Whether you’re a rancher growing hay, a farmer growing cotton, or just a homeowner wanting to have a pretty yard, the place you should start is with a soil sample.
You’ll want to take ten to fifteen sub samples of the proposed growing area and submit it to a lab for analysis.
Tony Provin is a Texas A&M Agrilife Extension professor and soil chemist, and described how to take a soil sample.
“The sampling protocol, traditionally for a routine soil sample, whether it’s an urban or an ag side is going to be zero to six inches deep. Our key aspect though is, when you’re collecting that soil sample, you’re not submitting plant tissue. If it’s a root, we’d like to remove that. If it looks like it was a plant, and you can still identify it was a plant, we remove that material. Often it’s easiest to do that by just kicking the very surface off.”
Provin emphasized anything that has been broken down into soil should be included in the sample.
“However, if you can’t tell it used to be a plant, it’s just some round black material, that is now soil, and that would go to the laboratory. So we would collect the soil sample, in this case with a push probe, and this heavy residue, we try to kick the tissue off to the side so we don’t have a lot of small material that’s going to get in the way of taking the sample and having to pick all those tiny pieces out later on, and we would push down at least to a depth of six or seven inches, we’re going to take a zero to six inch sample so we want to go a little bit deeper, and then we can either use a tape measure or a marking and we would collect everything on the top side of that, and then we would take this individual core, and place in our clean plastic bucket.”
Any material deeper in the probe would just be discarded back into the field. The research that supports the fertility and nutrient recommendations is based on sampling depths of zero to six inches.