Ch. 6 Managing Nutrients and Water Flashcards
Describe soil health. How is it monitored?
The continued capacity of the soil to act as a living ecosystem that supports humans, plants and animals.
Related to:
- structure of soil - drainage, water-holding capacity, O2, resist erosion, can vines penetrate to enough depth
- amount of organic matter and humus in soil - for nutrients, humus improves structure and water-holding capacity
- number of living organisms in soil - earthworms, microbes break down organic matter into humus and inorganic nutrients that the vine can absorb
- amount of available nutrients
Grape growers monitor soil health through soil tests - when establishing vineyard and then annually.
Considerations for nutrient management.
Most imp ones are nitrogen, phosphorus and potassium.
They need to be in inorganic form so they can be absorbed by the vine
Why would a grape grower remove weeds?
Less competition for nutrients and water
Bare moist soils are best at absorbing heat during the day; heat they release at night reduces frost risk
Weeds also block passage of machinery and personnel
Weeds increase frost risk
Describe the difference between organic and inorganic fertilisers. Considerations for fertiliser use.
Both added before planting to help growth of young vines
Balance is key - too much will lead to excess vigour which will increase shading of bunches or uneven ripening during ripening if vine still focused on growing
Organic fertilisers - derived from fresh or composted animal or plant material (like manure or slurry); cover crops can be turned into soil to decompose and provide nutrients (green manure)
Adv
- cheap, even free
- high in humus, so help with soil structure and water retention
- nutrients can also be absorbed by living organisms in soil
- Gradual incorporation into soil
Dis
- Need to be incorporated into soil, which requires lavor
- Bulky, expensive to transport and spread
Inorganic fertilisers (synthetic, mineral)
- Manufactured from minerals extracted from ground
Adv
- More tailored, customized (can provide single or several nutrients)
- Nutrients more readily available to vines
- Less bulky, cheaper to transport and distribute
Dis
- No benefit to organisms or soil structure
- More expensive to purchase
Describe the difference between organic and inorganic fertilisers. Considerations for fertiliser use.
Both added before planting to help growth of young vines
Balance is key - too much will lead to excess vigour which will increase shading of bunches or uneven ripening during ripening if vine still focused on growing
Organic fertilisers - derived from fresh or composted animal or plant material (like manure or slurry); cover crops can be turned into soil to decompose and provide nutrients (green manure)
Adv
- cheap, even free
- high in humus, so help with soil structure and water retention
- nutrients can also be absorbed by living organisms in soil
- Gradual incorporation into soil
Dis
- Need to be incorporated into soil, which requires lavor
- Bulky, expensive to transport and spread
Inorganic fertilisers (synthetic, mineral)
- Manufactured from minerals extracted from ground
Adv
- More tailored, customized (can provide single or several nutrients)
- Nutrients more readily available to vines
- Less bulky, cheaper to transport and distribute
Dis
- No benefit to organisms or soil structure
- More expensive to purchase
Define cultivation and describe its advantages and disadvantages.
- A. method of weed control that involves ploughing the soil to cut or disturb the weeds’ root systems
ADV
- No chemicals - suitable for biodynamic or organic
- You can also add fertiliser and mown cover crops into the soil at the same time as you remove the weeds
DIS
- Can damage soil structure and ecology - constantly breaking down organic matter, disrupting earthworms and habitat
- Costly - requires skilled labor and machinery
- Moving soil around buries seeds, encouraging weeds to grow back
- No competition from weeds for water or nutrients so it can increase vine vigor (not a bad thing in sites w poor soils or lack of water)
Define herbicides and describe their advantages and disadvantages
Chemical sprays that kill weeds. 3 types are
- Pre-emergence, before weeds establish
- Contact, sprayed on established weeds, kill green parts
- Systemic herbicides, sprayed on weeds and taken in by leaves, kills whole plant
ADV
- cheap in terms of labor and machinery requirements
- highly effective, particularly in under-row
- less damaging to soil structure than cultivation
DIS
- risk of poisoning operator, consumer, environment
- Weeds can become resistant, more herbicides needed
- Increase vine vigor, no competition from weeds
- Not allowed in organic, biodynamic viticulture
Describe animal grazing and its advantages/disadvantages.
