Should You Improve Your Soil ?
The short answer is probably yes. Unless you are incredibly lucky you probably don’t have perfect garden soil, but you do have something to work with to make a much better soil. Let’s start by discussing the factors that make a soil healthy and ready to help you grow better plants.
Healthy growing conditions can be measured in part by the ratio of positive and negative ions in the soil. This ratio is expressed as pH , ranging from extreme acid (positive ions) with a number of 1 to extreme alkali or base (negative ions) with a number of 10. Most commonly grown vegetables grow well at a pH of 6 to 8, with the ideal range around 6.4. This slightly acidic condition makes the necessary elements of plant growth and development more soluble in the water held in the soil and therefore more available to the hair roots of the plants. Plants from more extreme environments may function better at different pH levels, so be sure to research the requirements of your desired plants before making changes to your soil pH. You can adjust your soil pH by adding appropriate materials such as lime, sulfur, peat moss, as well as common kitchen by products such as vinegar and coffee grounds, but is necessary to retest pH every few years to maintain the level desired.
Soil Texture and Pore Space
Soil quality is defined as much by the open spaces it contains as it is by the solids that are the material basis of the soil. Some soils are made up of extremely small particles of near-uniform size and shape, such as colloidal clay. On the other extreme are soils made up of very large and varied particles, sometimes called screes. Neither of these extremes have desirable properties for the typical gardener. Clay offers very poor drainage, waterlogs easily, and allows for very little exchange of gasses with the air above them. The screes have very little ability to retain moisture and allow so much air exchange that many soil organisms dehydrate and die, and have very little ability to retain nutrients for any length of time.
Much has been learned about the major mineral nutrients needed by plants. The fertilizers you purchase are required to state the levels of the major plant nutrients; nitrogen (N), phosphorus (P), and potash (K). The label may also state the levels of other so-called micronutrients such as iron (Fe), Copper (Cu), manganese (Mn), magnesium (Mg), calcium (Ca), just to name some of the more common elements. Many of these elements are already present in your existing soil, but not always in sufficient quantities, or in a form that is available to your plants.
Before making changes in your soil it is necessary to evaluate its present condition. The addition of the wrong amendments or the wrong quantity of the right materials can change the quality of your soil too much in a direction that will not improve growing conditions. We suggest having an initial soil test performed by a professional testing service such as your local agricultural extension agency. More extensive tests can be performed by commercial testing laboratories if your situation requires.