Contributors  XV

Foreword  XXII

Acknowledgements  XXIV

Abbreviations  XXV

Chapter 1 | Introduction  1

1.1 Purpose and approach of the report  1

1.2 Structure of the report  3

References for Chapter 1  4

Chapter 2 | Soils and the Sustainable Development Goals  7

2.1 Introduction  7

2.2 Ecosystem services, nature's contributions to people, and soil functions  8

2.3 Links between soils and specific Sustainable Development Goals  11

2.3.1 Food security and sustainable agriculture (SDG 2: Zero Hunger)  11

2.3.2 Water security and resources (SDG 6: Clean Water and Sanitation)  15

2.3.3 Anthropogenic climate change (SDG 13: Climate Action)  16

2.3.4 Soil pollution and human and ecosystem health  21

2.3.5 Soil biodiversity (SDG 15: Life on Land)  24

2.3.6 Terrestrial ecosystems (SDG 15: Life on Land)  26

2.3.7 SDG 11: Sustainable Cities and Communities  28

2.4 Soils and human societies  29

2.5 Summary  30

References for Chapter 2  31

Chapter 3 | Threats to soil functions  37

3.1 Introduction and scope of chapter  37

3.2 Soil erosion  38

3.2.1 Introduction  38

3.2.2 Thresholds for erosion  38

3.2.3 Water erosion  39

3.2.4 Wind erosion  44

3.2.5 Tillage erosion  47

3.2.6 Shallow landslides  48

3.2.7 Soil loss due to crop harvesting  49

3.3 Soil organic carbon loss  50

3.3.1 Introduction  50

3.3.2 Soil organic carbon loss in mineral soils: Definition and processes responsible for loss  52

3.3.3 Soil organic carbon from wetlands, peatlands and mangrove forests  61

3.3.4 Soil organic carbon loss in permafrost soils  65

3.3.5 Soil inorganic carbon loss  69

3.4 Soil biodiversity change  70

3.4.1 Introduction  70

3.4.2 Global assessments of soil biodiversity  70

3.4.3 Global threats to soil biodiversity  71

3.5 Nutrient mismanagement  76

3.5.1 Overview of nutrient balances  76

3.5.2 Environmental consequences of nutrient excess  79

3.5.3 Nutrient mining and yield gaps  83

3.5.4 Acidification  84

3.6 Salt accumulation  87

3.6.1 Overview of salt accumulation  87

3.6.2 Global distribution of salt-affected soils  88

3.6.3 Drivers of changes in salt accumulation  92

3.7 Soil pollution  94

3.7.1 Introduction  94

3.7.2 Inorganic pollutants  98

3.7.3 Organic pollutants  99

3.7.4 Emerging pollutants  101

3.8 Urban expansion and changes to soil functions  102

3.8.1 Introduction  102

3.8.2 Effects of urbanization on soil functions and ecosystem services  103

3.9 Physical degradation  105

3.9.1 Introduction  105

3.9.2 Soil compaction, hardsetting and workability  105

3.10 Summary  108

3.10.1 Introduction  108

3.10.2 Summary for soil erosion  108

3.10.3 Summary for soil organic carbon loss  109

3.10.4 Soil biodiversity  110

3.10.5 Nutrient mismanagement  110

3.10.6 Salt accumulation  112

3.10.7 Soil pollution  113

3.10.8 Urban expansion and soil sealing  113

3.10.9 Soil compaction  114

References for Chapter 3  115

References for Box 3.1  128

References for Box 3.2  129

Chapter 4 | Direct and indirect drivers of threats to soil functions  131

4.1 Overview of drivers  131

4.2 Indirect drivers  134

4.2.1 Population change  134

4.2.2 Demand for food and wood  136

4.3 Direct drivers  138

4.3.1 Land-use change  138

4.3.2 Changes in agrochemical use  143

4.3.3 Changes in agricultural and forestland management  149

4.3.4 Urban expansion, infrastructure development and extractive industries  152

4.4 Conflict as a driver of soil change  158

4.5 Summary  163

References for Chapter 4  166

Chapter 5 | Sustainable soil management in support of the Sustainable Development Goals  171

