How to Test and Improve Soil

Different plants need different degrees of alkalinity and acidity in the soil. This helps plants pick up different kinds of nutrients from the soil, which are essential for proper growth.

A more alkaline soil has a higher concentration of lime than an acidic soil. A soil's pH factor measures its neutrality or the degree to which these two factors balance each other. A pH of "7" is characterized as acidic. Most plants thrive in soil with a pH balance between 5.5 and 7.0.

A professional laboratory can test soil, or you can get a basic indication with a home test kit. However, the most popular and economical method is to take your own samples and send them to a lab for analysis. You can ask your local garden center or county extension agent for a list of laboratories and the kind of tests they do.

The cost is minimal per sample, and takes one to several weeks to analyze. The lab report will give the amount of lime to add to an acidic soil, or the amount of sulfur to balance an alkaline soil. The report will also give the soil's deficiency reading, if any, for the nutrients phosphorous and potassium, as well as other pertinent information.

Nutrients can be added to the soil by adding fertilizer. Lime and sulfur are applied like fertilizer, but are administered in different amounts. Lime is generally applied at the rate of a half-pound per square yard, but this rate is not an absolute. That is why it is best to have the soil lab-tested for precise recommendations. Sulfur is applied at the rate of approximately 20 pounds per 1000 square feet, but a test will be needed to confirm or deny that.

Soil chemistry changes over the years as it is gardened and can become either too alkaline or acidic. It is best to test heavily gardened areas every three to five years. It is also good to test the soil of new properties. Most soil is tested for either vegetable garden or lawn use, however, rose gardens, flower beds and foundation plantings need the same input.

Soil chemistry can vary from location to location within the same property lines. In order to gather an accurate sample for testing, it is best to take five to six sample capfuls from different areas of the yard, let this soil air dry, and then blend together and send one capful to be tested.

Soil can also vary in its texture and structure. Very hard, dense soil generally contains a large amount of clay. Extremely grainy soil contains high amounts of sand. Soil structure can be improved in either type by adding organic matter such as composted materials from chopped leaves, grass clippings and appropriate table scraps.

Soil chemistry is important for a plant's health. Testing is very simple and worth your time and effort.