Chapter 6: Managing Nutrients & Water Flashcards
1.2.3 - Vineyard Management Options: Managing nutrients and water (72 cards)
1
Q
Identify the vineyard management options that may need consideration at the time a vineyard is established.
A
- Nutrients & Water (soil health, nutrients/weed control, water management)
- Canopy (grape variety, rootstock vigor, planting density, row orientation/vine balance)
- Hazards (too much, too little water; freeze & frosts; too much and too little solar radiation; fires)
- Pests & Diseases
2
Q
What are four considerations to be made when determining soil health?
A
- Soil structure
- How much organic matter and humus is in the soil
- Number of living organisms in the soils
- Total amount of available nutrients in the soil
3
Q
Identify the components of the soil structure.
A
- Good drainage
- Sufficient water-holding capacity
- Sufficient oxygen
- Ability to resist erosion
- Ability to allow roots of vine to penetrate to sufficient depth
4
Q
Define ‘humus’
A
Humus is formed as organic matter (e.g., plant material deposited on the vineyard floor during and after the growing season) that breaks down, supplying nutrients to the soil and improving the soil structure and its water-holding capacity.
5
Q
Explain how humus benefits the soil.
A
- Acts as a buffer between vineyard floor and roots, absorbing moisture falling on the vineyard and allowing it to be released slowly
- Acts as a binder in soils, helping keep fragile soils together, preventing erosion and soil loss
- Prevents soil compaction which might be caused by tractors and machinery
- Opens up the soil, allowing air to penetrate to lower levels and CO2 produced by the roots to escape
- Helps the soil trap nutrients to release slowly to the roots
6
Q
Explain how poor soil health can impact the vineyard
A
Poor soil health can lead to problems with nutrient and water availability and uptake, which leads to poor vine growth and ripening
7
Q
Explain how a vineyard owner addresses soil health
A
- Test soils prior to vineyard establishment
- Test soil annually after vineyard establishment
8
Q
Identify the top three nutrients a vine requires
A
- Nitrogen
- Phosphorous
- Potassium
9
Q
Explain how a vineyard owner addresses nutrient management
A
- Directly apply nutrients (organic or inorganic), i.e., fertilizers
- Promote biological activity and soil structure
- Manageme weeds that can compete for nutrients and water
10
Q
Explain when fertilizers are applied in a vineyard
A
- Before planting to help the growth of young vines
- To established vineyards to correct deficiencies
11
Q
What constitutes an organic fertilizer?
A
- Derived from fresh or composted plant or animal material, e.g., manure or slurry
- Green manure
12
Q
What are the advantages of organic fertilizers?
A
- Cheap or even free
- Some high in humus; therefore, good for soil structure and water retention
- Provide nutrition for soil organisms, promoting living matter in the soil
- Become available to the vine gradually as they break down
13
Q
Define ‘slurry’
A
Manure in semi-liquid form
14
Q
Define ‘green manure’
A
Cover crops that are grown, mown in, and turned into the soil to decompose and provide nutrients
15
Q
Define inorganic fertilizers
A
Manufactured from minerals extracted from the ground or synthetic chemicals, also known as synthetic fertilizers
16
Q
What are the advantages of inorganic fertilizers?
A
- Can be more tailored than organic fertilizers because can be a single or several nutrients
- More readily available to vines because don’t need to be broken down
- Cheaper to transport and distribute because in a concentrated form
17
Q
Identify five methods for controlling weeds in the vineyard
A
- Cultivation
- Herbicides
- Animal Grazing
- Cover Crops
- Mulching
18
Q
Define ‘cultivation’
A
Method of weed control that involves ploughing the soil to cut or distrub the weeds’ root systems
19
Q
What are three advantages of cultivation?
A
- Chemical free
- Can be used in organic and biodynamic viticulture
- Enables fertilizers and, where relevant, mown cover crops to be incorporated into the soil at the same time weeds are removed
20
Q
Define ‘herbicide’
A
Chemical spray that kills weeds
21
Q
Identify three types of herbicides
A
- Pre-emergence
- Contact
- Systemic
22
Q
How do pre-emergence herbicides work?
A
Pre-emergence herbicides
* Persist in the soil’s surface layers
* Absorbed by the weeds’ roots
* Inhibits germination of young seedlings
23
Q
How do Contact Herbicides work?
A
- Sprayed on established weeds
- Kills green parts of weed that it has come in contact with
- Results in death of the plant
24
Q
How do systemic herbicides work?
A
- Sprayed on established weeds
- Taken in by the leaves
- Herbicide travels up and down the weed in the sap
- Whole plant dies
25
What are three advantages of herbicides?
* **Cheap** in terms of labor and machinery
* **Highly effective**, particularly in the under-row area
* L**ess damaging to the soil** then cultivation
26
Identify an example where a weed became resistant to an herbicide
South Africa
Routing use of glyphosate now means growers face a glyphosate-resistant rye grass
27
What are the advantages of animals providing weed control?
