Put more nitrogen into milk, not manure

May 28, 2010

The more efficient dairy farmers are in managing nitrogen, the more milk their cows will produce and the less nitrogen will be wasted in manure and urine, according a study by Agricultural Research Service (ARS) scientists and cooperators.

ARS soil scientist J. Mark Powell at the U.S. Dairy Forage Research Center in Madison, Wis., worked with ARS agricultural engineer Clarence Rotz at the ARS Pasture Systems and Watershed Management Research Unit in University Park, Pa., and Australian colleagues to calculate use efficiency ratings to guide dairy farmers.

These new efficiency ratings could help dairy farmers make better use of their nitrogen in the face of escalating costs and increasing nutrient regulation. Farmers feed nitrogen in the form of crude protein to their cows, and apply and to grow crops and pasture for cows to eat and convert to milk.

The scientists found that only about 20 to 35 percent of the nitrogen fed to dairy cows is converted into milk. They also discovered that 16 to 77 percent of the nitrogen in manure or fertilizer is necessary for grass and other pasture plants. And their study showed that between 8 and 64 percent of all the nitrogen applied to typical commercial dairy farms is converted into farm products.

They determined the whole farm nitrogen use efficiency by applying the ARS-developed Integrated Farming System Model on two typical dairy farm types in Wisconsin. They used the model to quantify the effects of numbers of cows per acre and manure nitrogen credits (reducing fertilizer nitrogen applications when manure is applied) on nitrogen use, farm profitability, and pathways of nitrogen loss.

The wide ranges in nitrogen use efficiency point to the fact that there is significant room for improvement by using various practices that improve nitrogen use, profits, and the environment. Nitrogen use efficiency formulas can be used as tools to promote practices that maximize nitrogen use so that nitrogen does not leave farms to pollute waterways and ground water and negatively impact air quality.

From these tools, which are effectively a nitrogen efficiency audit, may come recommendations to dairy farmers, consultants, and policy makers.

Explore further: Spain defends Canaries oil drilling plan

More information: This research was published in the Environmental Science and Policy Journal.

Provided by United States Department of Agriculture

4.8 /5 (4 votes)
add to favorites email to friend print save as pdf

Related Stories

Improving swine waste fertilizer

Jul 08, 2008

Swine production generates large amounts of waste. While this waste contains nutrients that may serve as fertilizer when applied to agricultural fields, the ratio of nutrients in the waste is different than what a crop requires.

Nitrogen applied

Oct 01, 2008

Combating soil erosion is a primary concern for agricultural producers in the United States, and many have incorporated conservation tillage systems in their effort to maintain a profitable crop output.

Alternative farming cleans up water

Jul 19, 2007

Although the addition of nutrients to soil helps to maximize crop production, fertilizer can leach nutrients, polluting the water supply. A recent study by researchers at the University of Minnesota shows alternative cropping ...

How much nitrogen is too much for corn?

Apr 23, 2007

North Carolina State researchers recently discovered a test that quickly predicts nitrogen levels in the humid soil conditions of the southeastern United States. These scientists report that the Illinois Soil Nitrogen Test ...

Recommended for you

Study shows no lead pollution in oilsands region

15 hours ago

New research from a world-renowned soil and water expert at the University of Alberta reveals that there's no atmospheric lead pollution in Alberta's oilsands region—a finding that contradicts current scientific ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

Quantum_Conundrum
2 / 5 (1) May 28, 2010
The atmosphere of our planet is 78% nitrogen, ya morons.

You think changing a cow's poop by 5 or 10% is really going to make a difference? That's insignificant compared to all the animals in nature, and compared to what's in the atmosphere being filtered by plants and oceans to begin with.

These people need real jobs, I swear this is pointless...
PPihkala
5 / 5 (1) May 29, 2010
They are talking here about bioavailable nitrogen, and there atmospheric one normally does not count. Want to make a bigger dead zone at deltas of rivers? Then make sure that your nitrogen at field get's washed to rivers. Or rather not, which promotes good nitrogen handling and use.
ormondotvos
not rated yet May 29, 2010
How much nitrogen in a human body? That first comment got me to wondering...