Agroforestry for the Management of Waterlogged Saline Soils and Poor-Quality Waters (Advances in Agroforestry Book 13)

Land degradation caused by salinity and waterlogging is a global problem afflicting about one billion hectares and endangering the food security of at least 75 countries. Since the social, economic and environmental costs of on and/off-farm reclamation techniques are high, agroforestry is now emerging as a potential tool, not only for arresting salinity and waterlogging, but also for other environmental services like mitigating climate change, sequestering carbon and restoring biodiversity. This publication addresses the vital issues, principles and practices related to rehabilitation using agroforestry and includes many site-specific case studies from a number of the world{u2019}s typical catchments. Written by leading researchers, the book is a must, not only for scientists whose research interests lie in soil salinity, waterlogging and poor-quality waters, but also policy makers, environmentalists, students, and educationists alike. More importantly, it contributes to reversing the salinity trends and ensuring the livelihoods of resource-poor farming families living in these harsh agro-ecosystems Foreword 6 Preface 8 Contents 10 Introduction 12 Global Perspectives on Agroforestry for the Management of Salt-­affected Soils 16 Introduction 16 Agroforestry for Managing Waterlogging and Salinity 18 Australian Experiences 18 Suitability of Planting Techniques 21 Agroforestry Options 21 Experiences from the Indian Subcontinent 24 Suitable Planting Techniques 24 Salt-tolerant Plants/Halophytes 25 Agroforestry Systems on Salt-­affected Lands 27 Grassland/Pastoral Systems 27 Afforestation of Coastal Saline Areas 28 Experiences from Other Areas Affected with Salinity 29 Experiences on Afforestation/Agroforestry of Alkali/Sodic Soils 30 Planting Techniques 31 Afforestation Species 31 Arable Crop-based Agroforestry Systems 33 Silvopastoral Systems 35 Fruit-based Agroforestry Systems 36 Conclusions 37 References 38 Use of Tree Plantations in Water-table Drawdown and Combating Soil Salinity 44 Introduction 45 Plantation Water Use 46 Groundwater Use and Drawdown with Trees 50 The Spatial Extents of Water Table Drawdown 51 Salt Accumulations Vis-à-Vis Plantation Sustainability 53 Considerations for Taking-up Tree Plantations 55 Conclusions 57 References 58 Prospects for Managing Salinity in Southern Australia Using Trees on Farmland 60 Causes, Extent, and Nature of Salinity in Southern Australia 61 Causes 61 Extent 61 Murray-Darling Basin (MDB) 62 Southwest Western Australia 63 Southeast South Australia and Southwest Victoria 63 Nature 64 Tree Planting Options for Managing Land and Water Salinity in Recharge and Discharge Locations 66 Managing Recharge Areas for Salinity Mitigation 66 Managing Saline Areas for Rehabilitation and Productive Use 67 Effect of Salinity on Plantation Growth and Water Use 68 Salinity and Growth 68 Salinity and Tree Water Use 73 Uptake of Shallow, Saline Groundwater by Trees 74 Irrigation with Saline Water 76 Conclusions 78 References 79 Models for Estimating Evapotranspiration of Irrigated Eucalypt Plantations 83 Introduction 84 Rationale to Develop and Use ET Models 85 Site Description 86 Plantation Establishment and Management 87 Weather During Study Period 87 Estimation and Measurements of Actual Evapotranspiration (ETa) 87 Models for Prediction of Maximum Evapotranspiration (ETm) 89 Comparison of Model Estimates and Actual Evapotranspiration 93 Comparisons Across Seasons 95 Comparisons Between Seasons 95 Comparisons during Pre- and Post-­Canopy Closure 99 Monthly Pan Factors 100 Conclusions 101 References 103 Perspectives for Bio-management of Salt-affected and Waterlogged Soils in Pakistan 106 Introduction 107 Extent of Salt-affected Waterlogged Soils in Pakistan 108 Strategies Adopted in Pakistan 110 Engineering Strategies 110 Reclamation Strategies 111 Bioremediation/Agroforestry Strategies 111 Bioremediation Species Used in Pakistan 113 Comparison of Bioremediation and Other Reclamation Strategies 114 Conclusions 114 References 115 Combating Waterlogging in IGNP Areas in Thar Desert (India): Case Studies on Biodrainage 118 Introduction 118 Indira Gandhi Nahar Project (IGNP) 119 Landforms and Physiography 119 Causes of Waterlogging in IGNP 121 Water Level Changes Due to Irrigation 121 Impact of Waterlogging 122 Biodrainage in Solving Waterlogging Problems 123 Lowering of the Raised Groundwater Table 124 Biomass Production and Carbon Sequestration 126 Salt Balance 127 Conclusions 127 References 128 Agroforestry to Rehabilitate the Indian Coastal Saline Areas 130 Introduction 130 Extent of Waterlogging and Salinity 131 Natural Vegetation and Cropping Systems 132 Afforestation/Agroforestry Systems 133 Plantations in the Areas Closer to the Sea 135 Brackish Water Aquaculture in Mangrove Areas or behind Mangroves 136 Agroforestry in Inundated Areas Due to Seawater Flooding 138 Homestead-based Integrated Farming Systems 141 Afforestation of Land Impregnated with High Salinity 143 Subsurface Freshwater Skimming System (Improved Doruvu