Proof of concept - Oscillatory tillage in broad acre agriculture

Subsoil loosening through deep ripping improves soil porosity and soil bulk density in high strength soils and helps creating optimum conditions for root growth. Several GRDC funded projects (e.g., CSP1606-008RMX, DAW1407-004RTX, DAW1902-003RTX, UOA1703-016BLX) demonstrated that strategic deep ripping can lead to significant yield and profitability benefits, particularly on sandy soils. Nevertheless, the economics of deep ripping are an important factor when evaluating whether this amelioration strategy should be implemented on farm or not. Deep ripping is a costly farm operation, so it is vital to have significant gains to achieve a good return on investment. As estimated in previous GRDC investment UOA1703-016BLX, the costs associated with deep ripping can range from $50-60/ha for standard ripping at 50cm spacing to a depth of 30-40cm, and up to $70-90/ha for ripping at narrower spacings and/or a depth of 50-70cm, depending on machinery and soil conditions. The cost can further increase when inclusion plates are added to the ripping tines. A significant component of the cost associated with deep ripping is the fuel consumption. Draft force is the main reason for high fuel consumption, and it results from the combination of several factors such overall ripper size, tine spacing, working depth, soil moisture content, timing, soil type and more. All these factors need to be considered to maximise productivity and make deep ripping cost effective. In addition to this, the design of the tines and inclusion plates significantly affect the draft of ripping and the power requirement of the pulling tractor. Reduce draft requirement through improved design of ripping tines and inclusion plates is currently investigated in CSP1606-008RMX with promising results. Further machinery innovation for conditions specific to the Australian farming system will also be included in future investments Nonetheless, there are additional opportunities regarding improvements of machinery design for increased efficiency (both in terms of energy reduction and tillage efficacy) using active tools such as oscillatory tillage. Importantly, this research will well complement the current investment COG2302-003SAX in providing technical information for future investment.