Manure Manager

Air quality, economics the focus of dairy project on ammonia

March 31, 2008  by Manure Manager

Cow manure is the most inexpensive source of fertilizer for dairy farms.

Cow manure is the most inexpensive source of fertilizer for dairy farms. The question for farmers is how to gain the crop nutrient benefits from manure while reducing the loss of ammonia-N (nitrogen) into water and air. Learning the answer before the government initiates new regulations is one of the objectives of a project funded by the New York Farm Viability Institute to evaluate the potential of ammonia-conserving manure management practices.

“New York’s farmers are addressing ammonia-N loss for both environmental and economic reasons,” said Ammonia Air Emissions project leader Shawn Bossard.
“The loss of plant-ready nitrogen through ammonia volatilization (liquid becoming gas) easily equates to $100/acre in lost crop nutrient value. Economically, the more manure-based nutrients we can feed into our soil for crops, the less money farmers have to spend to buy fertilizer. The surrounding environment benefits, as more nutrients are kept in the soil and less ammonia is lost into the air.”

The US Environmental Protection Agency may soon look more closely at field losses of ammonia into airsheds—geographic areas of atmosphere that affect nearby water bodies. Although airborne nitrogen in the form of ammonia is lighter than air, eventually ammonia-N rises, combining with other particles, and falls to ground or water surfaces. Excesses of nitrogen in water can lead to algae bloom that creates low oxygen conditions for aquatic plants and animals.


Bossard, executive director of Cornell Cooperative Extension of Seneca County, says dairy farms in Europe are restricted to a specified amount of ammonia release. The Netherlands, for example, has a zero ammonia air emissions standard. Manure must be injected into field soils and all manure storage is covered there.

“Here in the US and New York, farmers managing for ammonia loss are incorporating manure into soils to reduce run-off and air emissions. Farmers using a manure injection system may see as much as a 50 percent reduction in nitrogen costs per field,” Bossard said, “and may also benefit from an equal reduction in phosphorus, an excess of which can lead to algae bloom in nearby water. Better utilization and containment of nutrients will positively impact the long-term use of farm fields.”


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