Though the weather has been very cold lately, here, in the middle of winter, spring is around the corner, and many of us will be planting our yards with an assortment of plants. One of the most important needs of plants is good soil in which they grow. A soil test from the University of Georgia is the most accurate and effective way to assess the nutrient status and the relative acidity (pH) of your soil. Applying fertilizer without a test can lead to applying too much or too little lime and fertilizer needed for optimum plant growth.
To collect the soil, take a minimum of 10 samples randomly in the area that requires testing and mix the soil thoroughly in a container, such as a bucket. Bring two cups of the soil to the Gwinnett County Extension office, at 750 S. Perry St. Room 440, Lawrenceville, office hours 8 a.m. until 5 p.m. Monday through Friday except holidays. You will then place the soil in a small bag, and fill out some information on the side of it. You should do separate soil tests for lawns, ornamental trees and shrubs, vegetable gardens, and others. For a small fee, the extension office will mail it to the University of Georgia Soil Testing Laboratory, with the results being sent to you in seven to 10 days by mail or e-mail. The cost is $8 per sample.
Soil tests measure the level of several nutrients of importance to plants: phosphorous, potassium, calcium, magnesium, zinc, manganese, and pH. The information on the nutrient levels, the pH, along with the crop to be grown is used to determine the necessary nutrient requirements. Nitrogen is not routinely a part of the normal soil-testing regimen since the test has limited predictive value. Nitrogen is quite mobile in the soil and may be leached out before planting. Recommendations given are based on the amount of nitrogen required for the plant growth in a year.
The soil test report shows available soil nutrients and pH, and recommendations for improving pH and nutrient levels. Lime recommendations are given in pounds per square feet and are self-explanatory. Nutrient recommendations are also given in pounds per square feet.
Soil test results and fertilizer recommendations can make sense if you take the time to analyze them, and the dead of winter is one of the best times of the year to have soil tested. Sometimes, however a homeowner or a business will have peculiar situation or set of circumstances and will need help wading through the numbers. If you are confused with the result, please contact Gwinnett County Extension for assistance.
Timothy Daly is an agricultural and natural resource extension agent with Gwinnett County Extension. He can be contacted at 678-377-4010 or firstname.lastname@example.org.