Abstract
The design of a hydraulically powered soil core sampler used to collect undisturbed soil samples at different depths in the field is presented. The hydraulic actuation of the coring probe reduces the physical effort and time required by the operators. The device is constructed from a three-point hitch frame equipped with a gearbox, retractable legs, hydraulic cylinder and probe. The legs are driven from the tractor power takeoff shaft through a gearbox that can change the direction of rotation of worm gear shaft. The worm gears drive power screws that extend the legs to hold part of the tractor weight. The tractor auxiliary hydraulic power actuates the cylinder to push the probe into the soil. The device was tested in the field successively to collect soil samples for physical properties measurements. The results from the field compaction study of the hydraulically powered soil core sampler confirmed that the system could rapidly collect soil cores for measuring soil properties. Changes in soil physical properties caused by a KUBOTA M8030 tractor with 18.4 R30 tires at 100 kPa with a loaded 1500 kg seed drill mounted on the tractor were measured for soil samples obtained by the soil core sampler and by the manual sampling method. The bulk density and total porosity data from this field experiment showed that significant effects were present down to a depth of 50 cm. In addition, the results obtained using the soil core sampler were close to those obtained by the manual sampling method.