* Does not use chemicals
* Can be used in organic and biodynamis viticulture
* Animals provide vineyard with manure
* Animals can be a source of meat for humans
28
Define 'cover crops'
Plants that are allowed to grow (either as natural vegetation or planted) between rows that have a beneficial effect on the vineyard
Cover crops should be matched to the needs of the vineyard.
29
Why are cover crops used in the vineyard?
* Suppress weeds
* Improve overall soil structure
* Compete with vine for nutrient and water availability (in fertile sites)
* Manage soil erosion
* Enhance biodiversity
* Provide surface to drive on
30
What types of cover crops are often used in the vineyard?
* Crops quick to establish and adapt to soil and climatic conditions (California and Australia have indexes for matching)
* Legumes (beans and clover, mustard, peas, vetches)
* Cereals (ryegrass and oats, wheat, barley)
* Natural vegetation
31
What are the advantages and disadvantages of using natural vegetation as a cover crop?
* Pro: Cheap and greater diversity
* Cons: Characteristics aren't known, so not much control
32
What are the four advantages of cover crops?
1. No chemicals
2. Increases soil biological activity and biodiversity in the vineyard (organic and biodynamic viticulture)
3. Influences vine vigor by introducing crop competition (manage so not too much at key times in vineyard cycle)
4. Provides good surface for machinery (especially in climate with high annual rainfall)
33
Define 'mulching'
The spreading of manure onto the vineyard soil to suppress weed growth.
34
What are three advantages of mulching?
* No chemicals (organic and biodynamic)
* Reduces water evaporation from soil (good for dry climates)
* Ultimately a source of nutrients and humus (soil biological activity and soil structure)
35
Under what circumstances is irrigation a necessary component of vineyard design and establishment?
* If vineyard is an area likely to receive very little water through the growing season
* If the vineyard has very free-draining soils
36
From sustainability standpoint, what are some ways to increase the efficiency of water use?
* Use **water-efficient irrigation systems** and techniques with better monitoring of water take-up by the vines (dripper & RDI)
* Use **drought tolerant grape varieties** (Grenache) and rootstocks (140R)
* **Reduce evaporation** (mulch)
* **Reduce competition** (removing weeds)
* Increase humus levels in the soil to **improve water retention** (add organic matter such as compost)
* **Promote growth of vine roots** deep into soil (cultivation)
37
Why is a high salt level in water bad for the vine?
* Increases salt level in soil
* More difficult for roots to take up the water
* Vines become dehydrated
* Green parts start to wilt
* Plant eventuall dies
## Footnote
Particular concern in Australia
38
Identify the four types of irrigation
* Drip irrigation
* Flood irrigation
* Channel irrigation
* Overhead sprinklers
39
How is drip irrigation installed in the vineyard?
* Installed prior to planting
* Narrow water pipes laid along each row and tied to lowest trellis wire
* Drippers fitted at appropriate intervals and positioned far enough away from vines to encourage roots to grow and seek out water
40
What are the advantages of drip irrigation?
* Economic use of water
* Control water supply to individual rows or blocks - more tailored management and higher yields and quality
* Supply liquid fertilizer (fertigation)
* Used on slopes
41
Define 'ferrigation'
Where liquid fertilizer is added to the water supply via a dosing pump and applied via irrigation (drip or overhead)
42
What is flood irrigation?
* Water is stored behind a sluice
* At scheduled times, released to flood the vineyard
43
What are the pros and cons of flood irrigation?
**Pros**
* Cheap to install and maintain
**Cons**
* inefficient as a lot of water not used by the vine
* only used on flat or gently sloping land
44
Identify a region that uses flood irrigation
Mendoza (and many Chilean vineyards) – ample water from the Andes
45
What is channel irrigation?
* Narrow channels dug alongside rows of vines
* Water directed into them from header channels
* Header channels supplied from feeder canals that traverse the uphill side of the vineyard
46
What are the pros and cons of channel irrigation?
**Pros**
* Can be more efficient than flood irrigation
**Cons**
* Not suitable where water supply is limited
* Channels get easily damaged by tractors and implements
* Channels easily filled up with foliage that needs to be removed ($ labor)
47
Identify a region that uses channel irrigation
Common in Argentina – ample water from the Andes
48
What are the advantages of overhead sprinklers?
* Shower water over the vineyard
* Can be used for frost protection (aspersion) – alone can be a deciding factor
49
What are the disadvantages of overhead sprinklers?
* Expensive to install and maintain due to water pressure needed
* Uses large amounts of water as evaporation levels are high when the water is sprayed through the air before landing on the crops
* May increase humidity levels which may exacerbate disease levels
50
Explain how water stress can be used in the vineyard
Dry climates have the option to put the vine under mild stress at appropriate times if they control the water supplied to the vine via irrigation.
