Strip tillage has been used extensively in North American row crop production systems including maize, soya beans, cotton and sugar beet (Morrison 2002) for the last decade. Recent changes in strip tillage implement design have seen a change from powered `rotary` implements to non-powered tine and disc implements, that are potentially suitable to work in a wider range of soil and cropping conditions than earlier designs. Strip tillage involves cultivating a strip sufficient only to establish the crop and is particularly suited to row crops such as sugar beet. The implement works directly into crop stubbles and cultivates a narrow band of soil suitable for drilling seed into. Cultivation occurs on approximately 40% of the field area leaving 60% undisturbed with the retention of crop stubble seen as advantageous in terms of reducing soil erosion risk and offering the potential for over-wintered stubbles for environmental stewardship. The benefit of retaining crop residue between rows has been reported in studies that suggest strip tillage systems can reduce wind velocity at the soil surface by 50% (Overstreet, 2009) and consequently can greatly reduce the risk of wind erosion.
Outcomes / Key Message For Growers And Industry
The use of strip tillage techniques in sugar beet production would potentially allow a number of benefits including reduced cultivation costs (from work rate efficiencies and a reduction in fuel used). Other benefits to the environment include increased biodiversity through the retention of over-wintered stubbles and the reduced soil erosion risk both from wind and water. A preliminary study to evaluate strip tillage mechanisms for sugar beet (including the Claydon drill and the Yetter Maverick strip tillage implement) was undertaken in autumn 2007. Initial findings from using these machines (in their current unmodified form) identified that the Yetter Maverick created more favourable seedbed conditions for sugar beet establishment, by cultivating defined strips and handling crop residue away from the row. When looking at the performance of the Yetter for sugar beet production, the system has shown significant potential on light land soil types provided that adequate consolidation can be achieved. The light land site performed well and the Yetter produced adequate plant populations of at least 80,000 plants/ha in both seasons. Implement configuration (disc selection) and / or the timing of cultivation appeared to make little difference on performance suggesting that the Yetter could be well suited to light land sugar beet production, allowing for improved timeliness of operations from fewer field passes for cultivation. As a result the performance of strip tillage (including adjusted yield and margins) indicated that the Yetter was comparable to plough tillage. On the medium soil the Yetter resulted in inadequate plant populations which were believed to be a result of poor seedbed consolidation and / or seedbed tilth in the majority of situations. Seedbed quality following autumn strip cultivations (where the soil was found to have slumped over winter) caused drilling difficulties when a standard ‘shoe-type’ opener was used that resulted in inconsistent seed depth placement. However, there was an indication that early or late spring cultivation, under suitable moisture conditions resulted in improved performance under strip tillage and was comparable to the plough. On the medium soil type disc configuration appeared to have a lesser effect on improving crop establishment and yield compared to cultivation timing, which appeared to have a significant effect. This would suggest that the Yetter implement was more sensitive to soil moisture conditions at the time of cultivation. Ploughing resulted in the highest margin figures in the majority of situations. When using the Yetter on medium soils it is considered that achieving plant populations similar to that of the plough is fundamental for comparable performance across systems; therefore further work to improve seedbed consolidation and crop establishment would be prudent in developing strip tillage for a wider range of soil types.