Ch 6 Managing Nutrients and Water

Question 1

Managing Nutrients and Water

What does soil health mean?

Answer 1

○ Continued capacity of soil to act as living ecosystem to support plants, animals and humans

Question 2

Managing Nutrients and Water

What are the factors that contribute to soil health

4

Answer 2

• Soil structure - drainage, water holding capacity, sufficient O2, able to resist erosion, allow roots to grow to appropriate depth
• Amount of organic material and humus in soil - decomposing organic material = nutrients; humus = improves water holding ability
• Number of living ogranisms - earthworms/microbes - break down organic matter into humus and inorganic nutrients
• Total amount of nutrients avail for vine to grow

Question 3

Managing Nutrients and Water

What are the soil structure factors that contribute to soil health?

Answer 3

Drainage
Water holding capacity
Sufficient O2
Ability to resist erosion
Allow roots to grow to appropriate depth

Question 4

Managing Nutrients and Water

What is humus?

Answer 4

a dark, organic material that forms in soil when plant and animal matter decays

Question 5

Managing Nutrients and Water

What are issues that poor soil health can cause and what can growers address?

Answer 5

○ Availability and uptake of nutrients and water = poor vine growth and ripening
○ Annual soil health checks - allow corrective measures to improve structure and nutrient levels

Question 6

What form do nutrients have to be in for the vine to use them?

Answer 6

Inorganic

Question 7

Nutrient Management

What are the 3 general approaches to managing nutrients and what are examples of each?

Answer 7

○ Direct application - organic and inorganic fertilizers
○ Promotion of biological activity and soil structure
○ Management of weeds that can compete for water and nutrients - cultivation, herbicides, animal grazing, cover crops, mulching

Question 8

Nutrient Management

Beyond managing water and nutrients, why is weed management beneficial

Answer 8

○ Bare, moist soils best at absorbing heat and releasing at night = reduced frost; weeds and cover crops can increase frost risk
○ Some weeds also hamper use of machinery and people

Question 9

Nutrient Management

What are the 2 kinds of fertilizer, when can they be added and why?

Answer 9

○ Organic or mineral (inorganic)
○ Can be added before planting to help young vines;
can be added to estab sites to address nutrient deficiency

	○ Excessive fert = risk of overly vigorous and/or unbalanced vines

Question 10

Nutrient Management

What is organic fertilizer and what are benefits/considerations?

Answer 10

○ Made from fresh or composted plant/animal material - e.g., manure or slurry (manure in liquid form)
○ Benefits - cheap or free; some high in humus = good for soil structure and water retention; since organic in nature, provide nutrition for soil organisms, slow release of nutrients into soil
○ Considerations - requires labor and incorporation into soil since vines can’t use organic nutrients -> needs to be broken down by organisms; nbutrients only become available gradually (can be good); can be bulky and costly to transport and spread

Question 11

Nutrient Management

What is green manure?

Answer 11

§ Cover crops can be grown and plowed into soil to decompose and add nutrients

Question 12

Nutrient Management

What is inorganic fertlizier?
What are benefits and considerations?

Answer 12

○ Aka synthetic fert - manufactured from minerals from ground or synthetic chems
○ Benefits - can provide a range of single/several nutrients -> can be tailored to needs; already in organic form vines can use = more readily available
○ Considerations - no benefit to organisms and do not improve soil structure; more expensive to buy, but much cheaper to transport and spread

Question 13

Nutrient Management

What are the 5 main methods of weed control?
what are 4 general buckets of pros/cons to think about in assessing them?

Answer 13

Cultivation
Herbicides
Animal grazing
Cover crops
Mulching

Pro/cons
* cost
* chemical use
* soil health impact
* vigor from reduced competition

Question 14

Nutrient Management

What is cultivation and what are benefits/considerations?

