I recently had a discussion with a county agent about using a tissue sample to correct nutrient deficiencies (or the perception that a difference in a tissue concentration of nutrients would translate into a measurable increase in peanut yield If fertilizer was applied. The context was associated with rapid peanut growth after recent rains. Sulfur and nitrogen in tissue were below optimum levels. (I have not seen the tissue analysis report)

Tissue analysis is a reflection of a single point in time. Seldom would I rely on a single tissue analysis to make a management decision. We recommend a soil sample and a tissue sample to help with a recommendation.

In this case, my impression is that rapid growth is leading to some tissue showing a deficiency. However, gypsum contains a significant amount of sulfur, so there should be an adequate amount in soil. Nodules on the root system were adequate for nitrogen fixation. My impression is that the rapid growth caused a transient deficiency. Overtime, my thought is the nodules will provide adequate nitrogen for the plant and the roots will ensure adequate sulfur.

Some farmers are applying granular ammonium sulfate at about 100 pounds even when a nitrogen deficiency is not present (based on canopy color and nodulation.) Sometimes we see a modest yield increase but certainly not every time. The cost of product and application does not result in a financial improvement in many cases, especially this late in the year.