Soil pH vs. Nutrients By: Becky McGuire
What is soil pH? a. soils contain acids and bases b. pH scale indicates acid and base c. pH scale ranges from 0 - 14 d. below 7 = acid/sour e. above 7 = basic/alkaline f. equals 7 = neutral
Optimum soil level a. most plants like soils in the range of 5.5 - 6.5 b. lime (limestone) raises pH (reduces acidity) plants that like acid soils = blueberries, azaleas, rhododendrens
Causes of acid soils a. as nutrients are removed from soil (erosion, leaching, crop removal), they are replaced by soil acids b. acid forming fertilizers (salts) c. nitrification
Adjusting soil pH a. make adjustments on soil tests b. lime raises pH, neutralizes soil acids c. pH lowered by applying sulfur, iron, aluminum sulfate
Desired pH ranges for selected plants a. alfalfa 6.6 - 7 b. corn 6.1 - 6.5 c. grasses 6.1 - 6.5 d. peppers 5.6 - 6.0
Lime sources a. crushed limestone is most common and economical b. contains Ca and Mg
Functions of lime 1. raises pH 2. improves availability of nutrients 3. increases effectiveness of applied N, P, K 4. increases activity of microorganisms improves plant growth and crop yields