Answer 14

○ Method of weed control that involves plowing soil to cut or disrupt weeds root systems
○ Advantage - no chems used -> can be used in OV and BV; enables fert and cover crops to be incorp into soil at the same time as removing weeds
○ Disadv - repeated cultivation can damage soil structure due to breakdown of organic matter and impacting earthworm habitat; costly - machines and labor; buries weed seeds, allowing re-growth; can increase vine vigor too much since no competition for water/nutrients (not bad in low vigor sites), can increase spread of soil-borne diseases

Question 15

Nutrient Management

What are herbicides, what are the 3 types and what are benefits/consideration?

Answer 15

Herbicides are chemical sprays to kill weeds
3 types:
§ Pre-emergence - sprayed before weeds estab, stay in top layers of soil and absorbed by weeds roots and inhibit germination of seedlings
§ Contact herbicides - sprayed on estab weeds and kill green parts killing it
§ Systemic herbicides - sprayed on estab weeds; taken in by leaves and travel thru whole weed in the sap killing plant

		§ Benefits - cheap in labor and machinery needs, highly effective, less damaging to soil structure vs cultivation
		§ Disadvantages - poison risk to operator/consumer/environ and does not help ecosystem; weeds can become resistant req higher doses; increase vine vigor too much by reducing competition; not allowed in OV or BV

Question 16

Nutrient Management

What is animal grazing, what are benefits/considerations?

Answer 16

○ Allow animals (eg sheep) to graze in vineyard
○ Adv - no chems used, so allowed in OV and BV; animals add manure; animals source of meat for people
○ Disadv - Vines must be trained high enough (or grazing done outside growing season) or animals eat vine leaves/berries; labor - animals require care; animals susceptible to pesticides

Question 17

Nutrient Management

What are cover crops and why are they grown?

Answer 17

○ Plants specifically planted/allowed to grow that have benefit for vineyard
○ Can be done for weed mgt, improve soil structure, add competition with vine for water/nutrients in fertile sites, enhance bio diversity, provide driving surface

Question 18

Nutrient Management

What kind of cover crops are best and examples?

Answer 18

○ Those that are quick to establish and are adapted to respective soil/climate - legumes (beans/clover) and cereals (ryegrass, oats)
○ Can be bought from around the world, but have to be matched to needs of vineyard
○ Can allow natural vegetation to grow - cheap and can inc diversity, but doesn’t allow as much control as when cover crops chosen

Question 19

Nutrient Management

what are benefits/considerations of cover crops?

Answer 19

○ Adv - no chems and inc soil biological activity = common in OV and BV; ability to affect vine vigor by adding competition; good surface for machinery (esp in areas with high rain); can be turned into the soil adding organic matter (green manure)
○ Disadv - Can overly reduce vine vigor in poor soil/dry areas; time/labor - can be hard to mow under-row area; not suitable for steep sites (slippery when wet)

Question 20

Nutrient Management

What is mulching and what are benefits/considerations?

Answer 20

○ Spreading of matter onto soil to suppress weed growth; usually biodegradable material like bark or straw
○ Adv - no chems - common in OV and BV; can reduce water evap -> good in dry areas; promote soil bio activity and soil structure as a source of nutrients and humus as they break down
○ Disadv - expensive to transport/spread - bulky; only effective in thick layer, so a lot is needed; increase vigor too much if no other competitioon

Question 21

Water Management

What are 2 main components of water management?

Answer 21

Irrigation/water sourcing
Drainage

Question 22

Water Management

What are 5 main considerations for water management?

distinct from drainage

Answer 22

Natural water availability
Water laws
Sustainable practices
Water quality
Type, amount and timing of irrigation

Question 23

Water Management

What are examples of ways in vineyard water can be used more efficiently/sustainably?

Answer 23

○ Water efficient irrigation systems combined with monitoring of water uptake by vines
○ Use of drought-tolerant varieties (Grenache) and rootstocks (140R)
○ Reducing evaporation - mulching
○ Reduce competition - weeding
○ Increase humus to improve water retention by adding organic matter like compost
○ Promote growth of vine roots deep in soil - cultivation

Question 24

Water Management

How does qater quality affect the vineyard?

