A system for the real-time geo-referenced measurement of soil parameters

The aim of this research is to develop a system for accurately measuring in real-time, collecting and processing a high amount of geo-referenced data of soil physical-mechanical parameters, e.g. cone penetrometer resistance, index of soil compaction, and draft force. The system for measuring the soil cone penetrometer resistance is comprised of a load cell, connected to a rod, ending with a cone, and is mounted on a frame, fixed to the front part of a tractor. The system for measuring the draft force required to till the soil is comprised of a load cell, mounted on the hitch hook of a tool carrier, towed by the tractor. Moreover, in order to test the usefulness of the system with different types of linkage tractor-implement, two other load cells were mounted, respectively, on the top link and the right point of the three-point hitch of the tool carrier. A portable computer, by means of a Virtual Instrument, developed in LabVIEW environment, acquires the signals of the load cells and of a DGPS mobile receiver. The results of the first tests, carried out in a field in inland Sicily, showed that: the system is able to log data with a sampling frequency adjustable from 1 to 10 Hz; it is able to accurately measure and collect in real-time a large amount of data, which can be easily processed by means of a data sheet, a GIS or another software usable for measuring the within-field spatial variability of soil physical-mechanical parameters; the absolute value of the force measured on the hitch hook of the tool carrier is proportionally correlated to that measured on any point of the three-point hitch of the same one.