Gardening can be enjoyable and help save money by providing fresh vegetables and herbs. There are a few different options you can do to transform some of your yard into garden space but before you begin planting for the season, it is important to know the state of your soil and what you may need to add to your soil for fertility for optimal growth. You may be tempted to add lime without adding a sample, but the truth is adding lime when it is not needed can be harmful to the soil and plants and actually prevent anything from growing and damage the plant roots.
Testing a soil fertility sample is also important in determining pH values and nutrient levels. The test results then can provide recommendations on planting and adjusting fertility with (N) Nitrogen and (P) Phosphorus.
If there are excessive amounts of N (Nitrogen) it can lead to contamination in wells and water supplies and elevated levels of NO3. Excess amounts of P (Phosphorus) in streams can lead to excess growth in algae and other weeds where decomposition of the growth consumes oxygen otherwise available to fish leading to deaths in fish life.
pH is the measure of acidity or basicity (alkaline) in a soil or solution. Mathematically expressed as pH = log(1/H+) activity in miles H+/liter.
Measuring pH can be done in the lab with a water test using a 1:1 water to soil ratio. Two tests are preformed, one for the pH and a second (buffer test) to determine the acidity if the pH is lower than 7.0.
pH can influence the mineral weathering in soil as well as decomposition of organic matter. pH can also have an effect on the performance of some pesticides. Another relationship is the effect of the cation exchange capacity (CEC), the capacity to hold positively charged cations like K, Mg and Ca.
The pH in soil controls the availability of nutrients by affecting microbial activity. An optimal pH value for the availability of nutrients can be achieved by adjusting the pH value where toxic materials are absent. Increasing a pH value above 5.5 would decrease aluminum activity which can be toxic to plant roots. A value lower than 4.5 can inhibit Rhizobium bacteria.
pH can be increased by adding other materials such as limestone and mixing with a fertilizer.
pH can be reduced with sulfur, Sphagnum moss peat, and Iron sulfate.
There are soil fertility sample test kits available for use in the field and once you have the soil you just simply send it to a lab for analysis. A sample can be collected by digging a small hold about four to six inches deep to sufficiently collect soil. You want to collect about 2 cups worth. Do not use brass, bronze, or galvanized tools because they will contaminate the sample. Let the soil dry in a tray for about three to four days or longer depending on humidity. Then simply send in the sample with a garden vegetable form. Within two weeks you will receive your results with recommendations on fertilizers and how much to apply.
