D1: growing environment nutrients 6 Flashcards
Nutrients are important for healthy vine growth and can have an influence on yield and grape composition.
1) vine require low lvl of nutrients (so most soils are able to sustain vine growth)
2) soil nutrients are depleted (uitgeput) by viticulture, so monitoring is important before it leads to any deficiencies
The most important nutrients are:
1) nitrogen
2) Potassium
3) Phosphorus
4) Calcium
5) Magnesium
Nitrogen:
1) essential for vine growth (vigour and grape quality)
2) it is a component of proteins and chlorophyll (required for photosynthesis)
3) too much can cause excessive shoot growth
* sugars being diverted to the growing shoots and leaves rather than the grapes
* causes big canopy
4) low levels: reduces vigour and yellowing of vine leaves
*** good level result in high quality grapes
Potassium:
1) helps regulate the flow of water in the vine
2) very high levels can cause problems in the uptake of magnesium — reduced yields and poor ripening
3) high potassium in soil leads to high potassium levels in grape
* high potassium level in grape must are linked to high ph
4) low levels can lead to low sugar accumulation in the grapes, reduced grape yields and poor vine growth in general
Phosphorus:
1) important for photosynthesis
2) only a small amount needed, and enough present in soil usually
3) a deficiency leads to poorly developed root systems (and hence a diminished ability to take up water and nutrients
Calcium:
1) important role in the structure of plant cells and in photosynthesis
** deficiency is rare but have an negative influence on fruit set
Magnesium:
1) magnesium is found in chlorophyll and therefore has a key role in photosynthesis
** deficiency can result in reduced grape yields and poor ripening
Nutrients dissolve in soil water, which is then taken up by the roots of the vine so soil factors that influence water availability also impact nutrient availability:
true
Iron is poorly available in soils with high ph (soils with high proportion of calcium carbonate such as limestone and this can cause:
chlorosis
chlorosis:
Leaves turn yellow and photosynthesis stops
so graperipening and yields are negativelly affected
Organic nutrient compounds found and added to soils (eg in the form of manure or compost) are not available in the form that the vine can take up and need to be converted into inorganic compounds:
in this context organic matter contains carbon , inorganic generally describes compounds that do not contain carbon
Mineralisation:
Organisms that live in the soil (bacteria fungi eartworms,…) are important in this process
* feeding on the organic matter and converting it into available forms
** organic matter can be converted by these organisms into either humus or inorganic nutrient compounds
soil with high proportion of clay are good at holding nutrients, whereas sandy soils are poor at holding nutrients
Humus can increase the soila ability
Soils on slopes are often thinner and less fertile than those on plains or valley floors
true
Soil is the upper layer of earth and typically made of geological sediment,
Organic remains in the form of humus and the poors in between the sediment that contains water and air
Sediment:
comes from the weathering (verslijten, verweren) of bedrock (solid rock)
The soil in the vineyard can often be made up of 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 be not the same as the bedrock.
** this is due erosion by water, wind glaciers or gravity
In the context of the vineyard the soil support the vines roots and is the medium from which vines take up water and nutrients.
it is also the key habitat for the vineyard ecosystem supporting a number of animals and microbes.
there is a link about the chemical composition of the bedrock giving particular aromas to the wine.
true
Texture of the soil:
1) describes the proportions of the mineral particles of sand, silt and clay
* soil with a high proportion of clay are said to be finely textured as clay particles are small and because of this have a large surface area compared to their volume
2) Sand particles are relatively large and have a small surface area compared to thei volume
* limited water holding capacity as it easily drains away
* sandy soils have a loose texture, making them workable and easy for vines roots to grow through
3) silt has particles of intermediate size and its properties sit between clay and sand
4) loam describes a soil that had moderate proportions of clay, silt and sand
5) between the sand, silt and or clay there also can be larger rock fragments (gravel or pebbless– largger than gravel)
* these improve waterdrainage but lower water and nutrient holding capacity
structure of soil:
1) describes how the mineral particles in the soil for aggregates (crumbs)
* size, shape are also important determing water drainage root growth and workability of the soil
2) clay: sticky, hard for roots to penetrate and challenging for soil cultivation
3) sand, gravel and pebbles: loose structured and can need some clay to bind them together
humus:
organic matter in soil that is formed by partial decomposition of plant material by soil microbes and earthworms
- it has a spongy texture, large surface area and is able to absorb water and nutrients
- it helps to bind soils together and can help soils to retain water and nutrients
Te suitability of the soil for viticulture will depend on the structure and texture combined with how far the roots are able to penetrate:
Very sandy or stony soil have poor water and nutrient holding caacity, but may prove suitable if the vine roots are able to grow freely and deeply
— giving the vine a large area at which can obtain water
Climate and soil:
1) free draining soils can be benefical in rainy climates (gravely soils of haut medoc)
2) excess water can displace oxygen in the soil, and oxygen is essential for the respiration of vine roots and soil organisms
* * waterlogged soils can lead to reduced vine growth and eventually death of vine
There are several options that the vinegrower can take if the soil is not completely suitable:
1) poor nutrients: fertlizer can be applied
2) irrigation can be installed if the soil are too free-draining
