CONSERVATION CROP FARMING – A FARM MANAGEMENT PERSPECTIVE PAGE 1 CONSERVATION CROP FARMING: A FARM MANAGEMENT PERSPECTIVE Paul Lewis, Bill Malcolm and Graham Steed A FACULTY OF LAND AND FOOD RESOURCES, UNIVERSITY OF MELBOURNE, PARKVILLE, VICTORIA. 3052 CONSERVATION CROP FARMING – A FARM MANAGEMENT PERSPECTIVE PAGE 2 Table of Contents 1. –INTRODUCTION....................................................................................................................11 1.1. INTRODUCTION TO THE PROJECT ...........................................................................................11 2. –A TECHNICAL LITERATURE REVIEW ............................................................................11 2.1. INTRODUCTION ....................................................................................................................11 2.2. OVERVIEW - A BRIEF HISTORY OF CONSERVATION TILLAGE ...................................................12 2.2.1. Cropping in South-Eastern Australia ...............................................................................15 2.2.2. Residue retention.............................................................................................................16 2.2.3. Machinery.......................................................................................................................17 2.3. PROCESSES UNDERLYING PLANT AND SOIL RESPONSES ...........................................................18 2.3.1. Yield impacts of different tillage and stubble treatments...................................................18 2.4. EFFECTS OF CONSERVATION CROPPING ON SOIL PHYSICAL PROPERTIES....................................21 2.4.1. impact of tillage and stubble management on soil structure..............................................21 2.4.2. Structural stability...........................................................................................................25 2.4.3. Soil erosion .....................................................................................................................26 2.4.4. Soil strength and compaction...........................................................................................26 2.4.5. Stubble management........................................................................................................28 2.4.6. Fallowing........................................................................................................................32 2.4.7. Controlled traffic.............................................................................................................34 2.5. CONSERVATION CROPPING AND THE CHEMICAL PROPERTIES...................................................37 2.5.1. Soil organic matter and organic carbon...........................................................................37 2.5.2. Stubble burning...............................................................................................................39 2.5.3. Microbial activity............................................................................................................40 2.5.4. Nitrogen..........................................................................................................................41 2.5.5. Soil pH............................................................................................................................41 2.6. CONSERVATION CROPPING AND ITS BIOLOGICAL IMPACTS ......................................................42 2.7. SOIL/WATER INTERACTIONS..................................................................................................45 2.7.1. The use of gypsum and lime in combination with conservation cropping...........................46 2.8. THE IMPACT OF CONSERVATION CROPPING ON GROWTH, WEEDS, DISEASE AND PESTS..............47 2.8.1. Time of sowing ................................................................................................................47 2.8.2. Establishment..................................................................................................................50 2.8.3. Weed management and herbicide resistance ....................................................................51 2.8.4. Nutrition .........................................................................................................................54 2.8.5. Disease ...........................................................................................................................56 Root and crown diseases..........................................................................................................................56 Leaf and stem diseases ............................................................................................................................58 2.8.6. Pests ...............................................................................................................................60 2.9. CROPPING SYSTEMS AND ROTATION......................................................................................60 2.10. A REGIONAL PERSPECTIVE ON CONSERVATION CROPPING SYSTEMS. ........................................61 2.10.1. Southern New South Wales and North East Victoria.....................................................61 2.10.2. The Wimmera..............................................................................................................64 2.10.3. The Mallee..................................................................................................................65 2.10.4. North Central Victoria ................................................................................................66 2.10.5. Western Australia........................................................................................................66 2.10.6. Other areas.................................................................................................................67 3. ADOPTION OF CONSERVATION CROPPING ....................................................................67 3.1. ADOPTION SURVEYS IN SOUTH EASTERN AUSTRALIA .............................................................67 3.2. THE SURVEYS ......................................................................................................................67 3.2.1. Eyre Peninsula................................................................................................................67 Stubble management ...............................................................................................................................68 Cultivation..............................................................................................................................................68 Herbicide usage.......................................................................................................................................68 Nutrition .................................................................................................................................................69 3.2.2. Mallee.............................................................................................................................69 Rotation..................................................................................................................................................69 3.2.3. Other Areas.....................................................................................................................71 CONSERVATION CROP FARMING – A FARM MANAGEMENT PERSPECTIVE PAGE 3 3.3. SUMMARY OF A FARMER SURVEY OF AUSTRALIAN MINIMUM TILLAGE FARMING METHODS.....73 3.3.1. Background.....................................................................................................................73 3.3.2. Adoption of no-till and cropping Area..............................................................................73 3.3.3. Tillage methods and sowing machinery............................................................................74 3.3.4. Weed control...................................................................................................................79 3.3.5. Stubble management........................................................................................................79 3.3.6. Comparing conventional and no-till systems ....................................................................81 3.3.7. Barriers to adoption ........................................................................................................84 3.3.8. Reasons for adoption.......................................................................................................87 3.3.9. Summary.........................................................................................................................90 3.4. ADVISOR SURVEY OF CONSERVATION CROPPING..............................................................90 3.4.1. Aim .................................................................................................................................90 3.4.2. Methods ..........................................................................................................................90 3.4.3. Results - How will the area of crop in your area change over the next 5 and 15 years......91 3.4.4. What is the current trend for area of direct drilling (DD) in your region and what do you predict for this trend over the next 15 years..................................................................................91 3.4.5. Explanation of trends for direct drill/