Plants water&soil

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Plants & Water Plants contain large amounts of water. Most herbaceous parts of plants are over

80% water.

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Plants use water for several purposes

Photosynthesis: For each molecule of glucose made by plants, 6 or more molecules of water must be broken apart.

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Plants use water for several purposes

Turgor: The abundant presence of water in the cell stiffens the herbaceous parts of the plant.

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Plants use water for several purposes

Hydrolysis: Plants often break apart large molecules by adding water molecules or parts of water molecules.

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Plants use water for several

purposes

Translocation: The materials in a plant can be moved only if they are dissolved in water.

Clay, loess & loam - what is good

soil ?

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Soil

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Soil is the unconsolidated mineral material on the immediate surface of the Earth that serves as a natural medium for the growth of land plants.

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composition of soil by volume

Ideal fertile soil Mineral 45% Organic matter 5% Water 25% Air 25%

http://jpkc.snnu.edu.cn/geog/webasp/kj/kejian/6%20turangquan.ppt

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soil particle

Sizemm

Minerals (%)

SiO2 Al2O3 Fe2O3 CaO MgO K2O Na2O P2O5

1~0.2 83.92 9.34 1.12 1.79 0.38 1.78 1.21 0.08

0.2~0.04 73.87 13.47 4.21 3.05 1.05 1.73 1.53 0.12

0.04~0.01 70.15 14.04 5.86 2.15 1.05 1.48 3.89 0.21

0.01~0.002 67.21 18.91 7.85 1.45 1.63 2.51 1.27 0.29

<0.002 44.08 27.67 21.81 0.58 1.61 1.10 0.96 0.36

The larger the particles are, the more SiO2 the soil has, the more barren it is.

http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/2.1.ppt

12http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/2.1.ppt

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http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/2.1.ppt

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Soil types Soil texture

clay clay

loesssilt, with small amount of clay and sand

loam sand, silt, clay

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Clay

Mineral: Al2[(OH)4Si2O5] · nH2O

Al2O3 · 2SiO2 · 2H2O etc.

poor aeration and drainage

plastic when wet, when dry become firm

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Clay is only good for paddy rice fields.

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loess

Mineral: most carbonates

small amount of clay minerals

good aeration, water-holding ability

easy to be transported by river and wind

for example: 1935 dust storm in midwest United States

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loam

mixture of clay, silt and sand sandy, plastic when wet easily water contain more nutrients than sandy soils ideal fertile soil

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soil pH value

The chemistry of plant elements in the soil can be affected by pH.

Soil pH is the measurement of acidity (sourness) and alkalinity (sweetness).

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If the soil pH is acid, or extremely low, some micronutrients become too soluble and occur in concentrations great enough to harm plant.

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If soil pH is high, in the alkaline range, many of the nutrients can be precipitated out and not be available to plants.

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The best pH value for plants is 6,5 .

in soil pH in soil pH

Na2CO3

NaHCO3

MgCO3

CaCO3 CaCO3-withCO2

Ca(HCO3)2

12~138.5~9.511.4710.208.48

6.13~8.4

CaSO4

H2O

Na2SO4， MgSO4， NaCl， MgCl2

NH4ClH2CO3

KAl(SO4)2； AlCl3

7.07.7~7.1

6.3~6.5~6.84.7

3.9~5.72~4

soil pH value

http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt

27http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt

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FruitPLANT TYPE SOIL pH

Apple 5.0-6.5

Apricot 6.0-7.0

Arbor Vitae 6.0-7.5

Blueberry, high bush 4.0-5.0

Cherry, sour 6.0-7.0

Cherry, sweet 6.0-7.5

Crab apple 6.0-7.5

Cranberry, large 4.2-5.0

Peach 6.0-7.5

Pineapple 5.0-6.0

Raspberry, red 5.5-7.0

Strawberry 5.0-6.5

http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt

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VegetablesPLANT TYPE SOIL pH

Asparagus 6.0-8.0

Beets, table 6.0-7.5

Broccoli 6.0-7.0

Cabbage 6.0-7.5

Carrot 5.5-7.0

Cauliflower 5.5-7.5

Celery 5.8-7.0

Cucumber 5.5-7.0

Lettuce 6.0-7.0

Muskmelon 6.0-7.0

Onion 5.8-7.0

Potato 4.8-6.5

Rhubarb 5.5-7.0

Spinach 6.0-7.5

Tomato 5.5-7.5 http://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt

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Summary

Clay: perfect water-holding ability good for paddy rice fields. Both loess and loam can be tillable soil for

most of plants. But loam is better, because of more

nutrients. more than 1.5% organic matter pH value by 6.5

Different soil types develop in Different soil types develop in different climates.different climates.

Soils-4-1Image: T. Loynachan

Prairie soils have a dark surface layer Prairie soils have a dark surface layer (horizon), are rich in minerals, and form in (horizon), are rich in minerals, and form in

grasslands widespread across Earth’s grasslands widespread across Earth’s middle latitudes.middle latitudes.

Soils-4-2

Images: NRCS

Forest soils have a light gray upper Forest soils have a light gray upper horizon, a horizon rich in aluminum horizon, a horizon rich in aluminum

and/or iron, and form in warm to cool and/or iron, and form in warm to cool humid regions where coniferous forests humid regions where coniferous forests

grow.grow.

Image: Soil Classifiers of Michigan

Tropical soils are reddish and iron-oxide Tropical soils are reddish and iron-oxide rich, depleted in nutrients, and form in rich, depleted in nutrients, and form in

humid and warm regions.humid and warm regions.

Soils-4-4Images: National Cooperative Soil Survey, University of Nebraska

Organic soils are dark colored, rich in Organic soils are dark colored, rich in decomposed organic matter, and form in decomposed organic matter, and form in poorly drained lowlands such as swamps poorly drained lowlands such as swamps

and wetlands.and wetlands.

Soils-4-5Images: Bruce Molnia, Soil Classifiers of Michigan

Desert soils form in arid settings and are Desert soils form in arid settings and are commonly rich in calcium carbonate.commonly rich in calcium carbonate.

Images: Martin Miller, NRCS

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Tundra soils form in Arctic environments, Tundra soils form in Arctic environments, have a dark organic-rich upper layer, and a have a dark organic-rich upper layer, and a

mineral rich layer over frozen ground.mineral rich layer over frozen ground.

Soils-4-7Images: Travis Hudson, Alaska/Yukon Society of Professional Soil Scientists