5.1 Introduction  171

5.2 Cross-cutting sustainable soil management practices  172

5.2.1 Manure additions  172

5.2.2 Cover crops  173

5.2.3 Residue retention, residue return and mulching  174

5.2.4 Biochar  175

5.2.5 No-till and reduced tillage  176

5.2.6 Improved nutrient management  178

5.2.7 Organic agriculture  183

5.2.8 Agroforestry  184

5.2.9 Regenerative agriculture  184

5.2.10 Conservation agriculture  186

5.3 Sustainable soil management to improve food security and support sustainable food systems (SDG 2 and SDG 11)  187

5.3.1 Introduction  187

5.3.2 Reducing soil erosion caused by water, tillage and crop harvest  187

5.3.3 Reducing nutrient mining  192

5.3.4 Reducing acidification  194

5.3.5 Reducing salt accumulation  195

5.3.6 Reducing loss of agricultural land to urban expansion  197

5.4 Water security and water resources (SDG 6)  199

5.4.1 Introduction  199

5.4.2 Reducing runoff and sedimentation  199

5.4.3 Increasing water-use efficiency in agriculture  201

5.4.4 Reducing agrochemical pollution of water  204

5.5 Human-induced climate change (SDG 13: Climate Action)  205

5.5.1 Introduction  205

5.5.2 Estimates of mitigation potential of soil-based practices  205

5.5.3 Increasing soil organic carbon content  207

5.5.4 Reducing nitrous oxide and methane emissions from soil  210

5.5.5 Reducing carbon dioxide emissions from soil inorganic sources  212

5.6 Soil pollution and human and ecosystem health (SDG 3: Good Health and Well-being)  213

5.6.1 Introduction  213

5.6.2 Reducing soil pollution and remediating polluted sites  213

5.6.3 Reducing ammonia emissions from soils  218

5.7 Halt the loss of soil biodiversity and reduce wind erosion (SDG 15: Life on Land)  219

5.7.1 Introduction  219

5.7.2 Halt the loss of soil biodiversity  219

5.7.3 Reducing loss of wetlands and organic soils  221

5.7.4 Reducing wind erosion  222

5.7.5 Reducing shallow landslides  223

5.8 Summary  225

Conclusion  230

References for Chapter 5  231

Sources for Table 5.6  242

Chapter 6 | Facilitating the adoption of sustainable soil management  245

6.1 Introduction  245

6.2 Traditional and Indigenous Peoples' knowledge  246

6.3 Soil information  248

6.4. Education and public awareness  251

6.5. Economic benefits  253

6.6. Incentives for adoption  255

6.7 Soil governance at a global scale  257

6.8. Conclusions  259

References for Chapter 6  260

Chapter 7 | Criteria for assessment of state, trend and confidence for the regional assessments  265

