Please contact uswith additions or corrections to this listing. Several probes listed here are NOT highly recommended, since they have features which may tend to mis-represent samples. Important: This list is not intended to be exhaustive, and is not an endorsement of these probes or a disparagement of other probes by omission. The purpose of good technique is to develop a sample of about 1/2 lb with at least 20 probed cores. Long probes (greater than 24") or wide diameter probes have the disadvantage that very large samples are generated, which in itself is not a problem, but many labs as a result will not grind the entire sample, which defeats the purpose of careful sampling. On large bales, some studies has shown that it is not necessary to sample to a greater depth, though further studies are being conducted. Length should probe to 14-24" in the butt-ends of the bale.
An extremely small diameter coring device may not cut or represent the leaf-stem ratio properly, and a very large diameter probe may obtain a too-large sample which is difficult for labs to grind properly. Diameter should be between 3/8" and 5/8". No part of the sample (eg leaves or stems) should be lost when the probe is withdrawn from the bale (as it is with open augers). Probes should satisfy a number of criteria: they must fairly represent the leaf/stem ratio of the bales, they should sample deeply enough to represent the variation within bales, the tips should be kept sharp, and tips are recommended to be at 90° to the shaft (not cut at an angle). There are a wide range of acceptable coring devises, each with advantages and disadvantages. The choice of either power-driven or hand-powered probes can be used in an integrated sampling program which includes taking at least 20 cores, sampling at 90 to the but ends of bales, sampling about 18 inches into the bale, and proper sample handling.
of Agronomy & Range Science, University of California, Davis, CA 95616 IntroductionĬhoosing a proper hay probe is an important component of proper forage testing technique. Vance Owens, Ag Hall Box 2207A, South Dakota State University, Brookings, SD 57007-1096 of Agronomy & Range Science, University of California, Davis, CA 95616
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