Testing garden soil can improve your chances for success

By Rennie Phillips

Probably six or seven years ago, I contacted Kelso Milling here in Scott City about getting fertilizer for our place. So I kind of figured how many acres were in each of the pieces of ground we had fenced off. Kelso Milling recommended how much of a general-purpose fertilizer to put on per acre, and I used our pickup to pull the buggy home, which was a breeze.

It took a little bit of work getting the buggy hooked up to our Massey 135, but it wasn't difficult. I hooked the power take off and then figured out how to set the controls for the fertilizer application.

All that was left was to get with it. Not sure we did it right, but we did it. Adding the fertilizer really seemed to help; it seemed like the grass was thicker and greener.

One of the areas that we fertilized is now part of our garden. I have added fertilizer and lime each year, but I really wasn't sure how we were doing in regard to pH and goodies in the soil. So I picked up four test envelopes from the University of Missouri Extension office in Benton, Missouri. I got a sample from each of the high tunnels and two from our big garden. Since the garden is over 100 yards long, I got a sample from each end.

I had the results emailed to me, which I received about a week later. I believe the cost for each of the tests was $9, which I believe is pretty reasonable.

This basic test is for pH, phosphorus, potassium, calcium and magnesium. They also list the amount of organic matter in the soil.

After getting the results, I talked to them in Benton and decided to get a trace-mineral test on the two high tunnel soil samples. The cost is $8 per test.

The outside garden's test results were pretty much how I thought they would look. The pH was 5.1; it should probably be about 6.5.

Since I grow a variety of vegetables in this garden, I need a mid-range pH. The recommendation is to add 120 pounds of lime per 1,000-square feet. The test was decent for phosphorus and potassium, but it was low for calcium and magnesium. So the recommendation is to add 3 pounds of nitrogen, 1 pound of phosphorus, 1 pound of potassium and no magnesium per 1,000 square feet of garden.

It's really not that much fertilizer.

Nitrogen is the one fertilizer that will make the most difference in how the garden goodies grow is nitrogen.

The two tests in the high tunnels covered a bunch of elements. Some of these are phosphorus, potassium, calcium, magnesium, sulfur, boron, copper, iron, manganese, zinc, sodium and organic matter. It also showed the pH as being 5.7 and 6.

The only elements that are needed are lime, nitrogen, phosphorus, calcium and potassium.

The test showed I need 1 pound of potassium, 1 pound of phosphorus, 4.5 pounds of nitrogen and 26 pounds of lime per 1,000-square feet.

Each of our high tunnels is about 1,000 square feet, so my next step is to check with Kelso Milling about fertilizer.

General purpose fertilizer has nitrogen (N), phosphorus (P) and potassium (K) in it.

These are always represented by three numbers in the same order -- 10-10-10.

These numbers mean a bag of fertilizer contains 10 percent nitrogen, 10 percent phosphorus and 10 percent potassium. So in a 50-pound bag of 10-10-10, there is 5 pounds of nitrogen, 5 pounds of phosphorus and 5 pounds of potassium.

Since I mainly need nitrogen, I'll probably treat the tunnels only with nitrogen or Urea, which I also bought. I will be extra careful not to spread more than the recommended amount.

The only other element that I will add is some calcium. When tomatoes lack calcium, they will develop blossom-end rot.

A hard black spot will develop on the bottom of the tomato, which ruins it. Once the disease shows its ugly head, it is hard to treat.

The best thing to do is provide calcium throughout the growing season.

I add a specific tomato fertilizer and nitrate, 4-18-38, to the water.

The best way to test the soil in your garden is to stop at the Missouri Extension office in Benton or Jackson and pick up the sample envelopes.

If you have several areas to test, I'd get an envelope for each area. If you have a small garden, get some dirt from several places, mix the dirt and then fill the envelope up to the designated line.

Take the sample to the office, and in a week or two, you should get the results.

I sure don't understand everything when it comes to fertilizer.

The guys and gals at the extension office know a lot more than I do. Ask them for help.