7.1 Introduction  265

7.2 Development of the criteria for assessment of state and trend  265

7.3 Specific classes used for state and trend  266

7.4 Methodology for regional assessments, graphical summaries and confidence rating  269

7.5 Differences between the 2015 and 2026 Status of the world's soil resources reports  271

References for Chapter 7  273

Chapter 8 | Regional assessment for Asia  275

8.1 Regional overview  276

8.1.1 Characteristics of region and subregions  276

8.2 Changes in drivers of threats to soil functions  282

8.2.1 Population growth  282

8.2.2 Land-use change  282

8.2.3 Nutrient management  287

8.2.4 Climate change  289

8.3. Regional status and trends of threats to soil functions for the East Asia subregion  290

8.3.1 Introduction  290

8.3.2 Soil erosion in the East Asia subregion  290

8.3.3 Loss of soil organic carbon in East Asia subregion  292

8.3.4 Loss of soil biodiversity in East Asia subregion  294

8.3.5 Nutrient mismanagement in East Asia subregion  295

8.3.6 Salt accumulation in East Asia subregion  297

8.3.7 Soil pollution in East Asia subregion  298

8.3.8 Urban expansion and soil sealing in East Asia subregion  299

8.3.9 Other threats in East Asia subregion  302

8.4 Regional status and trends of threats to soil functions for the South Asia subregion  304

8.4.1 Introduction  304

8.4.2 Soil erosion in South Asia subregion  304

8.4.3 Loss of soil organic carbon in South Asia subregion  305

8.4.4 Loss of soil biodiversity in South Asia subregion  306

8.4.5 Nutrient mismanagement in South Asia subregion  306

8.4.6 Salt accumulation in South Asia subregion  307

8.4.7 Soil pollution in South Asia subregion  308

8.5 Regional status and trends of threats to soil functions for the Southeast Asia subregion  310

8.5.1 Introduction  310

8.5.2 Soil erosion in Southeast Asia subregion  314

8.5.3 Loss of soil organic carbon in Southeast Asia subregion  324

8.5.4 Nutrient mismanagement in Southeast Asia subregion  327

8.5.5 Salt accumulation in Southeast Asia subregion  330

8.5.6 Soil acidification in Southeast Asia subregion  332

8.5.7 Urban expansion and soil sealing in Southeast Asia subregion  336

8.5.8 Soil pollution in Southeast Asia subregion  336

8.5.9 Soil water availability  338

8.5.10 Other issues  338

8.6 Trends in sustainable soil management  341

8.6.1 Summary of state and trend in sustainable soil management  341

8.6.2 Progress in and impediments to adoption of sustainable soil management  344

8.6.3 Recommendations for future priorities for action  344

References for Chapter 8  345

Sources for Table 8.19  361

Chapter 9 | Regional assessment for Europe and Central Asia  365

9.1 Regional overview  366

9.1.1 Characteristics of the region  366

9.1.2 Summary of status from the 2015 Status of the world's soil resources report  368

9.2 Changes in the drivers of threats to soil functions  369

9.2.1 Overall population and urban population growth  369

9.2.2 Land-use changes  369

9.2.3 Nutrient management  372

9.3 Regional status and trend of threats to soil functions for Europe and Central Asia  374

9.3.1 Introduction  374

9.3.2 Soil erosion in Europe and Central Asia  378

9.3.3 Loss of soil organic carbon in Europe and Central Asia  382

9.3.4 Loss of soil biodiversity in Europe and Central Asia  388

9.3.5 Nutrient mismanagement in Europe and Central Asia  389

9.3.6 Soil acidification in Europe and Central Asia  393

9.3.7 Soil pollution in Europe and Central Asia  395

9.3.8 Salt accumulation in Europe and Central Asia  400

9.3.9 Soil compaction in Europe and Central Asia  401

9.3.10 Urbanization and soil sealing in Europe and Central Asia  403

9.4 Trends in sustainable soil management in Europe and Central Asia  405

9.4.1 Examples of promising trends in sustainable soil management  405

9.4.2 Impediments to adoption of sustainable soil management  408

9.4.3 Conclusion and recommendations  409

References for Chapter 9  411

References for Table 9.2  421

References for Table 9.4  423

References for Table 9.10  425

Chapter 10 | Regional assessment for Latin America and the Caribbean  429

10.1 Latin America and the Caribbean regional overview  430

10.1.1 Characteristics of region and subregions  430

10.1.2 Status summary from the 2015 Status of the world's soil resources report  436

10.2. Changes in the direct and indirect drivers of threats to soil functions  437

10.2.1 Population growth  437

10.2.2 Land-use change  437

10.2.3 Nutrient management  441

10.3 Regional status and trend of threats to soil functions for Central America, southern Mexico and the Caribbean subregion  446