Allowing animals, such as sheep, to graze in the vineyard as weed control.
ADV
- No chemicals, acceptable for biodynamic and organic viticulture
- Animals provide manure
- Animals source of meat (?)
DIS
- Vines trained high, otherwise risk of animals eating grapes and leaves off vines
- Labor required to care for animals
- Susceptible to vineyard pesticides, can die
Describe the practice of using cover crops in a vineyard.
Cover crops are plants that are specifically planted or allowed to grow to benefit the vineyard in various ways. They can:
- suppress weeds
- improve soil structure
- compete with vine for nutrient + water in fertile sites
- curb soil erosion
- enhance biodiversity
- surface to drive on
Ex - legumes, cereals –> need to be matched to needs of vineyard (think of Angludet - apple orchard with bats to eat insects)
the more precise the better - know which characteristics will benefit your vineyard and its needs/challenges
Need balance and maintenance –> can’t be left wild otherwise will compete w vine too much for resources
ADV
- no chemicals, increases soil biological activity and biodiversity in vineyard, commonly used in org and biod viticulture
- Influence vigor of vine thru competition
- Good surface for machinery
DIS
- reduction in vine vigor that can be excessive in poor soils and dry environments
- harder to mow under-row area, takes more time/labor
- Unsuitable for steeply sloping vineyards
Describe the practice of mulching, it’s advantages and disadvantages
- The spreading of matter into the vineyard soil to suppress the growth of weeds. Usually made of biodegradable materials such as straw or bark chips, that ultimately provide nutrients for vines.
ADV
- no chemicals, suitable for org, bio vineyards
- reduce water evaporation from soil, helps dry climates**
- good source of nutrients and humus, helps soil bio activity and structure
DIS
- bulky, expensive to transport and spread
- need a thick layer, only effective if used in large quanitiy
- can increase vigor too much (not bad thing in low vigor sites)
What are considerations regarding irrigation?
- needs to be part of vineyard design and establishment in areas that receive little water throughout growing season or have very free-draining soils
- some EU GI’s do not permit irrigiation or only allow it in emergency situations
- water can come from many sources like nearby river, lake, reservoir or bore hole
What steps can be taken to increase efficiency of water use, especially in countries like Australia, Cali or SA where prolonged periods of dry weather have caused shortages in water supply?
- water-efficient irrignation systems, careful monitoring of water absorption by vines
- use of drought-tolerant grape varieties (Grenache) and rootstocks (140R)
- Reducing evaporation (mulch)
- Reducing competition (removing weeds)
- Increasing humus levels in soil to improve water retention (org matter such as compost)
- Promoting growth of vine roots deep into soil
- re-using water from winery and vice-versa
What should a grape grower consider regarding water quality?
- water w high amount of dissolved solids like mud can block sprinkler and drip systems
- high levels of salt in water can dehydrate vine - esp w drip irrigation where salt accumulates at the root
What are the advantages and disadvantages of drip irrigation systems?
- most common
ADV
- economic use of water
- possible to control water supply to individual rows or blocks - customized management, potential for higher yields and quality
- systems can also supply fertilisers
- can be used on slopes
DIS
- Installation costs are high (maintentance costs moderate)
- Clean water required, otherwise drippers get blocked
- Some maintenance work required to unblock even if not often
- Drippers below green parts of vine closer so can’t be used for frost protection
What are the advantages and disadvantages of flood irrigation systems?
- water floods vineyard at scheduled time
ADV - cheap to install and maintaing DIS - inefficient, a lot of water not taken up - only on flat or gently sloping land
