grass | amarchinthevines

Version francaise

I wasn’t expecting to add anything to the previous post but on our walks around the area this week I have been struck by the amount of viticulteurs busy with a task that I had not included. So, as I hoped this blog would reflect what I saw rather than just theory I felt that I ought to add this post.

Biodiversité - un analyse démontre qu'il y a plus que 30 espèces de l'herbe dans un mètre carré

Soil in Jeff’s vineyard Peilhan with over 30 types of plant per square metre

So what has been the extra February task, getting rid of grass and weeds (désherbement). A normal task for gardeners but a controversial one for viticulteurs. I have posted many photos over the last few months showing grass growing between vines, not least those of Mas Coutelou. Twenty years ago this was relatively rare but modern viticultural practice reflects concern for the environment and less use of weedkillers etc. It has also been shown that grass (plus other herbs and wild flowers) has benefits for the vineyard; controlling weeds, conserving water and conserving the soil itself by binding it to prevent erosion. The grass can also help to provide competition to the vines forcing them to push their roots deeper into the soil to search for water and nutrients.

As spring seems to be with us already the grass will start to grow soon and viticulteurs want to control it so that it does not compete too much as the vines emerge from their dormancy. The amount of plant material a viticulteur would want will depend upon a number of factors such as the age of the vines as s/he would not want to hinder their growth and development. The nature of the vineyard too will affect the amount of grass you would allow. The viticulteur knows the vineyard and will make the decision as they see fit. Those who follow more reasoned approaches (my choice of words and my bias) do so carefully using strimmers to cut it down or pickaxes and hoes. Some will plough the soil so that the organic matter will provide a form of compost in the soil. I have asked a few winemakers I know and these are their methods. Manu Pageot, for example, will not start to weed until the soil has warmed up a little. Even then he will work by hand or using very light machinery so as not to compact the soil.

Jeff et Manu. ils étudient les herbes semées entre les vignes Cela va aider a garder de l'eau, renforcer la structure du sol et va attrayer les insectes

Jeff and Manu studying the grass Manu sowed between his vines

However, others take a more radical approach using chemicals. I took these photos on a recent walk around Alignan du Vent and Margon. Chemicals have been used to kill the growth and also a method of piling up soil to stop growth. I am not criticising these viticulteurs, they have to work as they see fit though clearly I am not personally sympathetic to their methods.

Chemical spraying to kill off any plant life in a new vineyard

Soil piled up to smother any growth. Note the compaction of the soil by the tractor

The photos below show a vineyard in November (top picture) and then below it you will see the row with the plants having been treated to kill them, changing colour as they die in the middle photo. If you look between the vines in the bottom photo you will see the grass turning to a straw colour.

So to finish,a lovely memory of a more gentle approach to grass management!

(En français)

The Languedoc Roussillon region was struck by huge storms on November 28th. Lightning and thunder which lasted almost a whole day, torrential rain all day (over 210mm at Bédarieux), hail for half an hour, winds well over 100kph. Even local people were surprised by the storm. There are some scary pictures on Midi Libre.

Outside our door in Margon

Puimisson, the stream in the background reached the height of the tree branches

Jeff pointing to debris from the stream in the tree branches

A walk around Margon, our home village, 3 days later showed that many vineyards had been damaged. At this time of the year the vines themselves are not so vulnerable of course, there are no grapes left on there. However, the soils themselves were damaged in many places by erosion.

2. Water standing in the vines

1. Clay (argile) run off on the road

Much of our area has clay soils which are not the easiest to drain. However, many modern agricultural practices exacerbate this problem. Using heavy machinery such as tractors, harvesting machines and large sprayers means that the soils become compacted and, therefore, even more impermeable (photo 2). Inappropriate use of herbicides and weed killers to get rid of grass and other plants means that the soil has nothing to bind it together and, consequently, heavy rain will cause erosion as we see in photo 1. Overploughing will combine both problems.

I remember when I first visited French vineyards 30 years ago that most were like this. Times have changed though and more artisanal, more environmentally aware viticulturists have realised that the soil has to be treated with respect. In a previous post I mentioned that the soil experts Claude and Anne Bourguignon gave a talk recently which I attended. They explained that the soil is what gives a crucial 6% of the vine’s needs which can make all the difference in terms of flavour and quality. Vine roots need to reach down into the soil to extract the water and minerals which they require to grow and to fruit. They confirmed that the best practice is what many winemakers have been doing in recent years. Allowing grass and other plants to grow amongst the vines brings many benefits:

binding the soil, making it stronger and less prone to erosion
stronger soil makes it easier to withstand machinery
competition for nutrients drives the vine roots deeper where more of the species which benefit the plants live
retaining moisture in summer which can also be used by the vines
providing shelter to other wildlife which eat the insects that damage vines and grapes

Covered vineyard with no sign of erosion

Ruts developing between vines

The photos above show how two parcels of vines just metres apart responded to the storms. The difference is obvious.

Vines with shallow roots do not access the deeper minerals and ecosystem. The roots also overheat being nearer to the surface and this can mean that they shut down some of their work and grapes will not ripen so well or evenly.

Yet there are vignerons in the area who have installed or are installing irrigation. This can only compound the problem in a region where there are occasional droughts but not on the scale of Australia for example.

Jeff Coutelou reported to me that there had been no erosion in his vines unlike those of some of his neighbours, the reason may be seen in the photos below.

A stark contrast between the Mas Coutelou vineyard and that of his neighbour

Irrigation pipes run along the vines. Look closely at the channel which has been cut into the soil by the rain.

Water flowing off vineyards which have had the grass removed

The run off from the vines has caused a new stream and channels

Meanwhile Jeff’s vines have drained and there is no damage to soil below

Vine roots washed into the new stream next to the neighbours’ land

Biodiversity – analysis showed over 30 types of grass in one square metre of Jeff’s vineyard.

One sad casualty of the storms was the tree with a bat shelter installed by Jeff. Bats are good friend to vines as they eat many insects which might damage them or their grapes. Encouraging them and other friendly wildife, such as wagtails and hoopoes, helps to keep the grapes in good health. Unfortunately the tree, which was dead, was uprooted and so a new bat home will be established soon.

Bat shelter

And finally how to control that grass and plant life? Ploughing or working the soil is needed at times but there are some novel alternatives. At Mas Gabriel a local farmer brings his sheep into the vineyard at this time of year. And then, as I was driving to Cabrieres the other day I came across this.