SOIL HEALTH GUIDE WHEATBELT NRM’S VISION ‘To Bring Exemplary Natural Resource Management to the Wheatbelt to Create Healthy Environments and Livelihoods.’
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WHEATBELT NRM SOIL HEALTH GUIDE WHEATBELT NRM’S VISION ‘To bring exemplary natural resource management to the Wheatbelt to create healthy environments and livelihoods.’ WHEATBELT NRM SOIL HEALTH GUIDE November 2013 ISBN: 978-0-9924243-0-5 Wheatbelt NRM Soil Health Guide This document should be cited as: Wheatbelt NRM (2013) Wheatbelt NRM Soil Health Guide, Wheatbelt Natural Resource Management, Northam, Western Australia ACKNOWLEDGEMENTS Wheatbelt NRM would like to acknowledge We would like to recognise the contribution of the following the generous contribution of the following organisations directly to these case studies or indirectly through the people: support of the Soil Conservation Incentive Program (SCIP): Editors: Dr David Grasby Delivery organisations including: Dr Guy Boggs • AVONGRO Georgie Troup • Department of Agriculture and Food Western Australia (DAFWA) Wheatbelt NRM Project Team: • Oil Mallee Association (OMA) Sally Sprigg, Jo Wheeler and Chris David for • Western Australian No-Tillage Farmers Association (WANTFA) their contributions to the implementation Project support organisations including: of the Soil Conservation Incentive Program and case study material. Local Government Authorities • Shire of Kellerberrin • Shire of Trayning Thanks also to previous Wheatbelt NRM • Shire of Quairading • Shire of Mt Marshall staff members, Daniel Ferguson and • Shire of Westonia • Shire of Yilgarn Rochelle Horlin. • Shire of Bruce Rock The contribution of David Bicknell, DAFWA, to the issues and soil health issues section of Individual Project Support Offi cers: the guide is gratefully acknowledged. • Jade Dempster • Samantha Pickering • Linda Vernon • Tracey Hobbs Maps created by Kathryn Horrocks, GIS Project Offi cer, Wheatbelt NRM. • Kezia Metcalf Graphic design by Stylus Design. This project is supported by Wheatbelt NRM, through funding from the Australian Government. Adoption of innovations survey analysis by Dr Dimity Boggs. DISCLAIMER The views and opinions expressed in this publication do not necessarily refl ect those of the Australian Government or Wheatbelt NRM. FOREWORD Is reliable, sustainable, management of Western Australia’s Wheatbelt Agricultural soils of the utmost importance? As the leading Natural Resource Management group, actively engaged in addressing a wide and diverse range of natural resource issues in the Wheatbelt, we think so. Wheatbelt Natural Resource Management, (Wheatbelt NRM) is keen to see those involved in Agriculture adopt strategies to improve the health of the soils. The ‘Soil Health Guide’, produced by Wheatbelt NRM, draws from the experience of farmers from across the region who are seeking to farm more sustainably. The Soil Health Guide has been designed to demonstrate the feasibility of adopting agriculturally sustainable practices, by way of both case studies and the practical energies that will assist land management practitioners to explore farming practices to help them best manage this valuable natural resource. Soil, its management and protection, is fundamental to the sustainability of agriculture in Western Australia. Wheatbelt NRM has a very well developed Sustainable Agricultural program that assists farmers and all those involved in land management to maintain a productive and environmentally sustainable agricultural industry. The program works with Farmers, Grower Groups, Researchers and Industry Experts, to support the development and adoption of farming practices that will improve the condition of all soils and drive the sustainability and long term fi nancial assurances of ‘whole farming’ enterprises. The Wheatbelt has a number of challenges that relate to soils, and infl uences how they are managed. Projects run through the Sustainable Agricultural Program, such as the Soil Conservation Incentive Program, are working with over 200 Farmers to trial and demonstrate innovative cropping, grazing soil manipulation and agroforestry practices that address issues ranging from soil acidity and salinity to non-wetting characteristics, depleted organic matter and erosion. The case studies that form part of this guide have all been drawn from Wheatbelt NRM’s Sustainable Agricultural Program and are designed to show, in a practical way, how farmers and those involved can adopt the practices to their own properties. Thank you, Jim Sullivan Chairperson, Wheatbelt NRM WHEATBELT NRM SOIL HEALTH GUIDE WHEATBELT NRM SOIL HEALTH GUIDE CONTENTS INTRODUCTION . 1 HOW TO USE THIS GUIDE . 2 WHAT IS SOIL HEALTH? . 4 PRINCIPLES OF SUSTAINABLE LAND MANAGEMENT . 5 SOIL HEALTH ISSUES IN THE WHEATBELT . 7 Soil acidity . 8 Wind erosion . 8 Soil organic carbon . 9 Soil biology . 9 Soil structure decline . 10 Water repellence . 11 Dryland salinity . 11 Nutrient status and nutrient export . 13 WHEATBELT SUSTAINABLE FARMING PRACTICES . 14 Agroforestry . 15 Innovative cropping solutions . 17 Sustainable grazing . 18 Innovative soil management . 19 Adoption of sustainable farming practices . 20 CASE STUDIES AND FACT SHEETS FOR SUSTAINABLE LAND MANAGEMENT. 22 AGROFORESTRY . 24 Using trees to protect crops . 24 Farming with windrows . 26 Mt Marshall Sandalwood . 28 A decade of growing, observing and learning about sandalwood . 31 The story of Jogalong Downs: multiple benefits from a long term experience with tree planting . 35 Casuarina obesa in the Avon Wheatbelt: Management of native stands and provenance trials . 38 GRAZING PRACTICES: PASTURES . 42 Bulking up Serradella for on-farm use . 42 Attempting to improve land use at sandy and salty sites . 44 Introducing native perennial grasses into a farming system . 46 Improved pastures for slightly saline paddocks . 48 Perennial pastures turn unproductive sand into productive land . 50 Pasture cropping: an option for marginal land . 52 Summer grazing options . 54 Best inoculation techniques for pasture legumes . 56 WHEATBELT NRM SOIL HEALTH GUIDE GRAZING PRACTICES: FORAGE SHRUBS . 58 Saltbush instead of samphire in the salt flats . 58 Rehabilitating salt land for greater purpose . 60 Cross-boundary Tagasaste plantings provide a win–win solution to wind erosion . 62 Planting tagasaste to improve and protect ‘gutless’ sands . 65 Alternative fodder shrub for low rainfall areas: Rhagodia . 66 Wasteland no more. 67 CROPPING PRACTICES . 69 Making the right decisions at seeding . 69 The importance of crop rotations . 72 Stubble retention . 74 Cover crop options and knife rolling . 76 Trialling best cropping practices for maximum soil cover . 78 SOIL IMPROVEMENT . 81 Travelling a different path for soil health . 81 Working out the cost effectiveness of liming . 84 Soil pH revisited . 86 Managing water repellent soils . 88 Overcoming non-wetting soils: Clay incorporation 2010–2013 . 91 Soil testing for levels of carbon and nitrogen under three land-use regimes . 94 Soil carbon change in farming systems of the Avon River Basin . 97 Sifting through the ‘grey areas’: learning more about alternative fertiliser options . 99 REFERENCES . 102 WHEATBELT NRM SOIL HEALTH GUIDE INTRODUCTION Agriculture has a long and successful history in the Wheatbelt of Western Australia, beginning with the settlement of York in 1831. Today, agricultural production contributes 50% ($3.1b per annum) of the Avon region’s GDP and covers almost 6.6 million ha. However, the development of land for agriculture has had some negative effects on.