Winegrowers Supplies - Organic techniques
The characteristic of organic viticulture in Germany is a mix of permanent green cover crops in the vineyards, which is practised everywhere. Permanent cover crops have major advantages for the whole production system.
1. When the cover crop is sown the soil is generally loosened and the green crops then stabilises the soil structure. The advantages of a stable soil structure are among others an enhanced capability of collecting and storing water.
2. A high root density enhances soil life. Biological activity is an important basis for the nutrient supply of the vines. The use of legumes ensures nitrogen supply.
3. Only a green cover crop can facilitate a real biodiversity in the vineyard. It is an essential basis for a stable balance of predators and pests.
Organic viticulture has clearly proven that the plants can be fed without chemical fertilisers: by using various combinations of organic fertilisers; by loosening the soil; by using a mix of green cover crops. Especially as regards cover crops many different techniques – often combinations of individual techniques, adapted to various locations - are practised successfully.
This type of soil management is very demanding in terms of requirements for machinery. Alternating management of the space between the vine rows has proven to be highly advantageous: on the one hand because certain measures (like mulching or soil management between every second row of vines) have less grave effects on the whole system, and on the other hand because with combination of various fine tuning measures is possible (e.g. green cover crops between the vine rows, no cover crops in the rows).
As regards pests the efficiency of the application of ecological principles is fully
exploited. The optimum balance between pest and predators can be enhanced through:-
- use of a mix of green cover crops in the vineyard with the promotion of a high diversity of flowering plants (as habitats and as feeding bases for predators).
- care for hedges and other habitats in the vicinity of the vineyard.
Thus the renunciation of insecticides in organic viticulture is possible. This represents one of the biggest successes of organic viticulture. Luckily, especially in this field conventional farming has followed on.
On a regional level the grape berry moth must not be underestimated, but because of the high biodiversity it has been possible to reduce the threshold of the first and second generation. Also available are effective antagonists (like bacillus thuringiensis and confusion by pheromones. The organic wine growers prefer, however, BT.
A mix of green cover crops, a high root density, and the harmonious nutrition of the vines reduce diseases like chlorosis and stem dieback, virus diseases and several fungus diseases like botrytis.
A special challenge to organic viticulture are the vinifera
varieties which are highly susceptible to downy and to powdery mildew. This fact does not prove that
the concept of organic viticulture is wrong; it rather shows that the basic rule of the right choice
of varieties is being neglected (more than 90 % of the organic vineyards in
Germany are planted with vinifera varieties). As a result the German organic
wine grower is very busy with plant protection measures all summer long. Using
climatic data for prognoses has become a standard. A weak point is, however,
that the date of the primary infection of downy mildew still cannot be
determined for sure.
Apart from the high risks the biggest disadvantages are the high number of applications, the high labour and machinery input and soil compaction between the vine rows. Solutions are urgently needed. Therefor the wine growers are, of course also hoping for research results on the following themes:-
- efficient biological pest control agents.
- mobilisation of the intrinsic vitality of the vinifera varieties via systemically induced resistance through natural agents.
- use of fungal antagonists.
Fungus resistant varieties
All of the above measures can, however, only be short or medium term solutions. The long term solution can only be resistant varieties. Ecovin recommends the cultivation of these varieties in its standards, and for years it has promoted less rigid laws regulating the cultivation of these varieties. It also presses the state breeding stations to continue intensive work on these varieties. The fungus resistant varieties like Regent, Rondo, Johanniter, Bronner as well as further varieties which so far are only known by their breeding numbers give rise to much hope.
The magic triangle 'ecology, quality and economy' must
certainly be balanced. On a macro-economic level organic viticulture is certainly
highly economical. The organic wine growers are, however, not rewarded for their
efforts in an adequate way.
On a farm level the higher costs which are due to higher input costs for the cultivation techniques are only to a minor degree economically relevant. Lower yields (15 to 20 % less than in conventional viticulture), however, result in higher costs per unit. Per litre of organic wine the costs are around thirty percent higher than for conventional wine.
The state aid programmes (mainly under the EU’s agri-environment programmes like MEKA in the federal state of Baden-Württemberg and FUL in Rhineland-Palatinate; depending on the federal state between around 500 and 750 Euro per hectare and year) can cover these extra costs only to a small degree. The differentiation between the subsidies for integrated and organic farming is far too small, and the incentive for wine growers to convert is not high enough.
Especially because of the higher costs due to the production system higher prices must be obtained when marketing the products.
What are the chances and advantages for organic wine growers?
- Lower quantities always have a positive effect on quality. In organic viticulture the proportion of high quality wine is higher and therefore also the potential for a higher price per bottle.
- Quality is not restricted to the end product in the wine glass. For many customers the fact that a wine was organically grown plays an important role when buying wine.