Battling Weeds with Fungi and Woodchip

Weeds are one of the biggest challenges for an organic vineyard. Without the use of herbicides weeds can quickly take over and compete with the vines, which is especially bad news for new vines trying to get established.

Agricultural soils which have been ploughed for many years often end up being dominated by bacteria rather than fungi. There is a correlation between plants and their preference for soils that are dominated by bacteria versus those that are fungal dominated or neutral. Since the path from bacterial to fungal domination in soils follows the general course of plant succession (see earlier blog on the Soil Food Web), it is possible to predict what type of soil particular plants prefer. In general, perennials, trees, and shrubs prefer fungal dominated soils, while grasses and weeds prefer soils dominated by bacteria. Vines generally do best in soils that have an F:B (fungal/bacteria) ratio of between 2:1 and 5:1.

At the moment the vineyard is heavily dominated by bacteria which means that weeds will quickly dominate if nothing is done to control them. Longer term the fungal content of the land will naturally increase and we will try and help this process by using compost teas with a high fungal content. In the short term however we are just about winning the battle by using huge amounts of woodchip as a mulch and have just finished spreading over 1000 m3 of the stuff on the 12,600 newly planted vines.

Couch Grass - an Organic Nightmare

The dreaded couch grass has appeared on the perimeter of the vineyard. Couch grass is a noxious weed whose spiked flowers somewhat resemble an ear of wheat in structure. It is a perennial grass and the rhizome spreads rapidly in all directions in light soil, sending up leafy stems from the nodes.

Couch can be a nightmare for organic growers as we can't use herbicides and the only real way of removing it is a lot of hard work on your hands and knees pulling out the roots.

Fortunately it's not too bad at the moment and Alex has been able to pull out most of it. Fingers crossed it won't spread into the vineyard.

Frost attacks the Vineyard

For the second night running the vineyard has suffered a fairly severe frost causing damage to buds and leaves on the vines. Were not sure how much damage has been done but it will become apparent during the next few days as leaves will appear burnt and buds will shrivel and fall off where the frost has attacked them.

New shoots will appear in a few weeks time but they won't be as vigerous or fruitful as the first ones. This doesn't matter too much this year but next year (our first cropping year) it could significantly reduce yield and leave less time for the fruit to ripen.

Severe frost this late in the year is unusual in Surrey but we will have to make sure that from next year onwards we are well prepared to minimise any damage. This may involve using bougies (french for candle - a sort of oil lamp) which are placed in the rows every 12 metres. By my calculation we would need over 3000! Alternatively there are machines called frostbusters but they are expensive. Spraying the vines with water in the early hours so that a protective layer of ice forms around the buds can also be effective but it requires an enormous volume of water and is therefore not very environmentally friendly.

So that we know how low the temperature is getting we will be installing a simple weather centre with a mobile phone connection which will send a warning alarm to me and Alex when the temperature is getting too low. This will inevitably mean a few early mornings in years to come as we will have to be up at about 3.00am to light the bougies or spray the fines!

Experiments are taking place with electrical and microwave heaters which we will investigate further.

No time to vote - 12,600 more Vines Planted!

Oblivious to the election results, we were up at 5am yesterday morning to complete the planting of the vineyard. Thanks to Volker Scheu and his satellite guided planting machine, we managed to finish the planting of another 12,600 vines on about 7.5 acres in little more than 24 hours.

The new vines are mainly the traditional champagne varieties including:

   Varietal                     Rootstock     No.
   Pinot Meunier 865      41B             1,250
   Pinot Meunier 925      41B             1,250
   Pinot Noir 115            Fercal         1,100
   Pinot Noir 459            Fercal         1,100
   Pinot Noir 870            Fercal         1,100
   Pinot Noir 872            41B            1,100
   Chardonnay 95           Fercal         1,450
   Chardonnay 124         41B            1,450
   Chardonnay 277         41B            1,450
   Syval Blanc                SO4           1,175

We've also planted 175 Pinot Gris as a bit of an experiment.

Before planting, the roots of the vines were soaked in compost tea and then dipped in a solution of mycorrhizal fungi which breaks down organic matter releasing nutrients (particularly phosphates) and can also significantly increases root capacity.

 
The planting nearly didn't happen as Volker's machine got a puncture on the way to the vineyard. However, thanks to Philip and Gary, we were able to replace the wheel with one from Gary's tractor which allowed us to complete the planting while a new tyre was being sourced and fitted.
 
Thanks to all the team (including Volker and his planters, Alex, Stephen, JB, Philip and Gary) for a huge amount of effort and an excellent result.

Volker and the team with Philip (left) and Stephen and Alex (right)

 
In total we now have some 21,000 vines planted on nearly 13 acres. During the next couple of weeks we will be spreading 90 tonnes of organic compost on the vines, together with a huge amounts of woodchip mulch which will hopefully keep the weeds at bay!

Bud Burst and Jack Frost

Bud Burst - Pinot Noir

Spring sees the vines awake from their dormant period over winter. As sunshine increases, the buds begin to burst. The majority of our vines at now at the stage of "full swell". Some are at "bud burst" and a few are showing "first leaf".

This is a risky time in the vineyard as a severe frost can burn the buds. At worse this can result in the entire season's crop being lost. Whilst global warming is generally assisting viticulture in the UK, too much sunshine to early in spring means that the vines will be vulnerable to frost for longer.
 
Various attempts are often made to protect against frost including lighting oil heaters in the rows, spraying the vines with a chemical solution to form a seal around the buds, or even using helicopters to get air circulation. We can't use the chemicals or the helicopter as were organic so I guess I might be up tonight lighting oil lamps!

Let's hope that Jack Frost won't catch us out!

Something from Dr Who? No - Our New Sprayer!

Looking like something from Dr Who, the sprayer for the vineyard arrived last week.

We decided to go for a second hand model (supplied by Nick Seymour) to get some experience of spraying compost teas before investing in a new one. Already we have had some difficulties, with the larger particles in the tea blocking the nozzles but Alex is confident that we will be able to overcome this little problem by straining the tea before putting it in the tank.

The sprayer has to be kept spotlessly clean so that the organisms in the tea don't die, which means thoroughly washing it (as well as the brewer) after each application. We'll be giving it another go next Saturday.

The Best Brew in Surrey!

Vino and Joel from Laverstoke with the Compost Tea Brewer

Last week we took delivery of our very own compost tea brewer, courtesy of the team at Laverstoke Park.

Compost tea is a water based extract of compost that is "brewed" aerobically to extract organisms (bacteria, fungi, protozoa and nematodes). This is done by filling the tank with de-chlorinated water and submerging some woody compost into it (contained in a fine mash bag). Air is then pumped into the tank from the bottom (a bit like a bubble bath) for 24-36 hours.

Feed stimulants can be added to the brew to promote growth of specific organisims. In our case we're using fish and seaweed extracts to encourage the growth of fungi. When the tea is sprayed on the vines these organisms dominate the surfaces of the leaves which hopefully prevents disease-causing organisms from establishing, particularly mildews. Compost tea also provides plant food which aids healthy plant growth, strengthens the plant's defence systems and, with the addition of beneficial organisms to the soil, will help the recycling of organic matter, improving soil structure.

The tank has a capacity of 1000 litres which should be enough to spray the vineyard when we have planted the full 13 acres and the canopy is fully developed. We are planning to make a brew about every two weeks.

During the growing season Laverstoke will be analysing our compost tea every month to ensure that it has the right level and type of organisms for our soil.

We have no intention of competing with the local excellent hop brewery near Shere, or indeed Philip's magnificent brew of "English Breakfast", but hopefully our compost tea will be just the right brew for the vines.