SOIL FERTILITY INTRO TO SOILS CH 10

SOIL FERTILITY Ability of soil to supply nutrients for plant growth Readily Available – soil solution Not Readily Available – mineral particles Important Concepts: - quantity of nutrients - protection from leaching - availability - ease of root access

SOIL 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 FERTILITY Three (3) nutrients are obtained from air and water: C, O, H The other nutrients are obtained from the soil as ions (see fig. 9-1) except Boron (H 3 BO 3 ) as Boric Acid

NUTRIENT 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 Soil Four Sources:(fig. 10-4, p.159) Soil Minerals Organic Matter Adsorbed Nutrients Dissolved Ions

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