A SYSTEM FOR MEASURING SOIL PHYSICAL-PROPERTIES IN THE FIELD

An automated soil sampler and a system for measuring the physical prop erties of soil cores in the field were developed for the study of soil compaction and tillage effects on soil physical properties. The syste m measures the bulk density, air-filled porosity, intrinsic air permea bility, and moisture content on 47.6 mm diameter soil cores as well as measuring cone penetration resistance in the field. Results of a labo ratory calibration study illustrated that the system measures the soil properties with acceptable accuracy. A main benefit of the system was the fact that it could measure all of the above properties on ten cor e samples down to a depth of 0.5 m, typically within 15 min. A field c ompaction study showed that the system was capable of detecting the ef fects of a 15.2 tonne axle load on the soil down to a depth of 0.4 m, 1 year after compaction.