Preface xii 1 Cover Crops and Soil Ecosystem Services 1 1.1 Cover Crops 1 1.2 Soil Ecosystem Services 4 1.3 Cover Crops and Soil Ecosystem Services 6 1.4 Summary 8 References 9 2 Cover Crop Biomass Production 12 2.1 Cover Crops and Biomass 12 2.2 Aboveground Biomass Production 13 2.2.

1 Temperate Regions 13 2.2.2 Semiarid Temperate Regions 14 2.2.3 Tropical and Subtropical Regions 15 2.3 Belowground Biomass Production 17 2.4 Threshold Level of Biomass Production 18 2.5 Management Practices that Affect Biomass Production 18 2.

5.1 Planting Early 19 2.5.1.1 Interseeding 19 2.5.1.2 Planting after Summer Crop Harvest 21 2.

5.1.3 Planting after Corn Silage or Short- Growing Season Crop Harvest 23 2.5.2 Terminating Late 23 2.5.3 Cover Crop Mixes 25 2.5.

4 Seeding Rate 26 2.5.5 Planting Method 26 2.5.6 Tillage and Cropping Systems 27 2.5.7 Soil Texture and Number of Years in Cover Crops 28 2.5.

8 Irrigation and Fertilization 28 2.6 Summary 29 References 30 3 Soil Health 35 3.1 Soil Health 35 3.2 Cover Crops and Soil Health 37 3.2.1 Soil Physical Properties 37 3.2.1.

1 Soil Compaction 37 3.2.1.2 Soil Structure 39 3.2.1.3 Water Infiltration 40 3.2.

1.4 Temperature 42 3.2.2 Soil Chemical Properties 42 3.2.3 Soil Biological Properties 43 3.2.3.

1 Microorganisms 44 3.2.3.2 Macroorganisms 45 3.3 Interconnectedness of Soil Health Parameters 47 3.4 Managing Soil Health 47 3.4.1 Biomass Production 48 3.

4.2 Time after Cover Crop Introduction 48 3.4.3 Cover Crop Species and Mixes 49 3.4.4 Tillage System 50 3.4.5 Initial Soil Condition 51 3.

5 Summary 51 References 52 4 Water Erosion 58 4.1 Overview 58 4.2 Runoff 59 4.3 Sediment Loss 62 4.4 Nutrient Loss 63 4.5 Soil Carbon Loss 63 4.6 A Leading Factor of Water Erosion: Biomass Production 64 4.7 Cover Crops and Erosion- Prone Systems 65 4.

7.1 Low- Biomass Producing Cropping Systems 66 4.7.2 Corn Silage and Seed Corn 66 4.7.3 Crop Residue Removal 68 4.7.4 Orchard Crops 68 4.

8 Summary 69 References 69 5 Wind Erosion 73 5.1 Extent of Wind Erosion 73 5.2 Soil Loss 74 5.3 Soil Erodibility 76 5.4 Managing Wind Erosion 78 5.4.1 Biomass Production 78 5.4.

2 Cover Crop Species 79 5.4.3 Growth Stage and Seeding Rate 80 5.4.4 Crop and Tillage Systems 81 5.4.5 Climate 82 5.5 Summary 82 References 83 6 Nutrient Losses 85 6.

1 Implications of Nutrient Losses 85 6.2 Nutrient Leaching 86 6.3 Dissolved Nutrients in Runoff 89 6.4 Nutrient Release from Cover Crops 90 6.5 Management Implications 92 6.6 Nutrient Stratification 93 6.7 Summary 94 References 94 7 Soil Gas Emissions 97 7.1 Carbon and Nitrogen Emissions 97 7.

2 Carbon Dioxide 98 7.3 Nitrous Oxide 99 7.4 Methane 100 7.5 Factors Affecting Soil Gas Emissions 100 7.5.1 Cover Crop Species 101 7.5.2 Biomass Production 102 7.

5.3 Nitrogen Fertilization 103 7.5.4 Tillage and Cropping System 104 7.5.5 Measurement Time 105 7.5.6 Soil Texture and Climate 106 7.

6 Summary 106 References 107 8 Carbon Sequestration 109 8.1 The Need for Carbon Sequestration 109 8.2 Rates of Carbon Sequestration 110 8.3 Topsoil Versus Subsoil Carbon Sequestration 112 8.4 Managing Carbon Sequestration 114 8.4.1 Biomass Production 114 8.4.

2 Cover Crop Species and Mixes 116 8.4.3 Years after Cover Crop Adoption 117 8.4.4 Initial Soil Carbon Level 118 8.4.5 Tillage Systems 119 8.4.

