Soil Tests Help Answer Questions
AVA, MO.
Having soil tested is the first step to having a more productive pasture or garden. Ben Polley, a graduate student working for the University of Missouri Extension in Douglas County, recommends having soils tested prior to fertilizer applications or, for well-managed operation, every two to three years.
“You can’t make good fertility decisions unless you know what’s there” said Polley. “Amending untested soils can waste money, result in disappointing yields, and harm the environment.”
To collect a sample, take 15 to 20 cores from each area tested. Due to soil variability, this area should be no more than 20 acres but can be as small as desired. Samples can be taken by walking in a zig-zag pattern throughout the area and pulling soil cores from a depth of six to seven inches.
Sample probes are available from local county Extension offices.
Break up and mix the cores in a clean bucket. A total sample volume of about two cups is needed for testing. Samples can be taken to a county extension office and tested for a fee.
“Fertilizer prices are down right now,” said Polley. “It’s a good time to invest in fertility but you can over or under apply if you don’t test your soil.
In addition to showing the amount of nutrients in your soil and providing recommendations, a soil test determines the pH of your pastures or plot.
“Soils in the region tend to be acidic and that limits the amount of nutrients that available to be taken up by the plants,” said Polley.
A pH of 6.0 to 6.5 is optimal for most crops grown in the area. There are, however, a few exceptions. Alfalfa needs a pH of at least 6.5 whereas blueberries need a pH of 4.5-5.0.
“Ensuring the pH is correct for what you’re trying to grow is paramount,” said Polley. “If it isn’t, the nutrients your plants need won’t be as available. The pH reading is one of the first things I look at on a soil sample report.” ∆