Poor surface drainage is costing you money field drainage is the solution
by Queensland Country Life | October 2011
The recent spate of wet growing seasons has highlighted the impact poor field drainage can have on crop production. Waterlogging due to water ponding on the ground surface is common on the flat, heavy soils commonly farmed in Queensland.
Research shows that most crops that are inundated for longer than 24 hours, typically decrease yield on average by 8% for every extra 24hrs that they are inundated. For example 7 days of continuous inundation typically reduces yield by 48%. This loss is surprisingly consistent across crop types and growth stage. In addition, poorly drained ground compacts easier, bogs machinery, delays planting and harvesting and loses fertiliser due to leaching and volatilisation. All these factors combine to greatly impact farm profit.
Historically there weren't many options available to the dryland farmer. Cutting ditches through a field often created more problems than it solved and laser grading required too much still to be shifted and was therefore too expensive for dryland cropping.
However, the latest application of precision agriculture uses GPS instead of lasers to control earthmoving machinery. This allows 3 dimensional design surfaces to be used which follow the natural topography more closely and therefore greatly reduce the necessary earthworks, while still removing any depressions in the field that pond water. This makes landforming cost effective for many farmers who previously dismissed the concept.
A Queensland farming organisation, DAVCO Farming has been at the forefront of this new wave. As David Cox, principal of DAVCO Farming explains, "We farm and fully understand the benefits of precision surface drainage of agricultural fields. We were one of the first growers in the world to use laser levelling in sugarcane production starting back in the 1970s. It was a tremendous leap in technology enabling the transformation of basic land into highly efficient and very productive farming operations.
However, the problem with laser levelling and its corresponding multiple plane designs is that we often see more than 4 times the earthworks compared to the new technology. Apart from the much larger earthmoving cost that this involves, it also scalps a lot more topsoil which can have significant impacts on crop yields for decades. We continue to develop land for sugarcane farming and saw the opportunity that GPS machine control offered in solving the limitations of laser levelling. So over ten years ago, we set about coming up with a system that took full advantage of this new technology. That is what we call Optimum Surface Landforming or OptiSurface for short."
OptiSurface Designer is the software package which automatically calculates the optimum 3D field topography that satisfies drainage goals whilst minimising earthworks. Used in conjunction with Trimble's Field Level Il GPS Levelling system. Optisurface Designer delivers a total cost effective solution for poor surface drainage.