6 Soil Texture 120 8.4.7 Topographic Characteristics 120 8.4.8 Climate 121 8.5 Cropping System Carbon Footprint 122 8.6 Strategies to Enhance Cover Crop Potential to Sequester Carbon 122 8.7 Summary 124 References 125 9 Soil Water 128 9.

1 Soil Water Management 128 9.2 High Precipitation Regions 129 9.3 Low Precipitation Regions 129 9.4 Mechanisms of Soil Water Storage with Cover Crops 132 9.5 Water Management 134 9.5.1 Biomass Production 135 9.5.

2 Timing of Cover Crop Termination 136 9.5.3 Tillage System 136 9.5.4 Soil Texture 137 9.6 Summary 138 References 138 10 Weed Management 141 10.1 Cover Crops and Weeds 141 10.2 Weed Suppression 142 10.

3 Managing Weeds 144 10.3.1 Biomass Production and Surface Cover 145 10.3.2 Cover Crop Species and Mixes 146 10.3.3 Tillage System 148 10.3.

4 Climate 148 10.4 Summary 149 References 150 11 Soil Fertility 151 11.1 Soil Fertility Management 151 11.2 Organic Matter 152 11.2.1 Nitrogen 154 11.2.2 Nitrogen Scavenging 154 11.

2.3 Reduction of Nitrogen Losses 154 11.2.4 Nitrogen Fixation 155 11.3 Phosphorus 156 11.4 Other Nutrients 158 11.5 Soil pH 158 11.6 Cation Exchange Capacity 160 11.

7 Carbon to Nitrogen Ratio 161 11.8 Summary 163 References 163 12 Crop Yields 167 12.1 Multi- functionality of Cover Crops 167 12.2 Crop Yields 168 12.3 Climate 169 12.3.1 Cool and Warm Climates 169 12.3.

2 Water- Limited Regions 169 12.4 Factors Affecting Crop Production 170 12.4.1 Cover Crop Species 170 12.4.2 Nitrogen Fertilization 171 12.4.3 Biomass Production 171 12.

4.4 Planting Time and Method 172 12.4.5 Termination Timing 174 12.4.6 Cover Crop Mixes 174 12.4.7 Years after Cover Crop Adoption 175 12.

4.8 Tillage Systems 176 12.4.9 Soil Texture 176 12.5 Summary 177 References 177 13 Grazing and Harvesting 180 13.1 Cover Crop Biomass Removal 180 13.2 Grazing 181 13.2.

1 Soil Compaction 181 13.2.2 Water Infiltration 184 13.2.3 Soil Carbon Dynamics and Sequestration 185 13.2.4 Crop Yields 186 13.3 Minimizing Potential Grazing Impacts 187 13.

3.1 Amount of Biomass Removal 188 13.3.2 Stocking Rate 189 13.3.3 Years under Grazing 189 13.3.4 Tillage 190 13.

3.5 Soil Water Content 190 13.4 Harvesting 191 13.5 Grazing and Harvesting: An Added Benefit from Cover Crops? 193 13.6 Summary 194 References 194 14 Economics 197 14.1 Cover Crops and Farm Profits 197 14.2 Economic Analysis 198 14.2.

1 Grazing and Harvesting 199 14.2.2 Weed Suppression 201 14.2.3 Nitrogen Credit 202 14.2.4 Soil Carbon Credit 203 14.2.

5 Crop Residue Harvesting 204 14.2.6 Valuation of Other Ecosystem Services 204 14.3 Site- Specificity of Economic Benefits 205 14.4 Summary 206 References 206 15 Adaptation to Extreme Weather 210 15.1 Extreme Weather Events 210 15.2 Droughts 211 15.3 Floods 212 15.

4 Precipitation Extremes 214 15.5 Dust Storms 217 15.6 Temperature Extremes 217 15.7 Soil Resilience 218 15.8 Summary 220 References 221 16 Opportunities, Challenges, and Future of Cover Crops 224 16.1 Opportunities 224 16.1.1 Ecosystem Services 224 16.

1.2 Biomass Production 227 16.1.3 Economics 228 16.1.4 Fluctuating Climates 229 16.2 Challenges 229 16.2.

1 Ecosystem Services 230 16.2.1.1 Biomass Production 230 16.2.1.2 Soil Properties 231 16.2.

1.3 Carbon Sequestration 232 16.2.1.4 Dissolved Nutrients 232 16.2.1.5 Crop Yields 233 16.

2.1.6 Economics 233 16.2.1.7 Fluctuating Climates 234 16.3 Remaining Questions 234 16.4 The Future of Cover Crops 236 16.

5 Summary 237 References 238 Appendix I: Common and Scientific Names Used in the Book 241.