Emissions of NH3, N2O and CH4 from composted and anaerobically stored farmyard manure

A large open-dynamic-chamber has been developed and is now used to asses the emissions from all sectors of animal husbandry. It covers an area of 27 m2 and can be built up over different emitting surfaces or manure heaps. It enables emission measurements of up to 8 t of manure under practical conditions. The compost emitted more NH3 (823 g/t) than the anaerobically stored solid manure (287 g/t). The NH3 emission from the compost amounted to about 10% of the total nitrogen content of the fresh manure. Half of the total emissions of the anaerobically stored solid manure was emitted after spreading. The compost did not emit any NH3 after spreading. The results show the importance of measuring emissions during storage as well as during and after spreading, if emissions of different treatments are to be evaluated. Anerobically stored solid manure emitted much more greenhouse gases (N2O : 74.7 g/t and CH4 : 1493.8 g/t) than the compost (N2O : 49.8 g/t and CH4 : 151.1 g/t). If environmentally friendly manure management systems are to be found, it is n ot sufficient to measure only one gas. The emissions of NH3, CH4 and N2O have to be considered and reduced. / Les émissions gazeuses sont mesurées à l'Institut d'Ingénierie pour l'Agriculture et l'Environnement (ILUET) à l'aide d'une chambre ouverte dynamique qui couvre une surface de 27 m². Cette chambre permet de mesurer les émissions issues de tas de plus de 8 t. de produit. Le fumier composté émet davantage d'NH3 (823 g/t) que celui géré de façon anaérobie (287 g/t). Le fumier géré en conditions anaérobies émet davantage de gaz à effet de serre : N2O : 74.7 g/t et CH4 : 1493.8 g/t que celui composté : N2O : 49.8 g/t et CH4 : 151.1 g/t.