Soil Test

A random sampling of a specific area of soil

Why Test Soils? To determine the amount of a nutrient to be added Determine pH Primary nutrients are the main nutrients tested

Micronutrients? Tissue tests micronutrient deficiencies Results vary within the growing season

Soil Test Results Farmers, greenhouses, and homeowners evaluate the test results and decide whether or not fertilizer should be applied.

Soil pH Measure of the acidity or the alkalinity of a soil

What makes a soil acidic? High concentrations of cations in the soil Cation - positive ion such as H+

What makes a soil basic? High concentration of anions in the soil Anion - negative ions such as OH-

Causes for Acidity in Soil Acid rainfall Harvested crops Most fertilizers Erosion removes Ca and Mg Nitrification

Why do we care? Soil pH determines the availability of certain essential elements Different plants have different pH requirements

Acidic soils Plant signals that a soil is too acidic: –Firing –Stunted growth –Slow germination

Basic Soils Plant signals that a soil is too basic –Stunted growth –Slow germination (Your soil will tell you when something is wrong but you need to get it tested to be sure exactly what)

Relates to soil nutrition pH below 5.8, P will react with Fe to form insoluble iron compound At a high pH, P reacts with Ca and is unavailable The amount of N, P, K available to plants depends on soil pH

The pH Scale Runs from is extremely acidic 7 is neutral 14 extremely basic

Requirements for plants Alfalfa Corn Potato Soybeans Azaleas Generally, plants grow best between

How can we change pH? Adding sulfur or gypsum to lower pH Adding limestone to increase pH