Managing the soil of your vineyard helps to keep the ground in good condition physically, chemically and biologically. Traditional practices consisted—and still consist—of tilling the soil in the inter-rows (the spaces between vine rows) and under-rows (along the rows), the ultimate aim being to reduce competition between weeds and the vines for water and nutrients. Vines actually occupy only a small proportion of any vineyard. The remaining portion is otherwise largely unoccupied and therefore susceptible to colonisation by other plants (namely weeds). For a number of years, however, various soil management techniques have been adopted that often integrate distinct practices for the inter-rows and under-rows of the vineyard.
There is no sure-fire system for soil management: whichever system to use depends on the climate, soil type, gradient, vine variety, training system, the age of the plants, and so on. In addition, nowadays managing the inter-rows and under-rows of a vineyard is not only a question of controlling weeds, but also takes into account numerous aspects such as grape quality, soil fertility, environmental protection, and ease of access to the vines. In this article, we talk about the practice of grass cover-cropping and look at how to tidy the under-rows and inter-rows of a vineyard.
Why grassing the under-rows of a vineyard is useful
Grass covers the soil of the vineyard with turf. It is a form of intercropping between grass and vines, which of course triggers competition between them, but also generates an interaction with positive effects on:
soil fertility, thanks to greater availability of organic matter and nutrients, less compaction, active soil microorganisms, etc.
plant vigour, by regulating the quantity of grapes produced, thereby benefiting quality
vine health, due to fewer nutritional deficiencies and diseases, greater sun exposure, etc.
environment and landscape, thanks to reduced use of herbicides, soil conservation, etc.
Grass cover-cropping is a flexible technique that you can adapt to your own vineyard by varying the species, area and duration of the grass cover. Spontaneous grass cover-cropping is not entirely controllable: some grasses provide less than optimal cover (patchy growth, insufficiently hardy, short-lived, etc.), whereas others are too competitive or can favour diseases (such as blackwood). Therefore, to obtain maximum benefits, artificial grass cover-cropping may be preferable, which involves selecting grass varieties based on the characteristics of the vineyard.
Grass cover-cropping can be used over the entire vineyard, by alternating grassed/tilled rows, or by grassing only the inter-rows. Under the rows it can be alternated with tilling, weeding or mulching. Last but not least, the grass cover can be permanent or temporary. Here you will find a focus article on the advantages of grass cover-cropping combined with soil cultivation.
How to tidy the under-rows of a vineyard
Grass cover in the vineyard can be managed by mowing it, ideally 3-4 times a year, and leaving the clippings on the ground. Mowing is a must between the vegetative resumption and grape maturation, especially if the soil is not very fertile and there is little water available. Periodic mowing helps to reduce competition between grass and vines, whilst also ensuring that a microclimate favourable to parasites is not created at the foot of the vine trunks. Last but not least, it also makes it easier to carry out other jobs that need doing in the vineyard. From the point of view of vineyard management, compared with conventional tilling, grass cover-cropping is a faster and less expensive solution. In addition, it reduces the need for pruning, by controlling plant vigour.
Tidying under-rows in the vineyard entails some risk to the vines, insofar as it can damage their bark and roots. In the various stages of vineyard management, it is important that the plants are not subjected to stressful situations, so as to prevent a series of fungal diseases known as vine wood diseases, including black measles. Therefore, when tidying the inter-rows and under-rows of the vineyard, handheld tools are preferable to using machinery that may cause accidental knocks or wounds (and thereby lead to infections).
Compared with the use of agricultural machinery, resorting to manual tools—such as a brushcutter or flail mower—is certainly a more demanding job. This is because it can be tiring, slow, precision work, and therefore it is best suited to small, family-run vineyards. When cutting grass around vine stems with a brushcutter equipped with cutting line, don't get too close, to avoid causing damage or trauma to the vine: leave the grass nearest the trunk and finish the job by hand afterwards. Just to be on the safe side, you can protect the stems of vines with a suitable shelter, or by wrapping them with nonspecific plastic tubing.
A brushcutter with cutting line will do a more accurate job: here you can find out more about the various types of brushcutter heads.
For cleaning vineyard under-rows, you may be better off with a backpack brushcutter. As regards the handgrip, a model equipped with handlebars will give you more control over its movement. Here is an article about whether to choose a single or double handgrip.
When tidying under-rows on the vineyard, grass cutting is less damaging to vine stems and roots than tilling the soil (which you can do with a rotary tiller on small plots). Furthermore, with a brushcutter, mowing is possible even if the spaces are narrow, the terrain is sloping or stepped, or if the ground is stony (in which case, always follow safety precautions and wear protective clothing, including a face shield or protective glasses).
Don't mow if you expect rain, which stimulates grass regrowth, otherwise you will need to mow again before long. However when tidying under rows with a brushcutter, it is advisable to cut when the soil is temperate (i.e. slightly damp) rather than dry, so as to kick up less dust.
By contrast, for tidying inter-rows you can use a flail mower or garden tractor. On that subject, you can read our articles on using a flail mower to mow grass and which garden tractor to choose for the vineyard.