Nutrients Flashcards
Where does the vine acquire its nutrients?
Soil
What factors do nutrients influence?
- vine heatlh
- grape yield
- grape composition
Do vines require high or low levels of nutrients?
low
What are the 5 most important nutrients for vines?
- Nitrogen
- Potassium
- Phosphorus
- Calcium
- Magnesium
What is nitrogen essential for?
- vine growth
- major impact on vine vigor and grape quality
- component of chlorophyll (required for photosynthesis)
What happens if there is too much nitrogen in the soil?
Excessive vegetative growth
- sugars diverted to the growing shoots and leaves rather than the grapes, hindering ripening
- poor ventilation (leading to fungal disease) unless adequately managed
What happens if there is too little Nitrogen in the soil?
- reduced vigor
- yellowing of vine leaves
- problematic for fermentation
What is Potassium essential for?
- vine growth
- regulates the flow of water in the vine
What happens if there is too much potassium in the soil?
= problems in the uptake of magnesium, which may lead to reduced yields and poor ripening
- leads to high potassium levels within the grapes (wine quality lowers, as high levels of potassium in the grape must are linked to high pH)
What happens if there is too little potassium in the soil?
- low sugar accumulation in the grapes
- reduced yields
- poor vine growth in general
What is phosphorus essential for?
- photosynthesis
What happens if there is too little phosphorus in the soil?
Vines need only a small amount, usually there is enough in the soil
What is calcium essential for?
- structure of plant cells
- photosynthesis
What happens if there is too little calcium in the soil?
- negative influence on fruit set
What is magnesium essential for?
- magnesium is found in chlorophyll
- key role in photosynthesis
What happens if there is too little magnesium in the soil?
- reduced grape yields
- poor ripening
What affects nutrient availability in soil?
soil pH
What is chlorosis? What causes it?
- this is a condition in which leaves turn yellow and photosynthesis stops, so grape ripening and yields are negatively affected as a result
- lack of available iron in the soil (high pH)
What must happen before the vine can take up organic nutrient compounds (found in and added to the soils)?
- need to be converted into inorganic compounds
- organisms that live in the soil feed on the organic matter and convert it for the vine
What is mineralization?
The process by which organism that live in the soil ( such as bacteria, fungi, earthworms, etc) feed on the organic matter and convert it into available forms
What types of soil texture are good at holding nutrients? Bad?
- good: clay
- bad: sandy
What can increase the soil’s ability to hold nutrients?
Humus
What soils are typically less fertile and thinner: soils on slopes, or soils on plains/valley floors?
slopes
What is soil? What is it comprised of?
- soil is the upper layer of the earth
- typically made up of geological sediment, organic remains in the form of humus, and the pores in between the sediment that contain water and air
Where does the sediment come from?
Sediment comes from the weather of bedrock (solid rock)
What types of layers make up the soil of a particular vineyard site?
- different layers formed at different periods of time, each of which may have a different texture, structure, and characteristics
- the sediment in the soil may not be the same as the bedrock underneath; for example, over time the sediment may have been transported by water, winds, glaciers, or gravity (down-slope)
What are the two main functions of soil?
- supports the vines’ roots
- medium from which vines take up water and nutrients
Describe clay soil. How does this affect its ability to hold water and nutrients?
- finely-textured
- very small particles (larger surface area compared to their volume)
- very effective at holding water and nutrients
Describe sandy soil. Describe how these characteristics affect the soil’s ability to hold water and nutrients.
- loosely-textured
- relatively large particles with small surface area compared to their volume
- limited capacity to hold water
- easy drainage
- poor at retaining nutrients
- workable and easy for vine roots to grow through
Describe silt soil.
Silt has particles of intermediate size and its properties sit between that of clay and sad.
What is loam soil? Describe its characteristics when it comes to drainage and water/nutrient holding capacity.
- loam describes a soil that has moderate proportions of clay, silt, and sand
- may contain a proportion of larger rock fragments, such as gravel or pebbles (larger than gravel)
- good drainage
- lower water and nutrient-holding capacity
What is soil texture?
The texture of the soil describes the proportions of the mineral particles of sand, silt and clay
What is soil structure?
- the structure of the soil describes how the mineral particles in the soil form aggregates (crumbs)
- the size, shape, and stability of these aggregates are also important for determining water drainage, root growth, and workability of the soil
Describe the soil structure of soils that have a very high clay content
- sticky
- may for aggregates that are hard for vine roots to penetrate and challenging for soil cultivation
- the vines’ roots may be limited to cracks or gaps between the aggregates
Describe the structure of soils that are high in sand or larger particles such as gravels or pebbles
- very loosely structured
- need some clay to help bind them together
- humus helps to bind soils together, and can help retain water and nutrients
What is humus? What’s its texture? What does it help with?
- organic matter in the soil that is formed by the partial decomposition of plant material by soil microbes and earthworms
- has a spongey texture, large surface area, and is able to adsorb water and nutrients
What does the suitability of the soil for viticulture depend on?
- soil texture
- soil structure
- how far the roots are able to penetrate
- climate suitability
