Did You Test Your Soil?

Edward B. Smolder
WVU Extension Service
Jackson County Extension Agent

If you didn't get a soil test, your garden plan has omitted a vital step. It is best to test soils in the fall, but it is never too late. Your vegetable garden might produce higher yields if it were limed and fertilized properly. The only accurate way to determine how much lime and/or fertilizer to apply is to have your soil tested.

Vegetable plants require certain amounts of nitrogen, phosphorous, and potassium to produce high yields. Some of these nutrients occur naturally in the soil. But most gardens require organic matter and fertilizer to build soil fertility.

Acid soils may prevent vegetable plants from using soil nutrients, even when adequate nutrients are present. If so, you need to correct the problem by applying lime. Too much lime, however, often creates problems similar to having too little lime. Lime doesn't become fully effective until several weeks or even months after application.

Getting soil for the sample is not complicated. You collect a thin slice of soil from the top 4 inches of several well-spaced, representative spots in the garden and mix them together in a plastic pail. Never dry the soil in an oven or microwave oven. Fill the test bag with soil from the pail and mail it.

Be sure to indicate on the information sheet that the crop is a vegetable garden. You will receive a recommendation sheet suggesting how much, if any, lime and/or fertilizer to apply, and other pertinent information about vegetable gardening. Spread the lime well ahead of planting time (preferably in the fall), and broadcast the fertilizer just before plowing the garden. The
garden probably will not require lime again for three or four years. However, the soil should be tested annually to assume optimum soil fertility.

Many garden soil test analyses show a high pH (no lime needed) level and several nutrient salts in the "very high" category. These high levels are caused by the use of excessive lime, fertilizer, manure, or fireplace ashes. Many garden plants perform poorly under these conditions, especially peppers and the root and tuber crops.

If you have any problems understanding the soil test results, contact your WVU County Extension Office.