Organic Gardener's Composting by Steve Solomon

Evaluating Nitrogen Content

A one-cubic foot bag of dried steer manure weighs 25 pounds and is labeled 1 percent nitrogen. That means four sacks weighs 100 pounds and contains 1 pound of actual nitrogen.

A fifty pound bag of cottonseed meal contains six percent nitrogen. Two sacks weighs 100 pounds and contains 6 pounds of actual nitrogen.

Therefore it takes 24 sacks of steer manure to equal the nitrogen contained in two sacks of cottonseed meal.

If steer manure costs $1.50 per sack, six pound of actual nitrogen from steer manure costs 24 x $1.50 = $36.00

If fifty pounds of cottonseed meal costs $7.50, then six pounds of actual nitrogen from cottonseed meal costs 2 x $7.50 = $15.00.

Now, lets take a brief moment to see why industrial farmers thinking only of immediate financial profit, use chemical fertilizers. Urea, a synthetic form of urine used as nitrogen fertilizer contains 48 percent nitrogen. So 100 pounds of urea contains 48 pounds of nitrogen. That quantity of urea also costs about $15.00!

Without taking into account its value in terms of phosphorus, potassium and other mineral contents, nitrogen from seed meal costs at least eight times as much per pound as nitrogen from urea.