10.3.1 Soil erosion in the Central America, southern Mexico and the Caribbean subregion  446

10.3.2 Soil carbon loss in the Central America, southern Mexico and the Caribbean subregion  447

10.3.3 Soil biodiversity loss in the Central America, southern Mexico and the Caribbean subregion  448

10.3.4 Nutrient mismanagement in the Central America, southern Mexico and the Caribbean subregion  448

10.3.5 Salt accumulation in the Central America, southern Mexico and the Caribbean subregion  449

10.3.6 Soil moisture change in the Central America, southern Mexico and the Caribbean subregion  450

10.4 Regional status and trend of threats to soil functions for the Amazon subregion  451

10.4.1 Introduction  451

10.4.2 Soil erosion in the Amazon subregion  453

10.4.3 Soil carbon loss in the Amazon subregion  455

10.4.4 Soil biodiversity change  456

10.4.5 Nutrient mismanagement in the Amazon subregion  457

10.4.6 Soil pollution in the Amazon subregion  458

10.4.7 Urbanization and soil sealing in the Amazon subregion  458

10.5 Regional status and trend of threats to soil functions for the Cerrado subregion  459

10.5.1 Soil erosion in the Cerrado subregion  459

10.5.2 Loss of soil organic carbon in the Cerrado subregion  462

10.5.3 Soil biodiversity loss in the Cerrado subregion  465

10.5.4 Nutrient mismanagement in the Cerrado subregion  466

10.5.5 Salt accumulation in the Cerrado subregion  467

10.5.6 Soil pollution in the Cerrado subregion  467

10.5.7 Other threats in the Cerrado subregion  468

10.6 Regional status and trend of threats to soil functions for the Del Plata Basin subregion  469

10.6.1 Soil erosion in the Del Plata subregion  469

10.6.2 Loss of soil carbon in the Del Plata subregion  470

10.6.3 Soil biodiversity loss in the Del Plata subregion  471

10.6.4 Nutrient mismanagement in the Del Plata subregion  472

10.6.5 Salt accumulation in the Del Plata subregion  472

10.6.6 Soil pollution in the Del Plata subregion  473

10.6.7 Urbanization and soil sealing in the Del Plata subregion  473

10.7 Regional status and trend of threats to soil functions for the Andean countries and Patagonia subregion  474

10.7.1 Soil erosion in the Andean countries and Patagonia subregion  474

10.7.2 Soil carbon loss in the Andean countries and Patagonia subregion  475

10.7.3 Soil biodiversity loss in the Andean countries and Patagonia subregion  477

10.7.4 Nutrient mismanagement in the Andean countries and Patagonia subregion  477

10.7.5 Salt accumulation in the Andean countries and Patagonia subregion  477

10.7.6 Soil pollution in the Andean countries and Patagonia subregion  478

10.7.7. Other threats in the Andean countries and Patagonia subregion  479

10.8 Trends in sustainable soil management for the Latin America and Caribbean region  480

References for Chapter 10  486

Chapter 11 | Regional assessment for the Near East and North Africa (NENA)  507

11.1 Regional overview  508

11.1.1 Characteristics of the region  508

11.1.2 Status summary from 2015 Status of the world's soil resources report  511

11.2 Changes in the direct and indirect drivers of soil functions  513

11.2.1 Indirect drivers: population growth  513

11.2.2 Direct drivers: land conversion  513

11.3 Status and trend of threats to soil functions in the Near East and North Africa (NENA) region  520

11.3.1 Soil erosion in the Near East and North Africa region  520

11.3.2 Soil carbon loss in the Near East and North Africa region  527

11.3.3 Soil biodiversity loss in the Near East and North Africa region  530

11.3.4 Nutrient mismanagement in the Near East and North Africa region  532

11.3.5 Salt accumulation in the Near East and North Africa region  538

11.3.6 Soil pollution in the Near East and North Africa region  541

11.4 Trends in sustainable soil management  549

11.4.1 Summary of state of and trend in sustainable soil management  549

11.4.2 Priorities for sustainable soil management  552

References for Chapter 11  554

Chapter 12 | Regional assessment for North America region  565

12.1 Regional overview  565

12.1.1 Characteristics of the region  565

12.1.2 Summary of status and trend from the 2015 Status of the world's soil resources report  567

12.2 Changes in the drivers of threats to soil functions  568

12.2.1 Overall population and urban population growth  568

12.2.2 Land-use change  568

12.2.3 Nutrient management  570

12.3 Regional status and trend of threats to soil functions for North America region  571

12.3.1 Soil erosion in the North America region  571

12.3.2 Nutrient mismanagement in the North America region  581

12.3.3 Ecoregional assessment of soil carbon change in the North America region  593

12.3.4 Soil biodiversity loss in the North America region  602

12.3.5 Urbanization and soil sealing  607

12.4 State and trends in sustainable soil management  613

References for Chapter 12  617

Sources for Figure 12.8  631

Chapter 13 | Regional assessment for the Southwest Pacific region  633

13.1 Regional overview  633

13.1.1 Characteristics of the region and subregions  633

13.1.2 Summary of state from 2015 State of the World's Soil Resources report  639

13.2 Changes in the drivers of threats to soil functions  640

13.2.1 Population growth  640

13.2.2 Land-use changes  641

13.2.3 Nutrient management  645

13.2.4 Other drivers in the Pacific Island countries  646

13.3 Regional status and trend of threats to soil functions for Australia  647

13.3.1 Indigenous Peoples' viewpoint  647

13.3.2 Soil erosion in Australia  647

13.3.3 Soil carbon loss in Australia  650

13.3.4 Soil biodiversity loss in Australia  653

13.3.5 Nutrient mismanagement in Australia  654

13.3.6 Salt accumulation in Australia  657

13.3.7 Soil pollution in Australia  660

