What are special crops?
The term ‘special crop’ covers all crops that are grown outside the usual production of e.g. cereals, root crops, oilseeds and fodder plants. The cultivation of special crops is not possible on every site due to the special requirements of the plants and is also often labour-intensive and costly. Many special crops are also permanent crops and are therefore cultivated outside the usual crop rotation. Special crops include wine, vegetables, fruit and hops.
Greening and catch crops in viticulture
Greening mixtures' function:
- Deep rooting to looses soil compaction
- Minimise the risk of erosion
- Minimise nitrate leaching and provide nitrate as required
- Improve nutrient and water retention capacity
- Maintain and increase biodiversity
- Ensure the soil's bearing capacity
What to consider when selecting greenery?
- Site requirements
- Soil type
- Water retention capacity
- Weather conditions: Amount and distribution of precipitation
- Microclimate
- Soil conditions
- pH value
- Soil organic matter content
- Duration of greening
Advantages and objectives of greening
- Erosion protection
- Formation of soil organic matter
- Improvement of soil structure
- Promotion of biodiversity
- Settlement of beneficial organisms
- Nitrogen fixation through legumes
- Reduction of the risk of nitrate leaching
- Higher water retention capacity
- Improved nutrient storage capacity
- Improved bearing capacity
- Reduction of chlorosis, stem rot and botrytis
Possible challenges
- Competition for water and nutrients during the vine's main requirement phase
- Declining growth performance of the vine
- Premature leaf yellowing possible
- Lower yields and quality of the vine in unsuitable locations
- Insufficient storage of nitrogen compounds in the berries and reduced formation of reserves in the wood, whch can lead to fermentation problems
Forms of greening
- Part-time greening
- Winter greening
- Summer greening
- Permanent greening
- Lawns
- Clover-grass mixtures, multi-purpose mixtures
- Re-vegetation/ rotational revegetation
- Mixture of part-time annd permanent vegetation
- Natural revegetation
- Site flora
Information on sowing, care and cultivation for permanent greening
- Optimum sowing date: April to mid-May
- Leguminous mixtures can also be sown in August to maintain trafficability and bearing capacity
- Sowing of pure grasses possible until October (after the grape harvest)
- Shallow seedbed preparation
- Seeding width: 70 - 80 % of the tramline for less tall crops
- Maximum growth height during vine vegetation: under-grasses 20 - 30 cm, clover in the aisle 30 - 60 cm and under the row 20 - 40 cm
- Minimum cutting height: under-grass 5 cm, clover 10 cm
- In dry phases, superficial cultivation (2 cm) with the roundabout harrow
- Alternate mulching (staggered in time an space): Protection of the fauna
Information on sowing, care and crop management for winter greening
- Sowing usually approx. 4 weeks before the start of the harvest (mid to end of July), this ensures trafficability
- Sowing on areas where permanent greening is not possible
- In conjunction with permanent cover crops only in every second aisle
- Usually no pruning necessary before the grape harvest
- Mulching or rolling at the time of vine budding = brings higher stands hinder the flow of cold air (frost demage)
- Seeding width approx. 15 cm less than working width for later ploughing
Ideal for rapeseed crop rotations