Any master gardener will tell you that having the proper pH balance and nutrients in your soil will determine how well your plants grow. Soil that is deficient in one or more nutrients can cause plants to become drought and frost resistant, prevent them from absorbing water and minerals, and hamper seed and root growth. A way to ensure your soil has the correct pH balance and the nutrients needed to produce a healthy garden is to test the soil. This can be done with a soil testing kit or by sending soil samples to a laboratory for testing.
Soil testing kits and laboratory testing both basically measure the pH balance and the amounts of nitrogen, potash (potassium), and phosphorus within the soil. Soil pH is what determines whether or not plants are able to absorb nutrients. Nitrogen is needed for healthy plants stalks, stems, leaves, and grasses. Phosphorus aids in root stimulation, blooming and seed formation, and helps plants get an overall healthy growth started. Potassium stimulates early root and tuber formation for underground vegetables such as carrots, radishes, and turnips, plus tuberous flowers such as begonias, dahlias, and lilies. In addition to purchasing soil testing kits on-line, most nurseries and garden shops carry them.
Whether you decide to use a soil testing kit or have your soil sent to a lab to be tested; you first need to know what you want to test. There are soil testing kits that test for pH balance only and some that test the pH balance plus nutrient level. Labs will also only test what you ask and pay for to be tested.
A soil testing kit is generally easy to use and cheap, providing you use it more than once. Some come with test strips which are chemically coated, while other are more elaborate with bottles of chemicals. Keep in mind that the chemicals used to test the soil will lose their strength after time, rendering the kit useless. Soil testing kits give a very general overview of what your soil is lacking and even a more general overview of how to correct. Some may include instructions and charts on what to do to get your soil to the correct pH and nutrient level. There are more accurate soil testing kits available, but they range in the hundreds of dollars.
If you would like a more in-depth analysis of your soil, then laboratory testing is the way to go. Most state universities have extension offices that provide soil testing for a small fee. You can go on-line to find these or ask at a local nursery or garden shop where you can have your soil tested. Laboratory testing can provide a pH value as accurate to within a tenth of a unit, as well as the nutrient results to be within a few parts per million. Professional technicians are conducting the tests so this leaves little room for error, plus they are available to offer recommendations to the specific plants you grow based on the latest research. It is not as easy for laboratory professionals to give recommendations on results from soil testing kits as kits can use different ratings.
Whether you use a soil testing kit or send your soil to a laboratory, it is important to obtain a good soil sample. Use a clean trowel or hand spade and gather soil samples two to three inches below the surface in areas that may vary, such as a sunny and a shady spot, or perhaps an area where water collects. Try to avoid touching the sample with your hands, as soaps and lotions on hands can prevent accurate test readings. The soil should not be wet when gathering and remove any debris such as stones, weeds, and wood chips.
Once you have your test results and recommendations for soil improvement, all that is left to do is to apply the necessary nutrients and fertilizer to your soil and watch the vegetable and flowers thrive.
Source: Heirloom Seeds, Extremely Green Gardening Co.