PROJECT DESCRIPTION
BACKGROUND
The ecological systems of Europe are polluted by nitrogen. The single largest source is ammonia emissions in agriculture, mainly from manure excreted by livestock. The emissions contribute to acidification and eutrophication of forests, lakes and watercourses. Since ammonia has a much shorter spreading range than other airborne pollutants, there are good possibilities for each individual country to reduce its own ammonia problem. However, the emissions of Europe have not declined to any greater extent in the last few decades.
OBJECTIVES
The objective of the project was to demonstrate an efficient and innovative combination of methods to reduce ammonia leakage on the dairy farm level and to increase knowledge in this field among authorities, farmers, extension workers and agricultural students in Sweden and Europe. The project covered the area of responsibility of the farmer. For this purpose, an existing cow-house with 42 cows in traditional tie-stalls and solid manure handling was re-designed and ammonia losses from the cow-house and during storage and spreading of manure was recorded before and after re-building.
RESULTS
The project demonstrated the possibilities of reducing ammonia emissions from a typical Swedish milk producing farm. The reduction of ammonia losses was achieved by: (1)Improving the nitrogen efficiency in milk production. (2)Creating indoor climate and conditions that reduced ammonia release from the cow-house. (3)Binding the ammonia in the outgoing air from the cow-house in a bio-filter. (4)Storing slurry in a covered container; and (5)Using the best available techniques for spreading manure. Total ammonia emission from the farm was reduced by 66%, when the effect of the bio-filter was included. Without the inclusion of the bio-filter the reduction was 48%. The following conclusions can be drawn from the project: - A nitrogen efficiency close to 31% is realistic for lactating cows at traditional Swedish dairy farms, using grass silage and concentrates, possibly with some dried sugar beet pulp (Betfor) added; - The protein concentration 160-170 g/ kg DM is realistic for cows in early lactation. This concentration has the potential to increase milk production and at the same time reduce the losses of ammonia from the manure. The better the management and follow-up of production is, the lower the protein content can be; - Increased individual milk yield improves the nitrogen efficiency; - Slurry handling offers several possibilities to reduce the ammonia emission during storage and spreading of the manure; - When building or expanding a cow-shed it is important to include a storage of slurry big enough to allow for spreading at optimal time-points and under good conditions; - A cover on the slurry or urine storage container reduces the ammonia losses effectively but at a relatively high cost. There are less expensive alternatives, but these might require more attention and maintenance; - Band spreading and shallow injection of manure may be used in different crops and, normally, keep ammonia losses at a low level. At the same time the unpleasant odours from the spreading are minimised. Control of the slurry application rate also limits contamination of plants. - The changes implemented at the project farm improved the Farmgate nitrogen balance. More of the nitrogen in the slurry was utilised and thus less mineral fertiliser was needed. Within the frame of the Swedish governmental goal to reach the targets set in the 15 “Swedish Environmental Quality Objectives” regional and local programs for reduction of ammonia losses have been worked out. Almost 4,000 farmers have joined the advisory service Greppa Näringen, and stricter rules for storage and spreading of manure will be enforced. The project Life Ammonia certainly contributed to focus on one of the environmental problems and to demonstrate on the possibilities to achieve improvements. Environmental benefits The major reduction of ammonia losses from the project farm came from storing and spreading of manure. The new slurry system made it possible to apply manure to growing crops in the springtime. Assuming that 25-50% of the result achieved in the project could by applied to the about 400,000 Swedish dairy cows, the total emission in Sweden would decrease with 2,000 - 4,000 tons nitrogen in ammonia per year. This would correspond to 27 – 55% of the total reduction of 7,300 tons, aimed at in the goals set by the government. Any dairy farmer with a stanchion barn or loose housing can easily adopt the feeding strategy used in the project. Most likely the nitrogen efficiency in milk production in Sweden is closer to 25% than to 30%. Calculations indicate that for each 2 percent unit increase in nitrogen efficiency in milk production the total ammonia losses from dairy farms in Sweden would be reduced by 500 – 1700 ton ammonium nitrogen per year, which would correspond to 7 – 23% of the total target 7,300 ton per year. . A follow up ex-post evaluation, carried out in June 2004, by the LIFE external monitoring team showed the project work continues, despite formal closure. A new campaign “Greppa Näringen” has been launched providing an advisory service on regional and local programmes to help reduce ammonia losses. (Almost 4,000 farmers have joined this advisory service.) An important tool in maintaining the impact of the project is the website, which continues to be regularly updated. It will shortly be fully incorporated into the university’s website at: www.slu.se/. It also has a key role to play in promoting the follow-up “Greppa Näringen” campaign. Former project staff members Jan Hultgren and Jan-Olof Sanno are still involved in updating the website and in the campaign’s activities aimed at farmers. They also continue to disseminate the project results. For example, a study entitled: “Techniques to Reduce the Ammonia Release in a Cowshed with Tied Dairy Cattle”, (J. Hultgren, J-O Sannö, et al) was published in 2004, in the internet publication: “The CIGR Journal of Scientific Research and Development”. Also in 2004, Mr Hultgren delivered a report to the ISAH (International Society for Animal Hygiene) International Congress on animal production in Europe, held 11-13 October in Saint-Malo, France.