Answer 24

○ Water with a lot of dissolved solids (mud) - can block sprinklers/drip irrigation -> needs settling/filtering before use
○ High saline level (Australia) - increases salt in soil - harder for vine roots to take up water -> vine becomes dehydrated -> green parts wilt and vine starts to die – especially an issue with drip irrigation as salt accumulates at root zone vs going deeper in soil (flood irrigation)

Question 25

# Water Management What are the 4 types of irrigation? What are main considerations for which type used?

Answer 25

Drip, Flood, Channel, Overhead sprinkler Considerations: ○ Amount of water available ○ Amount of water needing to be applied ○ How targeted water application needs to be ○ Cost of establishment and maintenance

Question 26

# Water Management What is most common type of irrigation

Answer 26

Drip irrigation by far most common

Question 27

# Water Management What is drip irrigation and what are benefits/considerations?

Answer 27

○ Narrow water pipes laid along each row, usually along lowest trellis wire. Drippers put at intervals, far enough from vines to encourage roots to grow and seek water (otherwise vines will stay close to trunk where water is) ○ Benefits - economic use of water; allows for tailored water application by row/block as needed to manage yield/quality; can also supply fert (fertigation); can be used on slopes ○ Disadv - installation costs high, but moderate maintenance costs; clean water required; drippers can get blocked over time = labor; cannot be used in frost protection since they are below green part of vine

Question 28

# Water Management What is flood irrigation and what are benefits/considerations?

Answer 28

○ Water held behind sluice and released at scheduled time to flood vineyard ○ Adv - cheap to install and maintain ○ Disadv - very inefficient as a lot of water not used by vines; only good on flat sites

Question 29

# Water Management What is channel irrigation and what are benefits/considerations?

Answer 29

○ Water flows in furrows dug between vine rows ○ Adv/disadv - more efficient than flood; can only use on flat sites ○ Common in Argentina - lots of water from Andes

Question 30

# Water Management What is overhead sprinkler irrigation and what are benefits/considerations?

Answer 30

○ Pump water and shower over vineyard ○ Adv/disadv - can be used for frost protection; expensive to install and maintain (need high water pressure) and use relatively large amt of water vs drip

Question 31

# Water Management What is RDI, where best used and what are benefits/considerations?

Answer 31

RDI = redulated deficit irrigation ○ system of timing and regulating amt of irrigation so vine has scheduled periods of mild water stress during appropriate times of vine cycle; mild water stress usually set between fruit set and veraison -> limit shoot growth, encourage grape dev ○ Usually use drip system ○ Best used in dry growing season w/ sandy or loamy soil that dry out and can be re-wetted quickly -> much harder in areas with frequent rain in growing season and areas with heavy clay soil (take a long time to dry out) ○ Benefits - better control of vine growth and grape dev; uses less water; often favored for black grapes as berries often smaller - inc prop of skin to juice => higher concentration of anthos and tannins = quality ○ Considerations - timing of water application and monitoring of soil water levels crucial. Too much water stress or at wrong time = reduction of yield and quality; often results in lower yields in general => grower must feel quality improvement offsets yield loss; additional costs to monitor equipment and respond to soil moisture levels

Question 32

# Water Management When is water best applied/withheld during vine growth cycle?

Answer 32

○ Plentiful water during spring encourages leaf and shoot growth ○ Moderate water stress bet fruit set and veraison beneficial - to stop shoot growth and encourage grape development/ripening

Question 33

# Water Management What is dry farming?

Answer 33

○ Growers do not use any irrigation - either by law or by choice - in areas where there is limited rain in growing season ○ Can result in lower yields, but higher quality

Question 34

# Water Management Why is drainage an important consideration for water management?

Answer 34

○ If soils not free-draining in rainy areas -> causes numerous problems (see ch 8 - disease/pest) ○ Aids mechanization

Question 35

# Water Management What can growers do to affect drainage?

Answer 35

○ Install artificial drainage systems - only before vineyard established -> cost of installing often offset by having better, healthier, better balanced vines and consistent ability to ripen grapes In high rainfall areas - growers can leave natural vegetation or plant crops to add water competition; improve soil structure and remove any plow pans to better regulate water drainage