Value of Manure Slurry Nutrients
You can look at liquid manure or industrial sludge in one of two ways: (1) A stinky smelly mess that costs money to dispose of, or (2) A valuable source of organic fertility with the macro-nutrients of N-P-K, as well as the micro-nutrients and humus.
Yes, it costs money to clean out a lagoon either through pumping, dredging or excavation; but the residual value of the manure can partially offset if not total pay for the cleanout costs. The value of the effluent water depends on the nutrient value contained in the product and how much fertility an agriculture field needs in any given year.
The nutrient value of manure is determined by the type of animal producing the waste as well as what type of feed was given to those animals. The Nitrogen value of manure is better preserved in a liquid form. Effluent that is injected directly into the ground prevents Nitrogen loss due to volatization (denitrification and off gassing of ammonium Nitrate NH3).
Commercial value of N-P-K is determined by the alternative source of these nutrients as purchased from your local co-op. For the sake of this discussion we will assume that your local cost per pound of nutrient is:
Nitrogen (N) . . . . . . . . . . . . . 70¢ per pound
Phosphorus (P) . . . . . . . . . . . 63¢ per pound
Potassium (K). . . . . . . . . . . . 47¢ per pound
In addition, your expected corn crop (180 bushel/acre corn) fertility needs per acre are:
N - 240 lb, P - 100 lb, K - 240 lb / Acre
(Based on Crop Nutrient Utilization Needs as found on page 20)
And if your liquid dairy effluent has a N-P-K value of:
Total Nutrient Availability per 1000 gallons = N - 24 lb, P - 27 lb, K - 6.8 lb.
First Year Availability of Nutrients = N -13 lb, P - 19 lb, K - 6 lb / Acre
(Based on actual lab report of Dairy Effluent as found on page 19)
And you choose to apply the effluent so that you are meeting your first year Nitrogen needs. Then your agronomic application rate would need to be 19,000 gallons per acre.
(240 N fertility needed / 13 lb First Year N of effluent/ 1000 gallons = 19,000 gallons)
So the total N-P-K applied based upon application rate would be:
(Based upon 19 times the 1000 gallon N-P-K values of effluent)
N - 247 lb, P - 361 lb, and K - 114 lb / Acre
(Additional 218 lb. Organic N and 152 lbs of P available in future years; Short 126 lbs of K for present year)
Then the relative value of the effluent product would be as follows:
Fertility Needs Manure Applied
Nitrogen (N) (Current Year N) .70 x 240 = $168 .70 x 247 = $173 Future Value Organic N $ 0 .70 x 218 = $152
Phosphorus (P) .63 x 100 = $ 63 .63 x 361 = $227 (Excess of 413 lb P)
Future Value Phosphorus (P) $ 0 .63 x 152 = $ 96
Potassium (K) .47 x 240 = $113 .47 x 114 = $ 53 (Need 126 lb more K)
Micro Nutrients & Humus $ 0 $ ???
Application Costs $ 8 $ 0______
Total Value $354/Acre $701/Acre
In the above example you are Phosphorus loading the soil (513 lb. Total Phosphorus applied minus 100 lb. Phosphorus needed by crop = 413 extra pounds of Phosphorus over agronomic needs) while needing an additional 126 pounds of Potassium. Generally a farmer is only willing to pay the maximum of the commercial fertility costs he would otherwise be paying for that years crop or in this example $286.78 per acre. ($286.78 = $354 comparable fertility costs less $67.22/acre needed for phosphorus supplemental application).
You are giving lots more value to the farmer in the Organic Nitrogen that will be available in future years; while this has value to the farmer it is usually not in the current years budget. This future value of organic Nitrogen and Phosphorus is negotiable in several ways: a) maybe a percentage of the future value paid now, or; b) residual payments in future years based upon retained fertility in the soil samples, or; c) simply given to farmer as a bonus and enticement to pay the current useable N-P-K value provided.
Assuming the application and pumping costs for 19,000 gallons per acre (based upon % solids, distance to field, fuel costs, mobilization costs, etc.) then a rough estimate of pumping costs could be $228 per acre. In this example, if you are farming your own land then the manure has full value of $701 and the fertility value received more than pays for the pumping costs.
If you are a CAFO and are not farming any land then you could sell or export the product to a nearby farmer for the commercial value of the current years fertility needs delivered or in this example $287. In the export situation you would be giving the farmer excess value of $673 and you as the manure producer wouldn’t need to pay anything for having your lagoon cleaned. Historically a farmer is not willing to pay for the pumping costs unless the nutrient value far exceeds the fertility value. In most cases the farmer is willing to pay a percentage of the going commercial rates.
Another way of share costing the pumping and application costs is for the CAFO manure producer pays ½ of the pumping costs and the farmer pays the other ½ of the pumping costs. In this scenario the farmer would be getting extreme value and at least the CAFO or lagoon owner would receive some financial help to offset the lagoon cleanout costs.
In some commercial, industrial and municipal lagoons, which have low N-P-K nutrient values, the only way to dispose of the effluent is to give the product to the farmer and for the waste producer to generally pay the full cost of the pumping or lagoon cleanout.
The fertility value is proven to the farmer by the lab reports of the samples taken of the product delivered to his field. It is recommended that a sample be taken for every field or 40 acre track.
If your operation is in a state that requires the agronomic application rates to be for Phosphorus levels then the application rate would need to be much less and the farmer would have to supplement their Nitrogen and Potassium fertility with commercial fertilizer from the co-op.
Value of Manure Links to Active Calculators