6.3 Water Management Flashcards
When might irrigation be used?
- Area likely to receive very little water through the growing season
- Areas with very free-draining soils
Why is it best to establish an irrigation system in a new vineyard as opposed to an establish vineyard?
Can be difficult because of potential disruption to the vineyard in order to lay pipes.
What restrictions are there on irrigation use?
Some EU GIs do not permit irrigation or only allow it for emergency situations (establishing young vines, drought that threatens the livelihood of grape growers)
Where might water for irrigation come from?
Many sources, such as a nearby river, lake, reservoir or bore-hole
What 6 steps can be taken in the vineyard to increase the efficiency of water use?
- Use of certain water-efficient irrigation systems and techniques combined with better monitoring of water take-up by the vines (e.g. dripper systems and regulated deficit irrigation)
- use of drought-tolerant grape varieties (e.g. Grenache), and rootstocks (e.g. 140R)
- Reducing evaporation (e.g. by applying a mulch)
- Reducing competition (e.g. 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).
Why is it problematic when the irrigation water is high in dissolved solids? What must be done?
Give an example of a type of solid that would be problematic in soil.
- can block sprinkler and drip irrigation systems, therefore needs settling and filtering before use
- e.g. mud
Why is it problematic when the irrigation water has a high level of salinity? For which types of irrigation is this most problematic? Where is this a problem?
- This increases salt levels in the soil
- Makes it more difficult for vine roots to take up water
- Vine becomes dehydrated
- Green parts start to wilt and eventually die
- Most problematic for: drip irrigation (salt accumulates at the root zone, rather than being washed deeper into the soil, for example by flood irrigation)
- Australia
What is the most common form of irrigation?
Drip irrigation
Describe drip irrigation.
- Thin water pipes are laid along each row, typically tied to the lowest trellis wire.
- Drippers are fitted at appropriate intervals.
- Far enough away from the vines to encourage the roots to grow and seek out water
- If positioned near vine trunk, roots will simply collect near the trunk where the water falls.
Name 4 advantages of drip irrigation.
- Permit an economic use of water
- Possible to control water supply to individual rows or blocks of vines, allowing more tailored management of the vineyard and thus potentially higher yields and quality
- Can also be used to supply fertiliser (liquid fertiliser is added to the water supply); this is called fertigation
- Can be used on slopes
What is fertigation?
When liquid fertiliser is added to the water supply and distributed through drip irrigation
Name 4 disadvantages of drip irrigation.
- Installation costs are relatively high, but maintenance costs are moderate
- Clean water is required, otherwise the drippers quickly become blocked
- Drippers can gradually become blocked by algae, bacteria or high levels of minerals and salts; therefore, some maintenance work is usually required
- Cannot be used in frost protection (aspersion) as the drippers are below the upper parts of the vine.
What is flood irrigation? What are the pros and cons?
- Water is stored behind a sluice and at the scheduled time released to flood the vineyard
- Pros: Cheap to install and maintain
- Cons: inefficient as a lot of the water is not taken up by the vine; can also only be used on flat or gently sloping land
What is channel irrigation? What are the pros and cons? Name a region that uses this method.
- Water flows down furrows dug between the vine rows
- Pros: More efficient use of water
- Cons: Not suitable where water supply is limited
- Argentina (abundance of water from the Andes)
Name 4 methods of irrigation.
- Drip
- Flood
- Channel
- Sprinklers