Radiometric density measurement for silage compaction in bunker silos

Certain minimum densities should be targeted when storing silage in bunker silos.  However, farmers lack facilities to measure the actual density and then steer the compaction passes. This study was aimed at develop ing a measuring device for onsite density measurement.  The basis of the measuring device was a source of caesium radiation with an activity of 37 MBq and a sodium iodide scintillation detector.  The measuring device used the backscattering method.  The source and detector were located in a measuring wheel that was connected with the tractor via the rear three-point linkage.  During measuring passes on bunker silos both the density increase in the case of several crossings a nd the elastic recovery of the material could be seen clearly.  In connection with satellite-based position determination, the silo surface can be mapped according to density.  As a result of the random decay of the caesium, the error in density measurement was only ± 4% at 600 kg m -3 . Keywords: silage compaction, bunker silo, silage density, radiometric measuring device