It’s November, time to take soil samples.

To make the process easier, this month Texas AgriLife Extension will provide soil sampling kits, including sampling bags and instructions, found online and at most county extension offices. Once samples are collected, producers can mail them directly to the Texas A&M Soil, Water and Forage Testing Laboratory in College Station.

Soil testing information from Texas A&M can be found online.  Included are instructions on how to sample, what types of tests you can choose to meet specific needs — basic nutrient test or a complete analysis of nutrients, organic matter, salts — and additional nutrient information.

Discounts are available for a variety of tests when groups of eight or more samples are submitted at the same time for the same test. But check with your local AgriLife Extension office for special pricing in November in most counties.

“Composite samples are recommended for each test to represent the entire area to be fertilized or treated. Soil types can change within a field, so multiple samples to represent all soil types are critical,” says Laramie Naumann, Colorado County Extension agent for Ag and Natural Resources.

Texas AgriLife Extension guidelines recommend 10 to 15 cores of soil from the sampling area (up to 40 acres) is adequate.

In an online article Calvin Trostle, Extension agronomist at Texas A&M University Soil & Crop Sciences in Lubbock, offers additional considerations to help capture more value from soil test results.

For larger farm or ranch operations, he suggests landowners may wish to rely on a crop consultant or a commercial testing company to conduct soil sampling because of the time, labor and special equipment that can be needed to gather core samples. He says it is important to know which lab contractors plan to use and be prepared to recommend which one they select.

Sampling depth is also important. Some states recommend deeper soil samples to gauge deep nitrogen levels, Texas A&M recommends sampling at 6 inches. They suggest that depth is generally sufficient. They may want to take additional core samples at 18 to 24 inches and test only for nitrogen if desired. This method of testing could save farmers from expensive testing of all samples at the greater depth.

“We do recommend greater attention to soil nitrate-nitrogen below 6 inches. The Texas A&M Soil Test Lab now provides a “Profile N” soil test form,” Trostle says.

In addition, he recommends using an in-state testing laboratory and avoiding test laboratories located out-of-state as their fertility recommendations may vary greatly.

He also said an additional benefit of annual soil testing includes the ability to demonstrate soil fertility to any potential buyer or lease operator of all or some of a landowner’s property. Trostle believes soil testing could mean higher value of your land by proving the field or farm supports healthy crop and pasture production.

Self-testing soils

Naumann says testing with the Texas A&M soil test kit should limit all core samples to 6-inch depths. A trowel, spade, or soil probe can be used to collect samples.

The soil testing form provided by the lab offers a total of 10 different analysis suites or soil tests. The most common tests used are a routine analysis or a routine plus micronutrients test. The routine test will determine the soil pH, salinity, nitrates, phosphorus, potassium, calcium, magnesium, sodium, and sulfur content of the soil. It provides basic N-P-K fertilizer recommendations for the selected crop.

The routine-plus test provides all of the information from the routine test in addition to estimating the levels of zinc, iron, manganese and copper available to plants in the soil. This test is usually chosen for specialty crops, or to help troubleshoot deficiencies.

Many farmers choose not to test soils every year, but soil scientists generally recommend that soil tests should be done at least every other year.