D1.C.6 Managing Nutrients and Water Flashcards
What are the factors which determine the soil health?
- Structure of the soil (drainage, water holding capacity, oxygen, resistance to erosion, root penetration)
- Amount of organic matter and humus
- Number of living organisms (earthworm and microbes)
- Total amount of available nutrients
What are the sources of organic fertilizers?
- Animal: Manure or slurry
- Plants: Cover crops mown and turned into the soil ( green manure)
What are the advantages of organic fertilizers?
- Cheap or even free
- High in humus, therefore good for soil structure and water retention
- Nutrients become available to the vine gradually
What are the disadvantages of organic fertilizers?
- They need to be broken down into inorganic nutrients by organisms, they require incorporation into the soil, which requires labour
- They can be bulky and therefore expensive to transport and spread
What are the advantages of inorganic fertilizers?
- The nutrients are already in an inorganic form and therefore can be more readily available to the vines
- Cheaper to transport and distribute
What are the disadvantages of inorganic fertilizers?
- They hold no benefit for soil organisms
- They do not improve soil structure
- They are more expensive
What are the methods to control weeds?
- Cultivation
- Herbicides
- Animal grazing
- Cover crops
- Mulching
How does cultivation work to control weeds?
It cuts or disturbs weeds’ root systems
What are the advantages of cultivation?
- This method does not use any chemicals and so can be
used in organic and biodynamic viticulture - It enables fertiliser and, where relevant, mown cover crops to be incorporated into the soil at the same time as removing weeds
What are the disadvantages of cultivation?
- Repeated cultivation can damage the soil’s structure
- It is costly as it requires both skilled labour and machinery
- Disturbing the soil buries seeds, thus encouraging the weeds to grow back
- It can increase vine vigour too much
What are the types of herbicides?
- Pre-emergence herbicides: They persist in the surface layers of the soil but are absorbed by the weeds’ roots and inhibit germination of young seedlings
- Contact herbicides: Sprayed on established weeds, kill the green parts of the weed that they contact, resulting in the death of the plant
- Systemic herbicides: Sprayed on established weeds and are taken in by the leaves. The herbicide travels up and down the weed in the sap and kills the whole plant
What are the advantages of herbicides?
- Cheap
- Highly effective
- Less damaging to the soil structure than cultivation
What are the disadvantages of herbicides?
- Risk of poisoning to the operator, consumer and environment
- Weed resistance (eg glyphosphate resistant ryegrass)
- They can increase vine vigour too much as there is no competition
- Not allowed in organic and biodynamic viticulture
What are the advantages of animal grazing?
- No chemicals
- Animals can provide the vineyard with manure
- Animals can be a source of meat for humans
What are the disadvantages of animal grazing?
- The vines must be trained suitably high or the grazing must be conducted out of growing season
- The animals need caring for if they belong to the vineyard owners, which requires labour
- The animals are often susceptible to vineyard pesticides
What are the functions of cover crops?
- Suppression of weeds
- Improvement of soil structure
- Compete with vine for nutrients and water in fertile sites
- Decrease soil erosion
- Enhance biodiversity
- Provide a surface to drive on
What are the most frequently used cover crops?
- Legumes (beans and clover)
- Cereals (ryegrass and oats)
What are the advantages of cover crops?
- No chemicals and so can be used in organic and biodynamic viticulture
- Increases soil biological activity and biodiversity
- The ability to influence the vigour of the vine by introducing competition for water and nutrients
- The provision of a good surface for machinery, particularly in climates with high annual rainfall
- Decrease erosion
What are the disadvantages of cover crops?
- A reduction in vine vigour in poor soils and dry environments
- The difficulty of mowing the under-row area
- The unsuitability for steeply sloping vineyards, as they are slippery when wet
Mulches are usually made of which kinds of materials?
Biodegradable materials like straw or bark chips
What are the advantages of mulching?