Plentiful water in the spring encourages establishment of large leaf surface area to support production of high yields; whereas mild water stress can be desirable between fruit set and véraison to stop the growth of shoots and encourage grape development and ripening.
51
Define 'regulated deficit irrigation'
System of timing and regulating amount of irrigation so that a vine is put under mild to moderate water stress for specified time within the growing season
52
When is RDI used in a vine's annual cycle?
Usually scheduled **between fruit set and véraison** to limit further shoot growth and encourage grape development
53
What are the advantages of using RDI?
* Better control of vine growth and grape development
* Use less water
* Mild water stress between fruit set and véraison beneficial
54
Define 'dry farming'
For grape growers in areas with limited rainfall during the growing season, it's the choice not to use irrigation.
## Footnote
Dry farming can lead to lower yields but potential improved grape quality
55
Explain how vineyards manage too much water
* Fast-draining soils
* Artificial drainage system
* Leave natural vegetation to grow or plant specific crops to provide competition for water, leaving less available for the wine
* Improve soil structure and remove plough pans to better regulate water drainage
56
Explain how artificial drainage systems are used in the vineyard
* Done before planting
* Cost of installation and maintenance typically offset in medium term by having healthier, better-balance vines that are better able to consistently ripen grapes
57
Identify the core benefit to good drainage
* Aids mechanization in the vineyard by providing better surface to drive on
* Reduces soil compaction that results from driving on wet soils
58
Define 'canopy management'
Organization of the vine's shoots, leaves, and fruit in order to maximize grape yield and quality
59
What are the six key aims of canopy management?
1. Maximize effectiveness of light interception by the canopy
2. Reduce shade within the canopy
3. Produce a uniform microclimate to encourage ripening
4. Promote balance between vine's vegetative and reproductive funtions
5. Arrange canopy to facilitate harvest whether for machine or hand
6. Promote air circulation through canopy
60
How can dense canopies increase fungal disease pressure?
* Dense, shaded canopies dry out more slowly after rainfall or morning dew and provide suitable conditions for fungal diseases to develop
* Dense canopies also more problematic when spraying fungicides because difficult to ensure fungicide reaches all areas of canopy
61
What are the disadvantages of organic fertilizers?
* Requires labor to incorporate fertilizers into the soil
* Bulky
* Expensive to transport and spread
62
What are the disadvantages to inorganic fertilizers?
* No benefit for soil organisms
* Do not improve soil structure
* More expensive than organic fertilizers
63
What are the disadvantages of cultivation?
* Reoccuring cultivation can damage soil structure and ecology (breakdown of organic matter and habitats destruction)
* Expensive - skilled labor and machinery
* Encourages weeds to grow back
* Can increase vine vigor (no competition) - also an advantage in low vigor sites
64
What are the disadvantages of herbicides?
* Can potentially **poison** the operator, consumer, and environment
* **Disocurage vineyard ecosystems**
* Weeds can **become resistant** and therefore dosage may need to increase (or different chemicals used)
* Can **increase vine vigor** since no competition
* Not allowed in organic and biodynamic viticulture
65
What are the disadvantages to allowing animals to graze in the vineyard?
* Vines must be trained high enough - or graizing conducted outside growing season
* Expensive to care for the animals
* Animals susceptible to pesticides
66
What are the disadvantages to cover crops?
* Reduction in vine vigor (competition)
* Mowing under-row area difficult (time and labor)
* Unsuitable for steep-sloped vineyards (slippery when wet)
67
What are mulches made of?
Biodegradable materials (e.g., straw or bark chips) that provide nutrients for the vines.
## Footnote
Mulch material with a high nutrient content can be chosen in nutrient-poor vineyards.
68
What are the disadvantages of mulching?
* Bulky, so expensive to transport and spread
* Only effective if applied in a thick layer - so a lot needed
* Can increase vigor because no competition
69
What are the disadvantages of drip irrigation?
* Expensive to install, but maintenance costs are moderate
* Drippers can become blocked (build up of algae, bacteria, or high levels of minerals/salts)
* Required maintenance which means labor costs
* Cannot be used in frost protection (aspersion) as drippers below upper parts of vine
70
RDI is most effective in which regions and on which soils?
Regions with a dry growing season and sandy or loamy soils that dry out and can be re-wet quickly.
## Footnote
RDI isn't useful in regions with high rainfall or clay soils, which take a long time to dry out.
71
What are the disadvantages of RDI?
* Prolonged or extreme stress can lead to yield and quality reduction
* Often results in lower yields
* Costs to monitor equipment
72
Why is RDI a favored technique for black grapes?
RDI can reduce grape size, which increases the ratio of skins to juice, thereby increasing the concentration of anthocyanins and tannins (often seen as signs of quality)
