Got cows?  Then you’ve got manure. your average cow will produce approximately 150 pounds of manure every day, depending upon her diet. And, every pound of manure contains the nutrients nitrogen, phosphorous and potassium.

Commercial fertilizer also contains these three nutrients. And, no one needs to tell you that the price of fertilizer has increased dramatically — in some cases, tripling its value in a year’s time. Fertilizer that was $300 in August of 2007 sold for $1,200 in August 2008, says Martin Bianchi, fertilizer-purchasing coordinator with Stanislaus Farm Supply in Modesto, Calif. 

This price increase is the result of many things, says Pat Kiernan, fertilizer-pricing coordinator for Western Farm Service in Stockton, Calif. “Fertilizer is a global market, and developing countries are using more commercial fertilizer,” he explains. The lower value of the dollar against other currencies allows these countries to compete at higher levels, and they are willing to spend more for fertilizer. Higher energy prices are only a small part of the equation.

A marketing opportunity

The increase in fertilizer prices presents an economic opportunity for you. Despite arguments that manure is a waste-stream, or that you don’t have time or money to invest in managing it, there are profit-making options for every size and type of dairy.

The value of manure has been underrated for way too long, says Warren Hutchings, environmental-compliance specialist with Innovative Ag Services in Tulare, Calif. “As the price of commercial fertilizer continues to increase, utilizing manure as fertilizer becomes more attractive,” he says.

In some cases, commercial fertilizer can be completely replaced by manure. If you are looking to do this, it is important to know the nutrient content of both the manure and the nutrient content of the soil where it will be applied.

“But, if you are able to replace commercial fertilizer, you could realize a huge savings,” says John Lory, environmental-nutrient-management specialist with the University of Missouri.

Run the numbers

According to this chart from the University of Arkansas, a cow’s manure can be worth as much as $435 per year. 

Nutrient content of manure per cow per year

223-260 lbs. Nitrogen @ $.95/lb


Nitrogen = $212 - $247


40-69 lbs. Phosphorous @ $1.01/lb


Phosphorous = $40 - $70


88-146 lbs. Potassium @ $.81/lb


Potassium = $71 - $118


Total value


$323 - $435/cow/year
potential value



Nutrient content may vary depending upon the volume of manure produced on individual dairies.

Keep in mind that only 40 to 50 percent of the total value of nutrients will be available to the soil as some nutrients will be lost in storage and application. Losses are primarily due to nitrogen volatilization. About 50 percent of the total nitrogen will be available the first year as organic nitrogen and will need to be converted to inorganic nitrogen that the plant can utilize.

In addition to nitrogen, phosphorous and potassium, manure also supplies the soil with organic matter, which improves soil quality, aids in the retention of water and slows erosion. Manure carries a variety of micro-nutrients that are also beneficial to the soil.

The most accurate way to determine the nutrient contents of manure it to have it tested in a laboratory. Most soil-testing labs will test manure for a small fee.

Find the best value

Besides reducing or replacing commercial fertilizer by applying manure directly to the land, a number of other options exist, such as:

  • Separating your liquids and solids. The separated solids are high in phosphorous and the nitrogen-rich lagoon water can be used for irrigation.
  • Composting. This reduces the volume of manure by 50 percent and will also eliminate odor. You can replace bedding material with compost or use it as a soil amendment or fertilizer.
  • Anaerobic digestion of manure. Solids are broken down and methane gas is captured. Gas can be used to make electricity for the dairy, and in some cases sold to utility companies. Solids from the digester can be used for bedding. Liquids from the lagoon can be used to replace fertilizer.
  • Drag hose injection of manure.  Recent research in California has shown that injecting manure solids that accumulate in lagoons 6-inches into the soil can actually increase yields by up to 25 percent over commercial fertilizer alone.

All of these options require management. If managed properly, manure can be a valuable resource to a dairy. “I don’t think the industry has fully realized the value of manure,” says Thomas Bass, livestock environment associate specialist at MontanaStateUniversity. Income generated from manure might not be as valuable as that from milk, but it’s definitely something to consider.

New markets

Work is under way to develop new markets for manure. For example:

  • MichiganStateUniversity scientists are working on construction materials made from manure. There are several possibilities with this research, including the replacement of pressure-treated wood. Chemicals used in the production of pressure-treated wood have been banned by the U.S. Environmental Protection Agency, prohibiting the use of pressure-treated wood in playground equipment.
  • At Virginia Tech, research is under way on a product called struvite — crystallized phosphorous that has been extracted from manure. Struvite could be used as a slow release fertilizer, in the manufacturing of cleaning products, as a raw material for the phosphate industry, to make fire resistant panels or as a binding material in cement.
  • In California, milk trucks are being converted to run on biomethane captured from manure.
  • Projects are under way in other states to use compost to cover exposed soil at construction and road sites; this has proven to establish vegetation faster than hydroseeding and straw application.

“When it comes to these new markets, connecting people is sometimes the biggest challenge,” says Mark Risse, extension engineer with the animal-waste-management division at the University of Georgia. Risse is working to develop a manure-brokerage Web site to connect sellers and buyers of manure.

Rebecca Barlow, an organic resources marketer, has been working to do just that in the Shenandoah Valley of Virginia. “Our Web site has been online for seven months now, and is already gaining in popularity,” she says. Prior to creating the Web site, Barlow operated a hotline to help link buyers and sellers of manure.

There’s no doubt that manure is more valuable today than ever before. “If you have the time to manage your manure, it can have financial implications for your dairy,” says Bass.

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