In the Furrow
Peanuts & Pegging Zone Samples
By Will Duffie County Extension Coordinator

Calcium is an essential nutrient for producing quality peanuts. Peanuts produce their own nitrogen and are great scavengers of phosphorus and potassium. But peanuts do have a high requirement for calcium. Calcium is often the essential element most commonly deficient when growing peanuts as seen in some fields in 2006.

A peanut plant that lacks calcium will have a reduced yield and quality. The peanut will often be a 'pop' or have empty hulls and blackheart increases. The lack of calcium will also increase diseases of the developing pods.

Peanuts absorb calcium through the peg into the developing pod. The peanut plant must absorb calcium directly from the soil into the pegs and pods. Therefore adequate levels of calcium must be in the top 3 inches or "pegging zone". As in 2006, if soils are extremely dry, fields with adequate levels can experience problems due to calcium not being in solution.

Soil samples are good indicators of calcium levels, but should not stand alone. Calcium can leach so calcium levels from winter liming may be low. For this reason a pegging zone sample may be beneficial.

Which peanut fields need a pegging zone test? Peanuts grown for seed and large seeded runner varieties such as C-99R and GA 01-R do not need to be tested because these fields should automatically receive a calcium application. Fields that received a lime application up to three months prior to planting do not need to be sampled. Fields not in the above situations should be sampled. Take samples no deeper than three inches. Go to several random areas of the field to take the samples. Avoid noticeable areas, such as low, wet bottoms, that may skew the sample. Mix the soil from the several sample locations to get a uniform, random sample of soil. Mark the bag for "pegging zone" sample. Results will provide the producer with the calcium level and the calcium to potassium ratio. These values will determine if additional calcium is needed in the form of gypsum.

The critical values are that there needs to be a minimum of 500 lbs/acre of calcium and a 3:1 ratio of calcium to potassium for GA Green, GA 02-C, AT 3081 and AT 3085. The level for AP- 3, GA 03-L, and FL07 should be at a minimum of 700 lbs/acre. A pegging zone sample cost $3 each and bags are available at the Extension Office. For more information contact us at 706-554- 2119.