Comparison of sampling methods for animal manure

Abstract

More stringent legislation on undesirable mineral losses to the environment at the farm level creates the need for the farmer to obtain accurate information on the mineral flows at his farm, including the mineral content of manure. Both currently available and recently developed new sampling methods for slurry and solid manure were tested for bias and reproducibility in the determination of total phosphorous and nitrogen content of the samples. Sampling methods were based on techniques in which samples were taken either during loading from the hose or from the transporting vehicle after loading. It was demonstrated that most methods were unbiased. New methods for slurry, based on sampling from the hose, were up to a factor two better reproducible compared to existing methods. Sampling of solid manure can be done accurately in a relatively simple way. For practical reasons mechanisation of sampling is desirable. To minimize the influence of human activity on the quality of the sample automatization is strongly advisable.