The Indiana Certified Crop Adviser panel includes Gene Flaningam, Flaningam Ag Consulting, Vincennes; Carl Joern, Pioneer, Lafayette; Greg Kneubuhler, G&K Concepts, Fort Wayne; and Dan Quinn, Purdue University Extension corn specialist, West Lafayette. 

 

My agronomist typically pulls tissue samples at three key times during the season. He claims they are interesting, but he has yet to recommend we do anything different based on them. Is this a cost I could do without this year?

 

Flaningam: Tissue samples can help provide data in fine-tuning your fertility program. In-season corrective action will depend on the crop’s growth stage and availability of post-application equipment. Environmental conditions, such as cool, wet soils, soil compaction and drought, have a significant role in tissue sampling results. Use sound judgement when making corrective actions in-season with plant tissue sampling.  

 

Joern: Historically, growers felt tissue tests didn’t translate into actionable decisions. But newer research is showing that high‑yielding corn and soybeans consistently hit higher nutrient sufficiency levels, and those ranges differ from many of the “old” published benchmarks we’ve all been using for decades. That means the value of tissue sampling is changing. 

 

Pioneer’s multiyear dataset found that nutrient concentrations at key growth stages often correlated strongly with yield, and that the highest‑yielding fields hit clearly defined nutrient ranges that lower‑yield fields didn’t. In other words, tissue sampling can now help you understand whether your crop is truly on track to achieve the yield you’re paying for.

 

If cash is tight and you need to cut somewhere, tissue sampling is a place you can cut, but understand the trade‑off. You’re giving up your best chance to identify a correctable nutrient issue before you see symptoms and before it quietly robs yield.

 

Kneubuhler: Tissue sampling can provide useful insight, but in many cases, it becomes more of a diagnostic exercise than a true decision-making tool. By the time many tissue results are received, especially at midseason or later, the crop has often already lost yield potential or the available corrective actions deliver inconsistent results. For that reason, routine sampling across multiple timings is often a cost that can be reduced without negatively affecting performance.

 

Keeping a single early-season pass around V4 to V6 in corn or early vegetative stages in soybeans can still provide value, as there is time to respond to deficiencies. Beyond that, sampling should be targeted toward specific problem areas or management zones to help diagnose underlying issues and inform future fertility decisions. By scaling back to this focused approach, you can significantly reduce costs while retaining the limited but meaningful benefits of tissue testing.

 

Quinn: Corn tissue testing is most valuable when it helps answer a specific question. Its greatest strength is diagnosing a problem when something in the field looks off, such as uneven growth, striping or discoloration. Comparing samples from good and poor areas can reveal whether a nutrient issue is involved or whether the real cause is something else, such as compaction, restricted roots, disease or water stress. Tissue testing can also uncover “hidden hunger,” where nutrient levels are low but not yet causing visible symptoms. 

 

Where tissue sampling tends to lose value is when it is done routinely but never leads to a deficiency diagnosis or change in management. If multiple years of samples have not resulted in different fertilizer decisions, in-season adjustments or identification of recurring nutrient issues, then it may be reasonable to scale back. Instead of three scheduled sampling times across every acre, consider sampling only high-risk or high-variability fields, or only when visual symptoms or uneven areas appear.