Given the retail prices of N, P, and K – (Nitrogen, Phosphorus, and Potassium) from Butterfield Grain Associates in Meadville, MO.
Nitrogen – 3.71 lbs times .42/lb = $1.56
Phosphorus – 1.63 lbs times .35/lb = $0.57
Potassium – 8.875 lbs times .29/lb = $2.57
Total NPK value = $4.70 per 1250 lb hay bale or $12.17 per ton.
This value doesn’t include micronutrients and the organic matter in manure and wasted hay, including calcium, magnesium, etc.
Purchased bales of mature warm season grasses weigh about 1250 lbs each. I sent core samples to Ward Laboratories to have analysed for feed value as well as fertilizer value. Here are the results: