Independent Science for Animals, Farms and Ecosystems.
What Is Your Dairy Manure Really Worth?
Alvaro Garcia, DVM, PhD
Global Farming Digest
Abstract
High fertilizer prices increase the potential economic value of dairy manure, but nutrient content alone does not determine what manure is worth. Its fertilizer replacement value depends on nutrient availability, soil fertility, application timing, and the cost of transporting and applying it. Using 2026 fertilizer prices, this article demonstrates a practical method for valuing dairy manure based on available nitrogen, phosphorus, and potassium. An example dairy slurry provides approximately $18.39 per 1,000 gallons in first-year N-P-K replacement value when all three nutrients are needed, but that value declines when the receiving field requires fewer nutrients. The DAIRYNOMICS approach emphasizes manure testing, soil testing, nutrient conservation, and field-specific valuation to determine the fertilizer purchases manure can realistically replace.
Introduction
With currently high fertilizer prices, the nutrients leaving a dairy barn are becoming increasingly valuable. Yet manure is still often viewed primarily as something that must be stored, hauled, and spread rather than as a fertilizer resource with a measurable economic value. Putting a price on manure starts with a simple question: What would it cost to replace its nutrients with commercial fertilizer? The answer, however, requires more than multiplying the pounds of nitrogen, phosphorus, and potassium in a manure analysis by fertilizer prices. Nutrient availability, soil fertility, application method, and hauling costs all determine how much of that theoretical value the farm can capture.
Start with fertilizer replacement value.
At the end of August 2026, average U.S. retail fertilizer prices reported by Data Transmission Network (DTN) were approximately $655/ton for urea, $918/ton for diammonium phosphate (DAP), and $493/ton for potash. Fertilizer prices vary by region and purchasing time, but these values provide a useful example.
Converted to individual nutrients, urea at $655/ per U.S. short ton (2,000 lb) is worth approximately $0.71/lb of N. After accounting for the nitrogen supplied by DAP, phosphorus is worth approximately $0.72/lb of P₂O₅, while potash at $493/ton provides K₂O at approximately $0.41/lb
These are not fixed DAIRYNOMICS values. Producers should substitute the fertilizer prices they can obtain. As fertilizer prices change, so does the fertilizer replacement value of manure.
What is 1,000 gallons of dairy manure worth?
The best place to start is a representative manure analysis because nutrient concentrations vary with diet, water use, bedding, storage, separation, and manure handling. Book values are useful for illustration but should not replace testing when real dollars are involved. For our example, consider dairy slurry that, after accounting for first-year nutrient availability and incorporation within one to three days, supplies approximately 10 lb of available N, 6 lb of P₂O₅, and 17 lb of K₂O per 1,000 gallons. Using our fertilizer values:
At an application rate of 10,000 gallons per acre, this represents approximately $184/acre in first-year N-P-K fertilizer replacement value, provided the field needs all three nutrients.
The field determines the value.
Suppose soil testing indicates that the receiving field needs nitrogen and potassium but no additional phosphorus. The phosphorus in the manure has not disappeared, but it does not replace a phosphorus fertilizer purchase the farmer otherwise would have made. The immediate fertilizer replacement value therefore falls from $18.39 to $14.07 per 1,000 gallons. If the field needs only nitrogen, the immediate fertilizer replacement value falls to $7.10. The same manure can therefore have quite different economic values depending on where it is applied.
This makes field selection part of manure economics. When several fields are available, directing manure toward those with the greatest nutrient demand can capture more of its fertilizer replacement value. Applying manure where nutrients are already adequate may satisfy a disposal need, but it does not necessarily generate the same fertilizer savings. Distance also enters the decision because reaching a field with greater nutrient demand may require additional hauling.
This is particularly important in fields with a history of repeated manure application. Soil phosphorus or potassium may already be adequate or high, while the crop still requires nitrogen. Assigning full fertilizer value to nutrients that would not otherwise have been purchased overstates the immediate economic benefit of the manure.
