COVER CROP, or cover crops can be defined as a non-economic crop which is deliberately grown in combination with the cash crop to enhance it (Chuck A Ingels and Karen M Klonsky (1998, p3). In vineyards, cover crops are grown between the rows of vines which, via their grapes, provide the cash crop.
TYPES OF COVER CROPS / Ingels and Klonsky (ibid.) say most cover crops are classified as winter or summer annuals, which germinate and die in one year or less, or perennials, which live for three or more years. Often, cover crops are also classified based on taxonomy, mostly being either legumes (Fabaceae family) such as clovers and vetches, or grasses (Poaceae family) such as barley and fescues. Other plant types used as cover crops include brassicas (Brassicaceae family) and phacelia (Hydrophyllaceae family). In addition, weeds are often simply allowed to grow and be managed like a cover crop. This “resident vegetation” offers some of the benefits of a sown cover crop, such as improved water penetration, although the plant species may vary greatly and may include undesirable weeds, the authors say.
WHY COVER CROPS? / They stabilise and improve soil structure, prevent erosion, improve water and nutrient retention, make access to the vineyards easier in wet weather, enhance soil micro-biology, promote biodiversity above ground.
CASE STUDIES / See Weingut Zähringer in Baden, Germany.
Chuck A. Ingels & Karen M. Klonsky, ‘Historical and current uses’ in Cover cropping in Vineyards, A Grower’s Handbook’, University of California Division of Agriculture and Natural Resources, Publication 3338, 1998, p3.