Cover crops and green manures are grown with no intention of harvesting their biomass, either partly or completely, at the end of the cropping season. The difference between these two types of crops is their final use. The above-ground part of green manures is incorporated into the soil at the end of the growing period with the aim of returning accumulated nutrients (e.g., nitrogen) or useful secondary metabolites (e.g., glucosinolates) to the soil. Cover crops are grown for different reasons, such as to reduce leaching of nutrients (e.g., nitrate, then also designated as catch crops), avoid erosion, improve soil structure or suppress weeds. A combined use is also possible, a crop can serve first as cover crop (e.g., for weed control) and then be incorporated as green manure (e.g., for nutrient input).
This video explains the power of these crops to control nematodes and provide some potential cover crops species (especially those fast-growing).
The information contained in this tool is relevant for any practitioner working, or considering working with, cover crops and/or green manures.