Enhanced Integrated Nutrient Management:

Top points from Vinicius Moreira
Topic: Manure Handling and Storage Effects on Nitrogen Losses of Dairy Farms

1. Atmospheric emissions of ammonia have been related to a series of environmental and health hazards such as smog, acidic rain, particulate matter, and reduction in biodiversity.

2. Livestock emissions are amongst the most important sources of ammonia, especially those coming from ruminants. In dairy cattle production systems, nitrogen (N) will be secreted in milk, retained as body proteins, and excreted through urine and feces.

3. In dairy cows, urinary N is the most important source of ammonia volatilization, after urea is broken by the ubiquitous enzyme urease, and is influenced by many meteorological and chemical factors, such as pH, temperature, humidity, NH3 concentration and wind speed.

4. Emissions vary among dairy production systems, and their identification may lead to reduction in N losses. After a review of the literature, it is clear that it is more economic to reduce the risk of N losses by reducing the amounts of crude protein (ultimately, N) fed to dairy cows. The form of manure application to the soil should also be priority over changes in physical facilities such as barns and manure storages.

5. From a national perspective, it is important to take into consideration the density and location of animal populations. It should be stressed that the presence of more concentrated dairy production systems close to densely populated urban areas is likely to cause more serious environmental and health risk than animal production systems located in rural areas.