Conference proceeding
Optimizing bentleg opener geometry for high speed no-till seeding using DEM simulations
Proceedings of the 21st ISTRO International Conference, pp.410-412
21st ISTRO Conference (Paris, France., 24/09/2018 - 27/09/2018)
2018
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Abstract
Introduction
Tine-mounted narrow openers commonly used in Australia for no-tillage seeding operations cause excessive soil disturbance, which typically limits speed to 8-9 km h-1. In this study, the low disturbance bentleg opener (Barr, Desbiolles, & Fielke, 2016; Solhjou, Fielke, Desbiolles, & Saunders, 2014) is investigated for its use in high speed no-tillage seeding. Discrete element method (DEM) modelling was used to optimise performance and develop bentleg opener designs for integrated use in seeding systems.
Method
A virtual soil bin was generated using DEM and the hysteretic spring contact model (Ucgul, Fielke, & Saunders, 2014). A voidage grid binning technique was developed to identify the loosened soil portion following a furrow tilling simulation and adapting DEM post processing to reflect common tillage assessment methodologies. The performance of bentleg openers and seeding systems was benchmarked against baseline straight openers in field trials on siltyloam and sandy-loam soils, by measuring parameters such as soil disturbance, tillage forces, seed placement accuracy, crop emergence and grain yield.
Results and Discussion
DEM model results show soil disturbance with bentleg openers is minimised by streamlining the opener by reducing its thickness and maximising its leading chamfer. A curved rather than angular- transition connecting the side leg to the vertical shank portion also reduces the extent of soil disturbance. The bentleg foot is the key feature initiating soil failure and driving soil loosening, draught and penetration forces. However, the vertical upheave caused by the foot increases soil throw at shallower settings (< 90 mm). Removing the foot reduces the loosened soil upheave height, minimising soil disturbance for shallow (60 mm) and high speed operation. These benefits come at the cost of furrow loosening capacity, limiting the operating range of footless bentleg openers to shallower depths (< 120 mm). However, a footless bentleg opener with a side-leg forward rake angle greater than 90° can offer benefits similar to steep rake angle straight openers, but without the associated penalties of reduced furrow size, increased draught and vertical up forces. Benefits include the potential to lower field surface roughness, improve harvest-ability of crops and reduce the need for post seeding rolling operations in stony soils. In both DEM predicted and field experimental results in dry conditions (Fig. 1) the bentleg opener was able to operate with less soil throw at twice the operating speed (16 km h-1) relative to the straight opener (8 km h-1).
Details
- Title
- Optimizing bentleg opener geometry for high speed no-till seeding using DEM simulations
- Creators
- James Barr - University of South AustraliaJack Desbiolles - University of South AustraliaJohn Fielke - University of South AustraliaMustafa Ucgul - University of South Australia
- Publication Details
- Proceedings of the 21st ISTRO International Conference, pp.410-412
- Conference
- 21st ISTRO Conference (Paris, France., 24/09/2018 - 27/09/2018)
- Publisher
- International Soil Tillage Research Organization
- Identifiers
- 991013044013402368
- Academic Unit
- Faculty of Science and Engineering
- Language
- English
- Resource Type
- Conference proceeding