There is not much knowledge about pharmaceutical residues in Norwegian horse manure. In this project we have further developed a method that enables the analysis of various antibiotics and anthelmintics in a single sample. The method is designed for the analysis of solid substrates, such as horse manure. Manure from treated horses and horse manure with additions of controlled amounts of medicines were composted outdoors in a windrow consisting of horse manure and freshly cut grass. In a pot trail earthworms were added to some of the manure from the treated horses to study the effect of worm action on the biodegradation of pharmaceutical residues. - At the start of the project, several veterinary medicines were considered. The developed analysis method covers several active ingredients in the most commonly used equine medicines. The antibiotic Tribrissen vet inj with the active ingredients sulfadiazine and trimethoprim, and the equine anthelmintics Panacur (active ingredient fenbendazole) and Banminth (active ingredient pyrantel embonate) were included in the entire preliminary study. In total, 70 samples of horse manure and horse manure compost were analysed. We found that dried manure from treated horses could be analysed directly, thus making it unnecessary to freeze-dry samples prior to sending them further for analysis. The method can be used to analyse all four active ingredients at the same time. - Contents of pharmaceutical residues in horse manure are highest 1-2 days after the horse has been treated, with some variation between substances. After this peak, residue contents in manure decrease rapidly. Degradation of the added medicines was slow in the composting trials. In the compost windrow, the contents of medicines decreased gradually throughout a 60-day period, with slightly different degradation curves for the various substances. Three of the tested active ingredients were still detectable in the compost after 60 days. The earthworm trials have to be improved and repeated, among other things, because many worms died in the untreated horse manure plots. - Our trials show that manure from treated horses should be kept apart from other manure for the first 1-3 days after medical treatment. Strategies for the management of such manure have to be developed so that this resource can be used safely in plant production. Additional studies are needed to assess the degradation rate of pharmaceutical residues using different composting methods. Important factors that need to be studied in greater detail under Norwegian conditions include temperature development, windrow dimensions, moisture conditions and earthworm survival. We did not study the contents of pharmaceutical residues in urine. - We performed a survey on soil and fertilizer products among 100 garden centre customers. The results showed that there is a certain interest for peat-free, locally produced soil and fertilizer products. Approximately half of the respondents replied that they are willing to pay as much as 20 % more for such products. Consumers preferred soil amendments that contain nutrients and are typically ”all-purpose”, i.e. a single product that can be used across a wide range of applications. - This project has been important for the project partners due to its development of an analysis for pharmaceutical residues in solid horse manure. Furthermore, it provided a basis for the further development of horse manure as a pharmaceutical residue-free product.