Information
Level 2 Detail of experimental conditions (what might be found in a journal paper or project brief in Hydstra)
Description of study
What?
The effect of tractor traffic on runoff and infiltration under common tillage systems, stubble mulch, minimum till and zero till were studied on a self-mulching alluvial black earth.
Li et al, 2008 (a) evaluated the PERFECT model using data collected from 1995-99 on a controlled traffic experiment at Gatton.
Li et al, 2008 (b), used a modelling approach to estimate the long-term effect of tillage, traffic, crop rotation and type and soil management practices in a heavy clay soil.
When and Where?
The study was conducted on a self-mulching alluvial black earth at Gatton adjacent to Lockyer Creek, Queensland. The soil exhibits moderate cracking and contains highly permeable gravel/sand mixture. Soil texture changes slightly within the plots as does slope.
Average annual rainfall was 785mm with 70% of the total falling in the period October-March.
The cropping system undertaken was similar to that of dryland farmers however supplementary irrigation was provided on several occasions to ensure crop survival.
How?
Tullberg et al, 2001 implemented a 3-m controlled traffic system, providing a 2.5-m cropped ‘bed’ width and 0.5-m permanent traffic ‘lane’. The front and rear axles of a 70-kW 2-wheel-drive tractor (John Deere 4040) were modified to provide 3-m track width, and the tractor was fitted with rear tyres of 0.43 m section width (16.9 by 38 in.), with furrowers on a subframe ahead of the tractor rear wheels.
A ‘split-plot’ experimental design was used with 2 experimental plots, wheeled and controlled traffic (non-wheeled), making up each tillage treatment. A complete experimental block, comprising the 3 tillage treatments (stubble mulch, minimum, and zero) with one guard plot at each side, was thus 24 m wide (Figure 1).
Tillage treatments were randomised within blocks, but a consistent wheeled/controlled traffic plot pattern was maintained within each block to avoid errors due to different traffic lane/furrow cracking characteristics.
Traffic lanes for all plots passed over a cutoff trench at the top of the slope and diversion bank at the bottom of the slope to define the collection area. The complete experiment involved 24 plots (2 wheeling treatments × 3 tillage treatments × 4 replicates), each having a tipping bucket unit of 6 L capacity, and monitored by data logger units mounted in the tipping bucket pits.
Li et al, 2001 assessed the impact of compaction from wheel traffic on soil that had not been trafficked for 5 years. A tractor of 40 kN rear axle weight was used to apply traffic at varying wheelslip on a clay soil with varying residue cover to simulate effects of traffic typical of grain production operations in the northern Australian grain belt. A rainfall simulator was used to determine infiltration characteristics.
Li et al, 2008a set up a split-plot experimental design similar to that of Tullberg et al, 2001, however the study was conducted from 1995-99. The data obtained was then used to evaluate the PERFECT model.
Li et al, 2008b used the same data obtained from 1995-99 in order to simulate the PERFECT model over a 44 year period using archived weather data. The effects of traffic and tillage on water balance, soil loss and crop yield for continuous wheat, continuous sorghum and wheat-sorghum opportunity systems were explored.
Project administration
Site identifier code: na
Principal investigator: Tullberg JN and Li YX
Principal data manager: -na
Principal organizations: Australian Centre for International Agricultural Research
Data custodian: School of Agriculture and Horticulture, The University of Queensland, Gatton
Key co-operators: na
Data access policy: Research has been published but base data is not archived
Planned pathway for data: completed study, no evidence of formal database records.
Data warehousing: for ongoing studies -na
Planned data upload frequency: for ongoing studies -na
Key references and sources of this data synthesis
These data summaries have been extracted from:
- i. Li X, Tullberg JN, Freebairn DM. 2001. Traffic and residue cover effects on infiltration. Australian Journal of Soil Research 39: 239-247.
- ii. Li XY, Tullberg JN, Freebairn DM, McLaughlin NB, Li HW. 2008. Effects of tillage and traffic on crop production in dryland farming systems: I. Evaluation of PERFECT soil-crop simulation model. Soil and Tillage Research 100:15-24.
- iii. Li XY, Tullberg JN, Freebairn DM, McLaughlin NB, Li HW. 2008. Effects of tillage and traffic on crop production in dryland farming systems: II. Long-term simulation of crop production using the PERFECT model. Soil and Tillage Research 100: 25-33.
- iv. Tullberg JN, Ziebarth PJ, and Li Y. 2001. Tillage and traffic effects on runoff. Australian Journal of Soil Research 39: 249-257.
Keywords:
Controlled traffic, conservation tillage, rainfall/runoff hydrograph, wheeling, clay soil, simulation modelling, curve number, stubble mulch, PERFECT model