Estimating Nitrogen Sequestered in Northern Red Oak Acorns

Acorn Production in Northern Red Oak Stands in Northwestern Pennsylvania 

Is a paper which documents an research on acorn yields of (primarily) even age forests in 21 different oak stands over a four year time span.

Acorn production ranged from a low of approximately 7000 acorns per acre ( 70 pounds) to 270,000 acorns per acre (approximately 2700 pounds).

 In an attempt to make those numbers easier to visualize, a standard sheet of plywood or OSB is 8 feet long by 4 feet wide, or 32 square feet.  Those yields over the course of the study ranged from 5 acorns per (32 square feet) to 200 acorns per (32 square feet).

Nitrogen

Acorns for oak in the Red Oak family tend to be higher in protein and oil than acorns in the White Oak family.  If White Oaks are the maize of the tree nuts, then Red Oak are the soy beans.

Red Oak acorns have been quoted as up to 35% protein by dry weight (14% by wet weight).  Protein is sixteen percent (16%) nitrogen by weight.  Skipping over a boatload of math (and assuming 100 Northern Red Oak acorns to the pound) one can approximate the pounds nitrogen per acre sequestered by a crop of  Northern Red Oak acorns by counting the number of  acorns in our 32 square foot sample patch and multiplying by 0.3

For the Pennsylvania study, the amount of nitrogen sequestered by the highest crop recorded was approximately 60 pounds per acre.  This may be slightly underestimated because 100 acorns/pound is a little on the small side for Northern Red Oak acorns.

Caveats

These approximations are for acorns in the Red Oak family.

SWAG multipliers for other species are:

Shumard Oak 0.25 X (Number of acorns in 32 square feet)

Scarlet Oak  0.1 X (Number of acorns in 32 square feet)

Most other Red Oaks  0.08 X (Number of acorns in 32 square feet)