Soil Testing



Soil testing is a valuable tool of the home gardener. Samples are collected and can be tested by either delivering the samples to your local county Department of Agriculture Extension Office or by using your own soil testing kit. Soil testing by the agriculture laboratory is inexpensive, and you will receive a report indicating the deficiencies of the major nutrients which are essential for plant growth. These nutrients include nitrogen (N), phosphorus (P), and potassium (K). The soil testing report will also indicate the pH, which is a measure of the acidity or alkalinity. The pH directly affects the availability of the nutrients to the plants. The downside of using the Extension Office is that it will require some waiting for results. We have used inexpensive soil testing kits during our farming experience and have found them to be easy to use and the results quite satisfactory, provided that the instructions are closely followed.

AccugrowT Soil Test Kit

AccugrowT Soil Test Kit

You can easily perform a soil test whenever the need arises.


Sampling

Sampling for soil testing is a relatively simple procedure. The main rule to follow is to always wash or hose clean the sampling equipment prior to each sample collection. Take samples from at least three locations in each area of the garden where major crops will be grown, since different crops remove and require nutrients from the soil in varying amounts. For example, corn is a heavy nitrogen user whereas beans actually fix nitrogen into the soil. Take each sample from the surface to a six inch depth with a clean trowel. The soil should be dry to slightly moist. Mix the samples together thoroughly in a clean container. A minimum of two cups of each combined sample is required by the county Extension Office for soil testing. It is recommended that soil testing and fertilizing should be performed several months prior to each planting season in order to allow lime to react with the soil.


Using Soil Testing Results

ComposT-Twin with Free Activator The soil testing report from the Extension Office will indicate how much commercial (chemical) fertilizer and lime are required for good growing conditions. These reports, as well as home soil testing kits, focus only on the primary nutrients required by plants. However, there are many micronutrients which plants use which are important for the plant and especially for the human who consumes it. These micronutrients are constantly being depleted on lands which use commercial agricultural methods exclusively. An excellent way to add micronutrients is by spreading several inches of compost over the garden planting area prior to turning it over. Compost can serve double duty by also acting as an amendment in clay-like conditions just by spreading four inches over the planting area the first year.


Deluxe Pyramid Composter

Final Tips

•    It is important to spend time researching each crop’s nutrient and pH requirements when planning your garden.

•    Fertilizer and lime can be added along each row or planting hole to selectively meet nutrient and pH requirements. Mix in thoroughly or the chemical fertilizer and lime will burn the roots.

•    For those interested in using environmentally friendly sustainable growing methods, see our section on Organic Gardening.