The production and composition of horse manure was studied with on farm experiments as well as balance calculations. The results should provide the basis of the revision of the corresponding guide values. Balance calculations were done for riding horses, mares and colts of different age. Animal weight, amount of straw used for litter and hours of activity (riding, work) were used as additional variables. The thus calculated excretion was lower for all categories than according to today’s guide values. The annual production per adult horse was 12-13 t of fresh or around 6 t of decomposed horse manure. The content of the horse manure was influenced more by housing system and straw use than by the different horse categories.
Symbiotic nitrogen fixation by bacteria in the soil coexisting with legumes leads to reduced fertiliser requirement. It is not easy to measure this variable on farms, however. Now researchers from Agroscope have developed a method for estimating nitrogen input via symbiotic fixation at farm level.
With increasing global and regional temperatures, even in Switzerland the growing season has lengthened considerably. Using data from the Federal Office of Meteorology and Climatology, Agroscope has traced the development of the growing season since the start of the previous century.
The phosphate mineral reserves required for fertiliser production could be exhausted on a global scale in just a few decades. This study presents a method for recycling a Swiss industrial by-product into a phosphate fertiliser.