Dr. Bob Lippert Soil Fertility Specialist Clemson University Soils 101 Dr. Bob Lippert Soil Fertility Specialist Clemson University

Soil Components AIR Mineral WATER Organic Matter

Soil Components Sand = 2.0 to 0.05mm Silt = 0.05 to 0.002mm Mineral Clay = less than 0.002mm Mineral

1 Millimeter between these lines Six Inch Ruler

50% silt 15% sand 35% clay

Scanning Electron Microscope

Single Cell Animal with “Tail”

Stink Bug Hatching ???

Kaolinite European Union Geochemical facility at Bristol University

Kaolinite

Negative Charge Due To: Isomorphic substitution Edge-of-clay oxygen ions Ionized hydrogen from clay hydroxyl ions Ionized hydrogen from organic materials

Isomorphic Substitution Mg+2 Al+3

Plant Nutrients C HOPKN’S CaFe Mg B Mn Cu Zn Mo Cl See Hopkin’s Cafe Managed By My Cousin Mo Clay

Major Plant Nutrients Hydrogen Carbon Oxygen Nitrogen* Phosphorus* Potassium* * = mobile in the plant

Secondary Plant Nutrients Calcium Magnesium* Sulfur * = mobile in the plant

Micronutrients Boron Copper Manganese Zinc Iron Molybdenum Chloride

The terms Major, Secondary and Micronutrients does not imply that some nutrients are more important than others. The term refers to the relative quantity required by the plants.

Sample Corn Crop Nutrient Requirements 120 pounds/acre nitrogen (major nutrient) 15 pounds/acre magnesium (secondary nutrient) 0.5 pounds/acre boron (micronutrient) The corn yield will be decreased if all of these nutrients are not at optimum soil levels!

Principle of Limiting Factors

Helminthosporium blight Potassium deficiency Nitrogen deficiency

Magnesium deficiency Phosphorus deficiency

Nitrogen Deficiency

Potassium Deficiency

Phosphorus Deficiency

Magnesium Deficiency

Adding fertilizer to the soil without testing is like baking a cake without: 1. Reading the recipe 2. Measuring the ingredients

100 pound bag of 5-10-15 = 5 pounds of nitrogen = 10 pounds of phosphorus = 15 pounds of potassium

Fertilizer Bags

Chemical Forms and Charges of Plant Nutrients Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur Zinc Manganese NH4+, NO3- H2PO4-, HPO4-2 K+ Ca+2 Mg+2 SO4-2 Zn+2 Mn+2

Clay Minerals & Plant Nutrients NH4+ - - Mg+2 - - - - Ca+2 - - - - - - K+ P NO3- SO4-2

Cation Exchange Capacity (CEC) One source of the

How Soils Become Acid Nitrogen fertilizers Carbonic acid & Pollutants Aluminum Iron Organic Matter Calcium Magnesium Potassium

pH A measure of the concentration of acidic hydrogen ions (H+) in the soil solution

The Buffer pH Measures the Exchangeable and Active Acidity

Determining Lime Requirement Norfolk Cecil pH = 5.2 pH = 5.2 Buff. pH = 7.6 Buff. pH = 7.4 Lime = 2 t/ac Lime = 3 t/ac

Ideal

Lime recommendations are based on the type of plant Blueberries = no lime Azaleas & Centipede = pH 5.5 to 6.0 Vegetable Garden = pH 6.0 to 6.5

Liming Materials Calcitic Lime Dolomitic Lime Hydrated Lime Wood Ashes (Use 75% of the above recommended amount) Wood Ashes (Use with caution!)

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