Technology) in Coastal Areas with Sandy Soil along Sea Coast 144 Agroforestry on Waterlogged Soils Intruded with Seawater 145 Shelterbelts and Shore Protection 147 Domestication of Halophytes 147 Conclusions 148 References 149 Saline Irrigation for Productive Agroforestry Systems 153 Introduction 153 Irrigation Management Strategies 155 Tree Species for Saline Irrigation 157 Fruit and Oil-Yielding Tree Species 158 Agroforestry Systems 160 Silvopastoral Systems/Forage Grasses 161 Other Nonconventional Crops 163 Floriculture 164 Conclusions 165 References 165 Potential of Wastewater Disposal Through Tree Plantations 170 Introduction 170 Management Interventions for Risk Reduction Using Wastewater 171 Water Quality Improvements 171 Human Exposure Control 172 Phytoremediation 172 Farm-Level Wastewater Management 173 Harvest and Post-harvest Interventions 173 Urban Plantations for Wastewater Disposal 173 Selecting Appropriate Tree Plantations 174 Regulating Wastewater Use Disposal in Urban Plantations 176 Heavy Metal Recycling Potential 176 Wastewater Treatment and Nutrient Removal 178 Wastewater Treatment with Urban Plantations 179 Benefits of Wastewater Irrigation in Urban Plantations 180 Safe, Low-cost Treatment and Disposal 180 Livelihood Source 180 Environmental Benefits 181 Carbon Sequestration 181 Improvement in Climate and Energy Savings 181 Social Benefits 182 Conclusions 183 References 184 Tree Plantations in Saline Environments: Ecosystem Services, Carbon Sequestration and Climate Change Mitigation 187 Introduction 188 Agroforestry Systems for Salt-­affected Soils 188 Ecosystem Services of Biosaline Agroforestry 190 Provisioning Services 191 Soil Enrichment and Bio-amelioration 191 Amelioration of Soil Properties 191 Soil Microbial Biomass 192 Nitrogen Cycling 193 Arbuscular Mycorrhizal Fungal Diversity 193 Carbon Sequestration as an Indicator of Ecosystem Services 193 Carbon Sequestration in Plant Biomass 194 Soil Carbon Sequestration in Tree-­based Systems 194 Climate Change Mitigation and Adaptation 196 Conclusions 197 References 198 Synthesis and Way Forward: Agroforestry for Waterlogged Saline Soils and Poor-quality Waters 202 Index 207 Intro -- Foreword -- Preface -- Contents -- Introduction -- Global Perspectives on Agroforestry for the Management of Salt-affected Soils -- Introduction -- Agroforestry for Managing Waterlogging and Salinity -- Australian Experiences -- Suitability of Planting Techniques -- Agroforestry Options -- Experiences from the Indian Subcontinent -- Suitable Planting Techniques -- Salt-tolerant Plants/Halophytes -- Agroforestry Systems on Salt-affected Lands -- Grassland/Pastoral Systems -- Afforestation of Coastal Saline Areas -- Experiences from Other Areas Affected with Salinity -- Experiences on Afforestation/Agroforestry of Alkali/Sodic Soils -- Planting Techniques -- Afforestation Species -- Arable Crop-based Agroforestry Systems -- Silvopastoral Systems -- Fruit-based Agroforestry Systems -- Conclusions -- References -- Use of Tree Plantations in Water-table Drawdown and Combating Soil Salinity -- Introduction -- Plantation Water Use -- Groundwater Use and Drawdown with Trees -- The Spatial Extents of Water Table Drawdown -- Salt Accumulations Vis-à-Vis Plantation Sustainability -- Considerations for Taking-up Tree Plantations -- Conclusions -- References -- Prospects for Managing Salinity in Southern Australia Using Trees on Farmland -- Causes, Extent, and Nature of Salinity in Southern Australia -- Causes -- Extent -- Murray-Darling Basin (MDB) -- Southwest Western Australia -- Southeast South Australia and Southwest Victoria -- Nature -- Tree Planting Options for Managing Land and Water Salinity in Recharge and Discharge Locations -- Managing Recharge Areas for Salinity Mitigation -- Managing Saline Areas for Rehabilitation and Productive Use -- Effect of Salinity on Plantation Growth and Water Use -- Salinity and Growth -- Salinity and Tree Water Use -- Uptake of Shallow, Saline Groundwater by Trees -- Irrigation with Saline Water Front Matter....Pages i-x Introduction....Pages 1-4 Global Perspectives on Agroforestry for the Management of Salt-affected Soils....Pages 5-32 Use of Tree Plantations in Water-table Drawdown and Combating Soil Salinity....Pages 33-48 Prospects for Managing Salinity in Southern Australia Using Trees on Farmland....Pages 49-71 Models for Estimating Evapotranspiration of Irrigated Eucalypt Plantations....Pages 73-95 Perspectives for Bio-management of Salt-affected and Waterlogged Soils in Pakistan....Pages 97-108 Combating Waterlogging in IGNP Areas in Thar Desert (India): Case Studies on Biodrainage....Pages 109-120 Agroforestry to Rehabilitate the Indian Coastal Saline Areas....Pages 121-143 Saline Irrigation for Productive Agroforestry Systems....Pages 145-161 Potential of Wastewater Disposal Through Tree Plantations....Pages 163-179 Tree Plantations in Saline Environments: Ecosystem Services, Carbon Sequestration and Climate Change Mitigation....Pages 181-195 Synthesis and Way Forward: Agroforestry for Waterlogged Saline Soils and Poor-quality Waters....Pages 197-201 Back Matter....Pages 203-210