, Intercropping, cereal crops, legumes, nitrogen, nutrient management}, abstract = {Outcome Intercropping cereal-legume usually results in a higher cereal grain protein concentration compared to sole crop cereal, and the greatest benefit is always obtained without N-fertilizer. Practical recommendations ? The efficiency of synthetic N-fertilizer is generally high ({\ensuremath{>}} 75\% of N applied). It always increases the proportion of cereal in an intercrop with legumes, regardless of the sowing density and pedoclimatic conditions. ? The efficiency of organic N-fertilizer is always low ({\ensuremath{<}} 20\%), so it is not relevant to apply in organic farming. ? For winter intercrops (e.g. wheat-winter pea), the N fertilization must be adapted and based on the: i) proportion of species observed in March, ii) grain yield targeted, and iii) proportion of the two species expected at harvest. To increase cereal grain yield, N-fertilizer could be applied during stem elongation (40-80 kg N/ha), while to increase the cereal grain protein concentration, it should be applied at earing (30-50 kg N/ha). ? For spring intercrops (e.g. spring barley-spring pea), no N fertilization is generally required, except to ensure a high proportion of cereal grains at harvest by applying N-fertilizer at the end of tillering (30-60 kg N/ha). Practical testing/ Farmers? experiences Farmers should try different N fertilization rates and/or times, for example, in strips across a field, to visually compare the effect of N fertilization on yield, species proportion and cereal grain protein concentration. Start with a small number of rates and/or times (including no fertilizer) and repeat the test for more than a year to improve know-how.}, url = {https://orgprints.org/id/eprint/39712/} }