with Tissue Sampling
James Schoff, a farmer from Walnut, Illinois, uses tissue sampling each year. While the number of tissue samples taken may vary from year to year, he realizes the benefits of obtaining this type of data.
"It’s still a learning process for us," explains Schoff. "But tissue samples help us see what we’ve done with our fertility program. Are the plants responding well? Do they have the nutrients they need? As with a lot of new technologies, sometimes we end up with more questions than answers, but over time, the more information we have, the better we can pinpoint fertility issues in our fields."
Schoff is quick to point out that tissue sampling alone does not give a clear analysis of what is happening in the soil. It's important to collect a soil sample at the same location where the tissue sample was taken. This gives a clearer picture of what is happening in that part of the field. For instance, a tissue sample may show a deficiency of one nutrient, but that doesn’t mean it is necessarily deficient in the soil. It may just not be available for the plant to take up, and that changes how to address the nutrient application moving forward.
"Our tissue sampling has helped us identify a trend in potassium deficiency in the late vegetative state of our crop," continues Schoff. “Our soils, though, have adequate potassium. So we are looking at how to supply the plant with additional potassium during those later-season weeks. Without the combination of tissue sampling and soil testing, we wouldn’t know this trend exists, or be able to correct it for future years."
Tissue sampling is a common tool that can provide meaningful data, but it’s only one piece of the puzzle to consider. Complementing tissue sampling with soil test results provides a comprehensive look at how nutrients are both available to and being used by the plant.
On its own, tissue sampling merely provides a snapshot of a moment in time — how nutrients are concentrated in one plant in one part of the field at a particular time. Early growth tissue samples can provide a clear understanding of what nutrient deficiencies exist, and those deficiencies can often be partially corrected with a foliar application. As a crop matures, the nutrient analysis changes, as does the plant’s ability to recover from any nutrient deficiency. Tissue samples taken later in the growing season can be combined with soil-testing data and historical cropping information to determine the best steps forward for the next year’s fields.
The data obtained from tissue sampling can be invaluable; however, with the high risk for errors in collecting tissue, it’s important to remember a few key points:
- Every lab has a set of sampling guidelines for every crop, and they are fairly standardized. Be sure you clearly know which part of the plant should be used for tissue sampling.
- Be sure several samples are taken randomly around the area of the field in question. One or two samples are not enough.
- Do not store plant material in a zip-top plastic bag. Use a perforated plastic bag or a bag supplied by the lab.
- Expedite shipping of the samples to the lab. The less time between when a tissue sample is taken to when it arrives at a lab, the more accurate and usable the results will be.
- Choose one reputable lab to be your partner in data analysis. Choosing a different lab each year can skew results. Using one lab’s results over time will allow trend lines to emerge, and proactive steps can be taken to adjust nutrient levels in the soil before the growing season begins.
- If there is any uncertainty about taking tissue samples, a retailer or crop advisor will use good sampling methodologies to obtain samples.
Tissue sampling is one tool to ensure plants are receiving the proper nutrition each year. With up to 60 percent of yield dependent on soil fertility, every tool to learn more about nutrient levels in the field is needed.