Most dispersion models have originally been developped to describe odour dispersion pattern from industrial source pollutants. In agriculture, most of the odour sources are at or near ground level, there is generally no plume rise developping, the source may differ a lot from point-source and be of large areal extent, the emission source may be relatively close to the receptor zone, the odour emission rate is difficult to measure (not a single pollutant component), the emission rates can vary in time and space and finally the emissions can be of relatively low intensity. Adaptations have to be done to the model curently used to take into account these agricultural factors.