SOIL FERTILITYSOIL FERTILITYINTRO TO SOILS

CH 10

SOIL FERTILITYSOIL FERTILITY

Ability of soil to supply nutrients for plant growth

Readily Available – soil solutionNot Readily Available – mineral particles

Important Concepts:- quantity of nutrients- protection from leaching- availability- ease of root access

SOIL FERTILITYSOIL FERTILITY

Essential Elements* needed for plant growth

* 18 elements identified as essential for plants

- essential elements used in large amounts are called macronutrients

- essential elements used in smaller amounts are called micronutrients

SOIL FERTILITYSOIL FERTILITY

Three (3) nutrients are obtained fromair and water:

C, O, H

The other nutrients are obtained from the soil as ions(see fig. 9-1) except Boron (H3BO3) as Boric Acid

NUTRIENT IONSNUTRIENT IONS

Ions are simply charged atoms or molecules . . .

Cations are positive (+)Anions are negative (-)

Charges result from difference in number of protons and electrons

Plant roots absorb nutrient ions . . .

Soil particles adsorb nutrient ions

Sources of Elements in SoilSources of Elements in Soil

Four Sources: (fig. 10-4, p.159)

Soil MineralsOrganic Matter

Adsorbed NutrientsDissolved Ions

http://syllabus.syr.edu/esf/rdbriggs/for345/cation.htm