Reliable estimates of ecological impacts of agriculture require a detailed knowledge of farm management and structure. To establish a new Swiss ammonia emission inventory, a representative survey on parameters relevant for ammonia emissions was conducted in 2002. The stratified sample of farms allowed the differentiation between nine different regions and four farm types. The results of this survey allow to analysis regional differences in farm and manure management as well as changes in time. The majority of the Swiss dairy cows is grazed between 151 and 230 days per year and for five to twelve hours per day. Labour extensive slurry systems have gained in importance for dairy cows since 1990. During the same time, the proportion of the animals held in loose housing systems increased to 25% for dairy cows and to 47% for heifers. At the national scale, about 80 % of the slurry is stored in covered stores, and 11% is spread with low emission band application systems. Over 80% of the slurry and about halve of the solid manure is spread on grassland. In pig production, reduced protein feed is mainly used in regions with high livestock density and on specialised larger farms.
Farm and manure management in Switzerland