- No chemicals and so can be used in organic and biodynamic viticulture
- Reduce water evaporation from the soil, which can be advantageous in dry climates
- It can ultimately be a source of nutrients and humus
What are the disadvantages of mulching?
- Expensive to transport and spread
- It is only effective if applied in a thick layer, so a lot can be needed
- It can increase vigour too much
In which conditions, irrigation is necessary and should be a part of vineyard design?
- Areas that is likely to receive very little water through the growing season
- Areas with very free-draining soils
Some EU GIs permit irrigation only..
In emergency situations ( establishing young vines, drought that threatens the livelihood of grape growers)
What can be done to increase the efficiency of water use in the vineyard and winery?
- Using water-efficient irrigation systems
- Using drought-tolerant grape varieties (Grenache) or rootstocks (140R)
- Reducing evaporation (e.g. by applying a mulch
- Reducing competition (e.g. by removing weeds)
- Increasing humus levels in the soil to improve water retention (e.g. by adding organic matter such as compost)
- Promoting the growth of vine roots deep into the soil (e.g. through cultivation)
- Consideration of ways in which water that is used for cleaning can be re-used
What is the effect of high salinity of the soil? Name one country, which salinity is a problem.
- High salinity makes it more difficult for vine roots to take up water
- Australia
Which type of irrigation is more problematic in case of high salinity? Why?
Drip irrigation, as the salt accumulates at the root zone, rather than being washed deeper into the soil, for example by flood irrigation
What is the most common type of irrigation?
Drip irrigation
How are the drippers positioned in relation with vine? Why?
The drippers are positioned far enough away from the vines to encourage the roots to grow and seek out water.
What are the advantages of drip irrigation?
- Economic use of water
- Possible to control water supply to individual rows or blocks of vines, allowing more tailored management
- Can also be used to supply fertiliser (fertigation)
- Can be used in slopes
What are the disadvantages of drip irrigation?
- High cost
- Clean water is required, otherwise the drippers quickly become blocked
- Some maintenance work is usually required
- They cannot be used in frost protection
What are the advantages of flood irrigation?
- Cheap to install
- Cheap to maintain
What are the disadvantages of flood irrigation?
- Inefficient
- Can not be used on slopes
Compare channel irrigation with flood irrigation
They are more efficient in terms of water use
What are the advantages of overhead sprinklers?
- More efficient than flood irrigation in terms of water use
- Can be used as a protection from frost
What are the disadvantages of overhead sprinklers?
- Expensive to install and maintain due to the high water
pressures needed - Less efficient than drip irrigation in terms of water use
- Can increase fungal infections
What is regulated deficit irrigation (RDI)?
It is a system of timing and regulating the amount of irrigation so that the vine is put under mild to moderate water stress for a specified time within the growing season
At which time of the vine cycle, regulated deficit irrigation is usually scheduled?
It is usually scheduled between fruit set and véraison to limit further shoot growth and encourage grape development
RDI is easiest at which climate and soil conditions?
- Dry growing season
- Sandy or loam soils that dry out quickly
What are the advantages of RDI?
- Vine growth and grape development can be better controlled
- Less water is used
Why is RDI is often favoured for black grapes?
As it can reduce grape size, which increases the proportion of skins to juice, and hence increases the concentration of anthocyanins and tannins
Why is timing of water application and monitoring of soil water levels is critical in RDI?
Although mild stress between fruit set and véraison can be beneficial, prolonged or extreme stress can lead to reduction in yield and quality
What does “dry farming” refer to?
It tends to refer to not using irrigation in areas with limited rainfall in the growing season (rather than not using irrigation because there is plentiful rainfall)
What are the benefits of installing artificial drainage systems?
- Having healthier, better balanced vines that are better able to ripen grapes consistently
- Good drainage also aids mechanisation in the vineyard by providing a better surface to drive on
What are the other options other than artificial drainage systems, in areas with high rainfall during growing season?
- Leaving natural vegetation to grow or planting specific crops to provide competition for water (cover crops)
- Improving soil structure and removing any plough pans to better regulate water drainage