13.3.8 Urbanization and soil sealing in Australia  661

13.3.9 Soil governance in Australia  662

13.4 Regional status and trend of threats to soil functions for New Zealand  664

13.4.1 Indigenous Peoples' viewpoint  664

13.4.2 Soil erosion in New Zealand  665

13.4.3 Soil carbon loss in New Zealand  665

13.4.4 Nutrient mismanagement in New Zealand  666

13.4.5 Soil pollution  667

13.4.6 Urbanization and soil sealing  668

13.4.7 Other topics: Soil monitoring to assess sustainability of land uses in New Zealand  669

13.4.8 Other comments  669

13.5 Regional status and trend of threats to soil functions for the Pacific Island countries subregion  670

13.5.1 Indigenous Peoples' viewpoint  670

13.5.2 Characteristics of the Pacific Island countries subregion  671

13.5.3 Soil erosion in the Pacific Island countries subregion  671

13.5.4 Soil carbon loss in the Pacific Island countries subregion  672

13.5.5 Soil biodiversity loss in the Pacific Island countries subregion  672

13.5.6 Nutrient mismanagement in the Pacific Island countries subregion  672

13.5.7 Salt accumulation in the Pacific Island countries  673

13.5.8 Soil pollution in the Pacific Island countries  673

13.5.9 Urbanization and soil sealing in the Pacific Island countries subregion  674

13.5.10 Climate change impacts in the Pacific Island countries subregion  675

13.5.11 Examples of innovative sustainable soil management practices in the Pacific Island countries subregion  675

13.6. Progress in and impediments to the adoption of sustainable soil management  677

13.6.1 Summary of state of and trend in sustainable soil management  677

13.6.2 Recommendations for future priorities for action  681

References for Chapter 13  683

Chapter 14 | Regional assessment for the sub-Saharan Africa region  701

14.1 Regional overview  702

14.1.1 Characteristics of the region and subregions  702

14.1.2 Summary of state from 2015 Status of the world's soil resources report  708

14.2 Changes in the drivers of threats to soil functions  710

14.2.1 Population growth  710

14.3 Regional state and trend of threats to soil functions for the equatorial forest and deciduous woodland subregions  720

14.3.1 Introduction  720

14.3.2 Soil erosion in the equatorial forest and deciduous woodland subregions  720

14.3.3 Soil carbon loss in the equatorial forest and deciduous woodland subregions  722

14.3.4 Soil biodiversity loss in the equatorial forest and deciduous woodland subregions  723

14.3.5 Nutrient mismanagement in the equatorial forest and deciduous woodland subregions  723

14.3.6 Soil physical deterioration in the equatorial forest and deciduous woodland subregions  724

14.3.7 Urbanization and soil sealing in the equatorial forest and deciduous woodland subregions  725

14.3.8 Soil pollution in the equatorial forest and deciduous woodland subregions  726

14.4 Regional status and trend of threats to soil functions for the savannah and highlands and desert and semi-desert subregions  727

14.4.1 Introduction  727

14.4.2 Soil erosion in the savannah and highlands and desert and semi-desert subregions  727

14.4.3 Soil carbon loss in the savannah and highlands and desert and semi-desert subregions  729

14.4.4 Soil biodiversity loss in the savannah and highlands and desert and semi-desert subregions  730

14.4.5 Nutrient mismanagement in the savannah and highlands and desert and semi-desert subregions  730

14.4.6 Salt accumulation in the savannah and highlands and desert and semi-desert subregions  733

14.4.7 Soil pollution in the savannah and highlands and desert and semi-desert subregions  734

14.4.8 Urbanization and soil sealing in the savannah and highlands and desert and semi-desert subregions  734

14.4.9 Other threats in the savannah and highlands and desert and semi-desert subregions  735

14.5 Regional status and trend of threats to soil functions for the islands of Africa subregion  737

14.5.1 Introduction  737

14.5.2 Soil erosion in the islands of Africa subregion  737

14.5.3 Soil carbon loss in the islands of Africa subregion  737

14.5.4 Soil biodiversity loss in the islands of Africa subregion  738

14.5.5 Nutrient mismanagement in the islands of Africa subregion  738

14.6 Trends in sustainable soil management  740

14.6.1 Summary of state of and trend in threats to soil functions  740

14.6.2 Progress and impediments in the adoption of sustainable soil management  741

14.6.3 Recommendations for future priorities for action  743

References for Chapter 14  744

Chapter 15 | Global assessment of state and trend in the adoption of sustainable soil management practices  759

15. 1 Overview of the methodology for assessing the state and trend in the adoption of sustainable soil management practices  759

15.1.1 Assessment of confidence  760

15.2 Global assessment of state and trend in the adoption of sustainable soil management practices to address threats to soil functions  763

15.3 Global state and trend for individual soil threats  765

15.3.1 Soil erosion  765

15.3.2 Loss of soil organic carbon  770

15.3.3 Nutrient mismanagement  775

15.3.4 Loss of soil biodiversity  782

15.3.5 Salt accumulation  787

15.3.6 Soil pollution  792

15.3.7 Urbanization and soil sealing  796

15.3.8 Other threats to soil functions  800

15.4 Limitations of current report and suggestions for future improvements  803

References for Chapter 15  804

Chapter 16 | Turning knowledge into action: breaking barriers to sustainable soil management  811

16.1 Introduction  811

16.2 The global adoption of sustainable soil management and the challenges hindering progress  812

16.3 New challenges, familiar solutions: fostering collaborative commitment and shared responsibilities to promote sustainable soil management  816