Tissue sampling is conducted in-season, and its subsequent plant tissue analysis can be used as a diagnostic tool to identify potential issues with a crop. At its core, plant tissue analysis shows the nutrient status of the crop at the time of sampling and can detect unseen deficiencies or confirm visual symptoms of deficiencies.
“We look at tissue sampling as an in-season monitoring of our progress and how nutrients are taken out of the soil,” said Meagan Kaiser of Perry Agricultural Laboratory. “It helps us match up where we’re seeing good tissue results and then overlay that with our yields. It helps us compare our infield observations with an actual data source.”
According to Kaiser, tissue testing can also help rule out whether or not a nutrient deficiency is actually the cause of visual symptoms. “So often, I think farmers can kind of confuse the disease with nutrient deficient or they tried to treat a disease with a nutrient application. If I am seeing some sort of damage on the leaf, tissue sampling is a good way to rule out nutrient depletion versus other pests or disease,” she said.
For sulfur deficiencies specifically, farmers may notice that younger leaves are small and pale green or yellow. The farmers may also notice that stems are thin, hard and elongated. Taking a tissue sample can help determine if a sulfur deficiency exists or if the symptoms are caused by something else. The results of the tissue test can inform in-season decision-making and help farmers determine what to do next.
“It’s a snapshot of that point in the growing season. There are some cases where we can use tissue testing to reiterate when it would be a good time to put on nutrients like nitrogen and sulfur. With soluble nutrients like ammonium sulfate, for example, that’s something we can get on in-season relatively easily once a tissue sample helps us diagnose that,” she said.
If the results indicate a sulfur or nitrogen deficiency, there may still be an opportunity for an application of ammonium sulfate (AMS) to provide readily available sulfate sulfur and ammonium nitrogen to the crop. Sulf-N® AMS can be topdressed between R2 and R4 to help ensure soybeans have the sulfur and nitrogen needed for grain fill later in the season.
Overall, soil and tissue samples provide valuable insights for crop nutrition programs. As an agronomic adviser, the results from these tests can enable you to have better conversations with your farmer customers about the nutritional needs of their crops.
“If you don’t measure it, you can’t manage it,” Kaiser said. “Consistent and timely soil and tissue testing overlayed with yield data help us draw conclusions and make data-driven decisions about what the right fertilizer rates are as well as the right timing for the applications.”