Soil Samples Analyses and Interpretation

PPM parts per million average weight of 6 inch soil =2 million pounds 1 ppm = 2 pounds / acre

pH measure of soil acidity or alkalinity tells if you need lime, not how much active acidity neutral rice < 5 can add lime good above 7 may cause Zn deficiency

Buffer pH measure of total acidity used to determine lime requirements of soil

Effects Salt May Have On pH if high soluble salts are present, pH may appear lower than actual if you suspect a problem, then you should notify lab

CEC Cation Exchange Capacity measure of soils ability to retain and exchange cations determined by the amount of soil colloids that are present

Whats A Cation? positively charged ion common soil cations include: –aluminum (Al), calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) held to colloids in that order –Al tightest –Na weakest

Soil Colloids clay organic matter - humus colloids - not small enough to form true solution, too small to settle out negatively charged

Different Labs/Businesses Different Recommendations? extraction techniques interpretation philosophy replacement maintenance base saturation