Gypsum Applied at Planting Peanut Notes No. 48 2021

— Written By

Question:

What should the index be for calcium on soil reports for peanuts? Have a person that will grow peanuts in sand and hasn’t had peanuts in years and wanted to make sure he had ample calcium.

Last year he applied normal landplaster but still had a lot of pops. I was thinking maybe put 800-1000 lbs of plaster out now and then come back later with normal rate of plaster. His index values are 40-65 now.

Jordan:

Has the soil test called for calcium as a recommendation? I don’t think putting any out now will help relative to the need in the pegging zone during fruit set. Excessive rain after gypsum application or dry weather during pegging and fruit set can cause pops even if gypsum is applied. Was either the case in previous years?

Follow up:

We had a couple weeks but worst pops were on somewhat lower and stronger land. Soil test does not recommend any extra calcium.

Jordan:

I also think gypsum is going out earlier than needed and if rainfall occurs after application (excessive) we run out late in the season. Keep in mind if you up the rate and the pH is marginal you can do more harm than good. Not sure this explains the pops in the low areas. I just don’t think gypsum now, at planting, which would likely not be in the pegging zone later, will help.

Noticed that this is a field that has not had peanuts in a while. Getting liquid inoculant in the furrow with seed might be the most important practice he will do.