The ag industry is beginning to take a closer look at tissue sampling, taking as many as three different samples during the season to find out what's happening in the plant. Several companies are now tissue testing for their customers.
Local agronomists report that it has helped them uncover things like sulfur deficiency that was holding back yield. Sulfur is a nutrient that used to be free from the air. With all the tightening of regulations of sulfur emissions from power plants, particularly coal-burning power plants, there are cases where sulfur could be deficient, depending on the soil. One of those situations can occur on sandy, low cation exchange capacity soils.
Betsy Bower, with Ceres Solutions in Terre Haute, Ind., has helped customers identify a sulfur deficiency with routine tissue sampling. Sulfur is an element that is hard to quantify through soil test because it moves around in the soil, she says. If sulfur is limiting on low CEC soils, a sulfur application at the right time can mean 15 to 20 extra bushels of corn per acre.
On the other hand, some university agronomists are concerned that there are not good recommendations available to take tissue test results and know how much of the micronutrient to apply.
What all sides agree upon is that tissue sampling is useful to help troubleshoot situations where plants are showing obvious symptoms of a deficiency. In those cases most agronomists recommend pulling both tissue samples and soil samples from the affected area. You may also want to pull soil samples and tissue samples from a good area since field which is not showing symptoms. This may help identify a major nutrient problem, such as potassium deficiency, which could severely limit yield. It may need to be corrected first before other steps aimed at adding yield will be effective.