A network of experimental fields in northern and western Switzerland was used to better understand the behavior of various cover crops in diversified environmental conditions. Several species were oriented towards soil cover in autumn (e.g. brown mustard). Others produced an important aerial biomass (e.g. sunflower). Some, with intermediate performance during autumn, had a good soil cover at the end of winter, as black oat for example. Multifactorial analysis allowed us to precise the relationship between cover crops performance and environmental and agronomical constraints. We identified positive correlations between soil covering in autumn and the sum of precipitations 10 days before sowing or intermediate tillage before cover crop sowing. Aerial biomass of cover crops at the time of the first frost was correlated with soil texture: lighter soils were more suitable for high aerial development. No species combined all the advantages expected from cover crops all along the fallow period but species mixtures offer the best opportunities.
Behavior of different cover crops in a network of on-farm trials