50 60 70 80 90 100 110 120 130 140 1500

50

100

150

200

250

300

350

70.5170

Index value

Fre

quen

cy

Soil and mineral nutrition

• Soil is a complex product of the interaction between living organisms and their terrestrial environment

• Soils are very heterogeneous • Soil texture describes the relative

contribution of particle with different sizes that impart different characteristics and affect plant performance

• Most plants depend on soil to obtain water and mineral nutrition

• The pH of soil is an important characteristic that affects nutrient intake

• Essential nutrients are indispensable for plant growth and reproduction

• Most plants depend on mycorrhizae (symbiotic relationships with fungi) to increase phosphorus and other minerals from the soil

taproot

Fibrous root

enlarging radicle, or embryonic root

Adventitious roots (develop from stems)

Stem x.s. of Lycopersicon (tomato)

http://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10

Contain suberin, a fatty waterproof material

Water enters by osmosis

Nutrient minerals enter by passing through carrier proteins in the membranes

http://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10

Root x.s. of Zea mays (corn)

Epidermis

Cortex cell

Endodermis

Pericycle cell

Pith cell

Xylem vessel element

Phloem cell

Soil is composed of

• Inorganic mineral particles

• Organic matter

• Water

• Air

The texture, or structural characteristic of a soil is determined by the percentages (by weight) of the different-sized inorganic mineral particles -sand (0.02-2 mm), silt (0.002-0.02 mm), and clay (<0.002 mm), -

A loam: 40 % sand, 40 % silt, and 20 % clay

Igneous rocks

http://cmsc.minotstateu.edu/Labs/rockslab/igneous/igneousbox.html

Metamorphic rocks

http://cmsc.minotstateu.edu/Labs/rockslab/metamorphic/metamorphicbox.html

Sedimentary rocks

http://cmsc.minotstateu.edu/Labs/rockslab/sedimentary/sedimentarybox.html

0 100

Kilometers

25 50 75

Pre-SettlementSoils

ExtantHabitats

This map was created at theArchbold Biological StationGeographic InformationSystem Laboratory.

Prepared by:Roberta L. Pickert.9 December 1999www.archbold-station.org

N

ArchboldSt. Lucie

AstatulaCandler

LakeOrsinoPaola

Tavares

Satellite

White Sands

Yellow Sands

Grey Sands

0 50 100 kmRoberta Pickert 1999

Elements required by plants(macronutrients, >0.05% dry weight)

Carbon CO2 carbohydrates ,lipids, proteins and nucleic acids

Hydrogen H2O carbohydrates ,lipids, proteins and nucleic acids

Oxygen H2O, CO2 carbohydrates ,lipids, proteins and nucleic acids

Nitrogen NO3, NH4 proteins, nucleic acids, and chlorophyll

Potassium K osmotic and ionic balance

Calcium Ca2 in cell walls; membrane permeability

Magnesium Mg2chlorophyll;

Phosphorus HPO42,

H2PO4

nucleic acids, ATP, phospholipids

Sulfur SO42 Aminoacids

Silicon SiO32

in cell walls Table 34-2 pp. 744

Elements required by plants(micronutrients, <0.05% dry weight)

• Chlorine, Iron, Boron, Manganese, Sodium, Zinc, Copper, Nickel, Molybdenum

• Parts of enzymes and Ionic balance.

Table 34-2 pp. 744

Plant proteins Animal proteins

Nitrogen wastes

Ammonium NH4

Ammonia

Loss to Atmosphere

Nitrites, NO2

Nitrates, NO3

Nitrogen fixing bacteria, Azotobacter (ae) and Clostridium (an)

Gain from

atmosphere

Nitrifying bacteria

Denitrifying bacteria

e.g. Nitrobacter

Denitrifying bacteria

e.g. Nitrosomonas

Decay bacteria and Fungi

The Nitrogen Cycle

Endophytes:Legume/Rhizobium nodules

http://www.botany.hawaii.edu/faculty/webb/BOT410/Roots/RootSymbioses.htm

Leghaemoglobin sequesters oxygen and creates a low oxygen environment

Above: EctomycorrhyzaeBelow: EndomycorrhyzaeMOORE-LANDECKER. 1990. FUNDAMENTALS OF THE FUNGI. PRENTICE HALL.

ENGLEWOOD CLIFFS. Pp. 481, fig. 15-9; 483, fig. 15-10

Occurs in 90 % of all plant families

Total mass (g) of mycorrhyzae present absent

Andropogon gerardii 89 66

Sorghastrum nutans 121 62Wilson and Hartnett. American Journal of Botany 84 No, 4, 1997

Arbuscular Mycorrhizae

http://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10

Cross-section of Ranunculus root (buttercup)

immature

Mature

epidermis

stelecortex

Notice numerous amyloplasts which store starch

Close up of Cross-section of Ranunculus root

immature

Maturehttp://www.uri.edu/artsci/bio/plant_anatomy/images.html#lab_10

Cortex cells

Endodermis cells

Pericycle cells

Phloem cells

Xylem vessel element

Intercellular spaces

Cation exchange

Neutral pH near 7

Acid pH, 4-5