“A nutrient has full fertilizer value only when it replaces a nutrient the farm would otherwise purchase”.
Protect the nitrogen you already have.
Nitrogen presents another challenge because total manure nitrogen and crop-available nitrogen are not the same thing. Part of manure N is organic and must mineralize before plants can use it, while ammonium N can be lost to the atmosphere after application.
Application method and timing therefore have an economic consequence. Wisconsin nutrient-management guidelines estimate 7 lb of first-year available N per 1,000 gallons of dairy slurry when incorporation is delayed more than three days, compared with 10 lb when incorporated within one to three days and 12 lb when incorporated within one hour.
At $0.71/lb of N, increasing available N from 7 to 12 lb captures another $3.55 per 1,000 gallons. At an application rate of 10,000 gallons per acre, that represents approximately $35.50/acre in additional fertilizer replacement value.When manure nitrogen is lost, fertilizer value leaves with it.
Gross value is not net value.
Knowing what the nutrients are worth is only part of the calculation. Manure also must be stored, pumped, hauled, and applied, and liquid dairy manure contains a great deal of water that becomes increasingly expensive to transport as distance increases.
The relationship can be expressed simply:
Gross fertilizer replacement value = Value of available N + Value of usable P₂O₅ + Value of usable K₂O
Then net manure value at the field = Gross fertilizer replacement value − incremental hauling and application costs
The word incremental is important here. A dairy may have to manage and apply manure regardless of whether its fertilizer value is recognized. Charging every unavoidable manure-management expense against the nutrients can therefore understate their value. The relevant cost is the additional expense associated with delivering and using the manure in the field being evaluated.
This also explains why manure does not have one universal price. A nearby field that needs N, P, and K may capture substantial fertilizer value. The same manure hauled farther to a field that needs only nitrogen may be worth less after transportation and application costs are considered.
Test it before you price it.
A manure analysis may be one of the least expensive steps in valuing a resource that represents thousands of dollars annually. Using book values for a DAIRYNOMICS example is reasonable; using them to make major fertilizer decisions when a manure analysis is available is not.
Testing establishes what is in the manure. Soil testing establishes what the field needs. Current fertilizer prices establish what those nutrients would cost to replace. Together, those three numbers transform manure from a waste-management expense into a resource that can be evaluated economically.
There may also be value beyond N, P, and K. Manure supplies organic matter, sulfur, micronutrients, and potential longer-term soil benefits. These benefits are real, but they are more difficult to price consistently and should not be used to inflate the immediate fertilizer replacement value.
High fertilizer prices increase the potential value of dairy manure, but they do not make every pound of manure nutrient equally valuable. What matters is how much of that nutrient is available, whether the receiving field needs it, what commercial fertilizer it replaces, and what it costs to deliver it there. The economic value of manure is determined by the fertilizer purchase it can replace on a specific field.
Further reading
1. García, Alvaro. 2026. “Treat Manure as a Nitrogen Asset.” Journal of Nutrient Management, May 2026, 12–13.
https://dellait.com/insights/treat-manure-as-a-nitrogen-asset/
2. Ramos Tanchez, Juan Carlos, et al. 2025. “Manure Continues to Offset Nitrogen Fertilizer Needs and Increase Corn Silage and Grain Yields: Value of Manure Project 2024 Update.” Cornell University Nutrient Management Spear Program.
3. Irias, Carlos, Quirine M. Ketterings, Juan Carlos Ramos Tanchez, and Kirsten Workman. 2023. “Quantifying the Value of Manure: Taking Uncertainty Out of an Inherently Variable Nutrient Source.” Progressive Dairy, November 25, 2023.
4. University of Wisconsin-Madison Division of Extension. Nutrient Application Guidelines for Field, Vegetable, and Fruit Crops in Wisconsin.
https://cropsandsoils.extension.wisc.edu/files/2024/10/Fast-Facts-2025_