EDITOR’S NOTE: Today continues a summer series by Daily Journal reporters called “Teach Me Something” where we show how to do a variety of things and how things work.
By Ginna Parsons
TUPELO – You hear it all the time: Before you get ready to plant a vegetable garden or put in landscaping or lay sod, get a soil test.
But what exactly is a soil test, and why do you need one?
A soil test is a process where elements (phosphorus, potassium, calcium, magnesium, sodium, sulfur, manganese, copper and zinc) are chemically removed from the soil and measured for their “plant available” content within the sample.
The quantity of available nutrients in the sample determines the amount of fertilizer that is recommended. A soil test also measures soil pH, humic matter and acidity. These analyses indicate whether lime is needed and, if so, how much to apply.
A soil test encourages plant growth by providing the best lime and fertilizer recommendations; it diagnoses whether there is too little or too much of a nutrient; it promotes environmental quality; and it saves money that might otherwise be spent on unneeded lime and fertilizer.
So let’s begin.
The perfect time to take a soil test
“September through November is the ideal time to take samples of your soil to get your garden ready for spring,” said Susan McGukin, program associate for volunteer management at Mississippi State University’s Extension Service for Lee County. “You have to have time to amend the soil and get it right before you plant.”
Let’s take the samples
Soil tests are done on a sample that is only a tiny fraction of a field, lawn, bed or garden plot. The randomness factor is extremely important for quality. Pull several samples (five to 15, depending on the size of the area) from the distinct area of soil you want tested (lawn, garden, flowerbed, etc.).
To take a sample, using a trowel, take a small amount of soil from the top 4 to 6 inches of the area you want sampled. Walk through the area in a zigzag pattern, taking random samples, and place the samples in a plastic bucket.
Crumble each subsample and mix them all together in the bucket.
Pour the mixed soil out onto newspaper and let it dry; you don’t want your sample to be wet.
Put about 2 cups of the dry mixed soil into a ziptop bag and label it. For example, you might say “front yard” or “west flower bed” or “vegetable garden.”
You’ll want to repeat this process for each area you want tested. If you have a trouble spot in your lawn or garden, a separate sample taken from this area only may be necessary.
Where to go
Now that you’ve got your samples, take them to your local Extension Office. In Lee County, that would be the office on Cliff Gookin Boulevard. There, staffers will transfer your samples from ziptop bags to white cardboard cartons and label each one accordingly.
“Don’t drive all the way to the Extension Office in Tupelo to get the boxes on the front-end,” McGukin said. “All you need is a pint of soil, which you can put in a ziptop bag or in a bucket. When you get out here, we’ll put the sample in the box, help you fill out the form and mail it.”
The cost is $6 for each sample you submit. Make checks payable to Mississippi State University Extension Service (no cash or credit cards are accepted).
A copy of the lab results will be sent to you and to Extension in 10 to 14 business days. There will be a report generated for each sample submitted.
The first line will tell you the overall pH level of your soil. Then it will list elements, such as phosphorus, potassium, magnesium, zinc and calcium, and tell you whether the level of each is low or high.
Then it will give you recommendations, such as “No lime is recommended for this crop” or “Apply lime, if recommended, in the fall or winter.”
“We can talk you through the results when you get them if you don’t understand them,” McGukin said. “We can help you determine what to do from the recommendations on the report.”
So, now that you know what to do, what are you waiting for?