Experimental subsoiling by in-line shallow and deep tines

Conventional soil ripping has high fuel consumption because it involves high draft force and may produce large soil clods. This experiment compares the use of shallow leading tines ahead of the main tine with use of a conventional single-tine ripper. The study showed that attaching a single, shallow leading tine ahead of, and in line with, the main tine and 25-40% shallower in depth gave the greatest significant decrease in specific draft force. This led to a fuel reduction from 13.6 to 11.5L/ha, or a saving of 15% when ripping a moist loamy sand soil to 330mm depth. Attaching more than one shallow lead tine ahead of the ripper did not significantly affect specific draft forces, whether the shallow lead tines were in line or offset. Other advantages of using the shallow leading tine ripper over the conventional ripper are: improved soil tilth by significantly decreasing soil clod size; potentially a wider moisture range for ripping the soil (as soil clods are smaller and drier soil increases clod size) thus increasing the time available for the operation; and decreased depreciation of ripping components.