Extension office can test soil to help yield best plants

As many people are planning and planting their gardens in the warm days of early spring, they should be thinking about soil. The overall quality of the soil in gardens and yards determines the potential for growing high-quality plants.

A soil test from the University of Georgia is the most accurate and effective way to assess the nutrient status and relative acidity, or pH, of your soil. Apply fertilizer without a test, and you could apply too much or too little of the lime and fertilizer you need for optimum plant growth.

To collect the soil, take a minimum of 10 random samples in the area that requires testing, and mix the soil thoroughly in a container. Bring two cups of the soil to the extension office for testing. For a small fee, the extension office will mail it to the University of Georgia Soil Testing Laboratory and results will be sent back in seven to 10 days.

Soil tests measure the level of several nutrients of importance to plants, include phosphorous, potassium and calcium. The information is used to determine the necessary nutrient requirements. Nitrogen is not routinely a part of the normal soil-testing regimen, because the test has limited predictive value.

The measurement of the acidity of soil, or the pH, is one of the most important factors in determining a soil's relative fertility. The pH scale ranges from 1 to 14, with 1 being the most acidic, 14 being the most alkaline, and 7 being neutral.

The preferred is pH for our soils in Georgia is between 6 and 6.5, but the average pH is an acidic 4.8.

Since changes in the pH take time, applications of lime are best done months ahead of planting.

The soil-test report shows available soil nutrients and pH, and offers recommendations for improving nutrient levels. Lime recommendations and nutrient recommendations are given in pounds per square feet and are self-explanatory.

Soil test results and fertilizer recommendations can make sense if you take the time to analyze them. Sometimes, however, a homeowner or a business will have peculiar situation or set of circumstances and will need help wading through the numbers. This is where county extension agents and personnel can come into the picture and provide help. Feel free to call your local office anytime.

Timothy Daly is an agricultural and natural resource agent with the Gwinnett County Extension Service. He can be reached at 678-377-4010 or timothy.daly@gwinnettcounty.com.