Technical measures to reduce ammonia losses after spreading of animal manure

During the years 1992-1995, field trials were conducted at the Swedish Institute of Agricultural Engineering (JTI) to investigate the efficiency of different techniques to reduce ammonia emissions after spreading of liquid and solid manures (i.e. slurries and farmyard manures). Ammonia emissions were measured with passive diffusion samplers. Results clearly show that the most effective way to reduce ammonia emissions is to inject or incorporate the manure into the soil. When applying slurry in a growing crop, band spreading gives a lower emission than broadcasting. Irrigation after spreading also reduces ammonia emissions. Solid manure can give rise to substantially greater ammonia emissions than slurry when applied at the same rate under identical environmental conditions and should not generally be considered as a low-concentrated N fertilizer.