Organic soil testing provides a way to measure the health of your soil and reduce pest problems.
Do It Yourself Organic Soil Testing
Successful organic gardening depends on healthy, organic soil. One of the easiest ways to test your soil is to buy an organic soil test kit. These kits gauge the health of your soil by utilizing a gel. This specialized product changes color when exposed to differing amounts of carbon dioxide. The kit provides gardeners with explicit directions on how to fertilize plants based on individual test results.
For more information you can you can contact the Natural Resources Conservation Service to download a free a copy of the Soil Quality Test Kit Guide which offers step-by-step guidance when testing your soil.
Where to Get Your Soil Tested
If you don't want to test soil yourself, most land-grant universities offer free or low-cost soil testing services. It is better to use a local analysis provider. Their fertilizer recommendations usually prove to be more beneficial because tests are calibrated to soils for the region where you live. However, before sending your soil sample, make it clear that you are requesting organic soil testing because some university soil testing labs don't offer fertilizer advice suited for organic gardening.
What Soil Testing Provides
Soil testing takes the guess work out of creating a healthy, organic soil that breathes. Results give you the specifics as to what organic additives your plants will require. Tests provide specific nutrient levels and chemical characteristics including:
- Nitrogen (N): Nitrogen promotes plant development and is necessary for encouraging green leaf growth. If you garden lacks proper levels of nitrogen, your plants will exhibit stunted growth or pale green and yellow leaves, retard root growth and makes your plants more susceptible to disease.
- Phosphorus (P): This nutrient is necessary for the development of healthy cells and encourages root growth, especially in fibrous roots. If your organic soil lacks proper levels of Phosphorus growth can be stunted because of poor root development. Another symptom indicating Phosphorus deficiencies are leaves that turn a purplish color.
- Potassium (K): Potassium is needed for chlorophyll formation and is necessary for strong cells that promote the formation of flower and fruit. Strong cells are also necessary to resist diseases, pests and the cold. Without adequate Potassium, your plants will suffer from weak stems and as your plants mature they'll have unhealthy older leaves with yellow tips and brown edges. Soil testing is important, because too much Potassium can lead to delayed maturity.
- Calcium (Ca): Calcium is needed to build cell walls and encourage tissue growth. Since Calcium occurs naturally in organic soil, in most cases supplements are not required. However, if your soil is extremely acid, you may need to amend the ph level. High amounts of acid deplete the calcium in soil.
- Magnesium (Mg): This is another naturally occurring nutrient found in organic soil so chances are Magnesium levels will not need to be amended. However, symptoms of Magnesium deficiency include yellowing mature leaves.
- Sulfur (S): Although Sulfur is naturally found in organic soil, most organic fertilizers do contain Sulfur. While this deficiency does not occur often, soil testing will let you know for sure if you need to add it to your soil. If your soil lacks adequate Sulfur, you plants can experience stunted growth and yellow foliage.
Resources to Help Understand Soil Testing
The following list of resources will help you better understand the biological health of your organic soil and how to test and understand results:
- Defining Soil Quality for a Sustainable Environment
- Methods for Assessing Soil Quality
- Soil and Plant Analysis Laboratory Registry for the United States and Canada
- Microbiological Methods for Assessing Soil Quality
- Manual of Soil Analysis : Monitoring and Assessing Soil Bioremediation
Testing your soil takes the guesswork out of feeding your plants the nutrition they need to grow healthy and strong. Healthy plants also provide the minerals and vitamins needed for a nutritious diet. Organic soil testing leads to a healthier diet filled with essential vitamins and minerals.