Date of this Version
Published in Soil Management: Building a Stable Base for Agriculture (2011) 321-337. DOI:10.2136/2011.soilmanagement.c21
Cover crops are used to manage soils for many different reasons and are known by many different names. Cover crops are literally “crops that cover the soil” and one of their first uses was to reduce soil erosion during fallow periods in annual cropping systems. Cover crops are also known as “green manures,” “catch crops,” or “living mulch.” Green manure cover crops are usually legumes that fix N and are grown to provide N to the following cash crop. Catch crops are cover crops that are grown during fallow periods in cropping systems to take up nutrients, especially N, that would be lost if plants are not present. Lastly, living mulches are cover crops that are grown both during and after the cash crop growing season and are suppressed or managed to reduce their competition with the cash crop when it is growing. After the cash crop has matured and before it begins growing again, the living mulch is allowed to grow unhindered. One way to manage living mulches is to restrict them to the “fallow” spaces between crop rows. Orchards or vineyards are sometimes managed with living mulches, but it is also possible to incorporate living mulches into annual cropping systems. Thus, as can be seen from their many names and descriptions, cover crops can fulfill many soil management functions.