Manure

The application of animal manure to farmland is an economically and environmentally sound management practice for most feedlot operators and farmers. Land application returns nutrients from manure to the soil and helps build soil fertility. Manure provides nitrogen (N), phosphorus (P), potassium (K), calcium, magnesium, micronutrients and organic matter. Applying manure to soil has been shown to improve soil tilth, increase water-holding capacity, reduce wind and water erosion and improve soil aeration. Land application of manure should be managed to recycle plant nutrients rather than used as a disposal method.

Producers need to be aware of the impacts manure can have on water and air quality. However, manure and other byproducts of livestock production have important impacts on farm profitability, neighbor relations and protecting soil and water quality.

Over the past couple of months, two situations within the world of animal nutrient management have come back into the limelight, forward movement of the EPA on monitoring air emissions from various agricultural facilities across the U.S. and a new look at who is actually required to obtain a discharge permit for CAFO operations. Neither development is going to change the face of agriculture today, but as information continues to flow, there is opportunity for change in the future.

When crude oil was $10 a barrel, the benefits cow power can provide to farms, communities and the environment were a blip on the radar. Now that crude oil has surpassed $70 a barrel, interest in renewable energy is on the rise. However, biogas recovery from anaerobic digestion still takes a backseat to ethanol and biodiesel in the limelight. Experts in the energy field are beginning to shift this focus, pointing out the multiple benefits of using waste to produce biofuels.

Ammonia used to be considered only as a nuisance odor emitted by dairies and other livestock operations. Now, ammonia is known to react with atmospheric nitric and sulfuric acids to form fine particulate matter (known as PM2.5), which is a major contributor to smog production.

Dairy farms are thought to emit large amounts of ammonia, therefore contributing to nitrogen (N) fertilization of natural ecosystems and providing precursors for particulates that adversely affect air quality and human health. The 2003 National Research Council report Air Emissions from Animal Agriculture made an urgent call for processed-based research to assist livestock producers and regulatory agencies in developing strategies that reduce the emissions of ammonia and other gasses that impair air quality.