Cover crops are grown between vine rows for many reasons: to protect the soil, prevent erosion, suppress weeds and provide nutrition. They also support integrated pest management by increasing biodiversity, supporting pest predators and providing a natural nutrient cycling system to enhance soil and vine health.
Cover crops can have a dramatic effect on access to water by grapevines and as a consequence, can impact negatively on vine vigour and yield. Species selection and management of cover crops can therefore have a significant impact on vineyard productivity and grape quality, and the benefits of cover cropping need to be weighed against negative impacts.
Even with the best information on selection, what works well in most years may be unsuitable in others. For example, perennial cover crops have the advantage that they can be managed by mowing to reduce water use in dry years, but they will also restrict yields compared to cover from mulch in the mid-row. The impact of climate change will add greater complexity to vineyard management, and with the forecast increased severity of summer rainfall events, the requirement for maintaining soil cover will become even more important.
Cover crops are also grown to protect the soil from raindrop impact and prevent erosion. Rolling or mowing the cover crop can effectively protect the soil, but will also impact on soil and canopy temperatures, particularly in relation to frost prevention and summer heat waves. The correct species of cover crop can also be very effective at weed suppression – out-competing other plants on the vineyard floor.
Plant species selected for cover cropping are generally those that are familiar to the grower, are known to perform well in a particular environment, and for which seed can readily obtained. In the past, this has limited the choice to the standard crops grown in arable agriculture such as cereals, legumes, oilseeds and pasture grasses. However, over the last decade the benefit of substituting exotic cover crop species with natives has been recognised.
Cover Crop Finder – online tool
Cover Crop Finder is a decision support tool designed to aid the selection of cover crops suitable for use in Australian vineyards.
Selecting criteria based on the purpose for the cover crop, the minimum rainfall and a choice between perennials or annual crops, you will be presented with a list of cover crops that match your criteria.