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Plants & WaterPlants contain large amounts of water. Most herbaceous parts of plants are over 80% water.
Plants use water for several purposesPhotosynthesis: For each molecule of glucose made by plants, 6 or more molecules of water must be broken apart.
Plants use water for several purposesTurgor: The abundant presence of water in the cell stiffens the herbaceous parts of the plant.
Plants use water for several purposesHydrolysis: Plants often break apart large molecules by adding water molecules or parts of water molecules. *
Plants use water for several purposesTranslocation: The materials in a plant can be moved only if they are dissolved in water.
Clay, loess & loam - what is good soil ?
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.
composition of soil by volumeIdeal fertile soilMineral 45%Organic matter 5%Water 25%Air 25%http://jpkc.snnu.edu.cn/geog/webasp/kj/kejian/6%20turangquan.ppt
soil particleThe 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
Soil typesSoil textureclayclayloesssilt, with small amount of clay and sandloamsand, silt, clay
ClayMineral: Al2[(OH)4Si2O5] nH2O Al2O3 2SiO2 2H2O etc.
poor aeration and drainage
plastic when wet, when dry become firm
Clay is only good for paddy rice fields.
loessMineral: 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
loammixture of clay, silt and sandsandy, plastic when weteasily water containmore nutrients than sandy soils ideal fertile soil
soil pH valueThe chemistry of plant elements in the soil can be affected by pH.Soil pH is the measurement of acidity (sourness) and alkalinity (sweetness).
If the soil pH is acid, or extremely low, some micronutrients become too soluble and occur in concentrations great enough to harm plant.
If soil pH is high, in the alkaline range, many of the nutrients can be precipitated out and not be available to plants.
The best pH value for plants is 6,5 .soil pH valuehttp://netc.nwsuaf.edu.cn/jingpin/2003/turangxue/ppt/5.1.ppt
in soilpHin soilpHNa2CO3NaHCO3MgCO3CaCO3 CaCO3-withCO2Ca(HCO3)212~138.5~9.511.4710.208.486.13~8.4CaSO4H2ONa2SO4MgSO4NaClMgCl2NH4ClH2CO3KAl(SO4)2AlCl37.07.7~7.16.3~6.5~126.96.36.199~5.72~4
PLANT TYPESOIL pH Apple 5.0-6.5Apricot 6.0-7.0Arbor Vitae 6.0-7.5Blueberry, high bush 4.0-5.0Cherry, sour 6.0-7.0Cherry, sweet 6.0-7.5 Crab apple 6.0-7.5 Cranberry, large 4.2-5.0Peach 6.0-7.5Pineapple 5.0-6.0Raspberry, red 5.5-7.0Strawberry 5.0-6.5
PLANT TYPESOIL pH Asparagus 6.0-8.0Beets, table 6.0-7.5Broccoli 6.0-7.0Cabbage 6.0-7.5 Carrot 5.5-7.0 Cauliflower 5.5-7.5Celery 5.8-7.0Cucumber 5.5-7.0Lettuce6.0-7.0Muskmelon 6.0-7.0 Onion 5.8-7.0 Potato 4.8-6.5 Rhubarb 5.5-7.0Spinach 6.0-7.5Tomato 5.5-7.5
SummaryClay: 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 matterpH value by 6.5
Different soil types develop in different climates.Soils-4-1Image: T. Loynachan
Prairie soils have a dark surface layer (horizon), are rich in minerals, and form in grasslands widespread across Earths middle latitudes.Soils-4-2Images: NRCS
Forest soils have a light gray upper horizon, a horizon rich in aluminum and/or iron, and form in warm to cool humid regions where coniferous forests grow.Image: Soil Classifiers of Michigan
Tropical soils are reddish and iron-oxide rich, depleted in nutrients, and form in humid and warm regions.Soils-4-4Images: National Cooperative Soil Survey, University of Nebraska
Organic soils are dark colored, rich in decomposed organic matter, and form in poorly drained lowlands such as swamps and wetlands.Soils-4-5Images: Bruce Molnia, Soil Classifiers of Michigan
Desert soils form in arid settings and are commonly rich in calcium carbonate.Images: Martin Miller, NRCS
Tundra soils form in Arctic environments, have a dark organic-rich upper layer, and a mineral rich layer over frozen ground.Soils-4-7Images: Travis Hudson, Alaska/Yukon Society of Professional Soil Scientists