| Semester 1, 2022 Toowoomba On-campus | |
| Units : | 1 |
| Faculty or Section : | Faculty of Health, Engineering and Sciences |
| School or Department : | School of Agriculture and Environmental Science |
| Grading basis : | Graded |
| Course fee schedule : | /current-students/administration/fees/fee-schedules |
Staffing
Examiner:
Overview
Agriculture machinery interacts with soils in a number of ways, and so the processes of tillage, traction and compaction are of vital interest to engineers involved in agriculture. This course investigates these processes by developing a detailed understanding of the response of soils to imposed stresses and their resulting deformations and modes of failure. A theoretical framework that explains and describes the action of tillage tools, the development of wheel tractive forces, and the process of soil compaction is established. Methods for accessing and describing soil structure, and efficient operation of soil engaging tools are discussed and linked to plant growth and crop yield. The process of soil compaction and the practice of controlled traffic will also be reviewed. The course uses real world data sets from both field and lab work to show how the theory is related to practice.
Course learning outcomes
The course objectives define the student learning outcomes for a course. On completion of this course, students should be able to:
- assess soil structure, understand its importance for plant growth;
- describe and calculate mechanical and strength properties of soil elements;
- evaluate the tillage process and calculate tillage forces;
- methods to measure soil forces and compare the influence of different tillage tool designs;
- describe and interpret the process of soil compaction, calculate its effect on soil properties, and discuss its effects on plant growth;
- calculate wheel tractive forces, rolling resistance and tractive efficiency of tractor/implement systems;
- describe and discuss the theory and applications of controlled traffic farming systems;
- describe and discuss the concept of critical state soil mechanics
Topics
| Description | Weighting(%) | |
|---|---|---|
| 1. | Soil structures. Soil physical properties. | 10.00 |
| 2. | Stress theory. Soil failure and mechanical behaviour. Soil strength measurement methods. | 15.00 |
| 3. | The tillage process and soil failure modes. Calculation of tillage forces. Analysis and design of tillage tools and implements. | 20.00 |
| 4. | Implications of soil compaction on machinery design and for root and plant growth. | 10.00 |
| 5. | Development of traction by wheels and tracks. Calculation of soil rolling resistance and wheelslip. Optimum matching between the tractor and the implement. | 20.00 |
| 6. | Critical state soil mechanics | 10.00 |
| 7. | Soil compaction and controlled traffic farming method | 15.00 |
Text and materials required to be purchased or accessed
Student workload expectations
To do well in this subject, students are expected to commit approximately 10 hours per week including class contact hours, independent study, and all assessment tasks. If you are undertaking additional activities, which may include placements and residential schools, the weekly workload hours may vary.
Assessment details
| Description | Group Assessment |
Weighting (%) | Course learning outcomes |
|---|---|---|---|
| Problem Solving 1 | No | 20 | 1,2,3 |
| Essay | No | 15 | 3,4,5 |
| Problem Solving 2 | No | 15 | 5,6 |
| Time limited online examinatn | No | 50 | 1,2,3,4,5,6 |