Phosphorus in Agriculture: 100 % Zero (eBook)

Prof. Ewald Schnug, Institute for Crop and Soil Science, Julius Kühn-Institut, Germany - EditorProf. Luit J. De Kok, University of Groningen, Laboratory of Plant Physiology, The Netherlands - Editor

Preface 6
“Phosphora” 8
About the Artist 9
Contents 11
1 Urgent Need for Action in the Baltic Sea Area 13
Abstract 13
Introduction 13
Action Already Taken 14
HELCOM Shows Way for Baltic Sea Protection 15
The Baltic Sea Action Plan Sets the Protection Targets 15
PLC-5 Shows Some Positive Signs 17
References 18
2 The Enigma of Fertilizer Phosphorus Utilization 19
Abstract 19
Introduction 19
Fate of Fertilizer P in Agro-ecosystems 21
Turnover of Inorganic P in Soils 21
Turnover of Organic P in Soils 23
P-Losses from Agro-ecosystems 24
The Utilization Coefficient of P in Fertilizers and Its Significance for Fertilization 24
Empirical Methods to Determine the Fertilizer Nutrient Utilization Efficiency 29
Conclusions 33
References 34
3 Fate of Fertilizer P in Soils: Inorganic Pathway 39
Abstract 39
Inorganic Phosphorus in Soil Solution 39
Reactions Between P and the Inorganic Soil Constituents 41
Inorganic Fractions of P in Soil 42
Where Does the Fertilizer P Go in the Soil? 44
Phosphorus Sorption Capacity of Soil 46
Degree of P Saturation 47
P Stock and P Supply to Plants 49
References 50
4 Fate of Fertilizer P in Soils—The Organic Pathway 53
Abstract 53
Introduction 54
The Actors of the “Organic Pathway” and Their Dynamics 55
The Role of Plants 56
The Role of Microorganisms 57
Organic P Forms 58
Importance of the “Organic Pathway” for the P Cycle in Natural Ecosystems 58
Importance of the “Organic Pathway” for P Use 58
Importance of the “Organic Pathway” for P Losses 60
Importance of the “Organic Pathway” for P Availability and Losses in Western and Northern European Agricultural Systems 60
Estimating the P Use Efficiency in Agricultural Systems 61
Importance of the “Organic Pathway” in Determining P Use Efficiency 62
Importance of the “Organic Pathway” for P Losses 68
References 70
5 Determination of Plant Available P in Soil 74
Abstract 74
Introduction 75
Why Is Plant Available P Determined? 75
What Does the Term “Plant Available P” Stand for? 76
Determination of Plant Available P 77
Characteristics of Various Extraction Methods 81
Criteria for a Method to Extract Plant Available P from Soil 81
Methods Involving Strong Acids 82
Methods Involving Bicarbonate 82
Development of Methods Involving Lactate 83
Acetate Solutions as Extractants of Soil P 84
Non-destructive Methods for the Estimation of Plant-Available P 85
Different Methods—Different Results 89
Difficulties in the Comparison of Results Across Borders 93
Establishing the Biological Significance of STP Values and Formulation of Fertiliser Recommendations 95
Conclusions 98
References 99
6 Assessing the Plant Phosphorus Status 105
Abstract 105
Introduction 105
Soil Phosphorus Reserves 106
Factors Affecting Phosphorus Acquisition of Crop Plants 107
Root Anatomy 107
Farm Management Practices 108
Regulatory Aspects of Phosphorus Uptake by Crop Plants 110
Functions of Phosphorus in Crop Plants 111
Phosphorus Supply and Plant Health 112
Symptomatology of Phosphorus Deficiency and Toxicity 113
Evaluation of Diagnostic Phosphorus Values in Crop Plants 115
Analytical Methods 116
Assessment of Critical Nutrient Values and Ranges 117
Phosphorus Fertilization 123
Spatial Variation of Soil and Crop Parameters 124
Variable Rate Fertilization 125
Manure—Resource or Removal? 126
Nutrient Mining and Phosphorus Phytomining—Dealing with Extremes 128
References 129
7 P Solubility of Inorganic and Organic P Sources 136
Abstract 136
Introduction 137
Criteria for the Evaluation of Agronomic Efficiency of P Fertilizers 138
Chemical Extraction Procedures for Estimating P Solubility of Mineral Fertilizers 139
European and German Fertilizer Legislation 139
Scope of the Procedures 140
Plant Availability of Different P Compounds in Vegetation Trials 141
Correlations Between Chemical Extractions and Plant Uptake 143
Water 143
Neutral Ammonium Citrate (NAC)/Alkaline Ammonium Citrate (AAC) 143
Citric Acid 144
Formic Acid 145
Requirements for a Chemical Extraction Procedure to Characterize Plant Availability of Fertilizer P 146
Applicability of Standard Procedures for Recycling Fertilizers 147
Applicability for Organic P Fertilizers? 152
P Forms in Organic Fertilizers 153
Chemical Extractions for Estimating P Solubility of Organic Fertilizers 153
Correlation of Extracted P with P Uptake by Plants 155
Conclusions 158
References 159
8 Variability of P Uptake by Plants 164
Abstract 164
Introduction 164
Common P Coefficients in Use 166
Variability of P Uptake 169
Variability Between Cultivars and Genotypes 169
Spatial Variability of P Uptake by Crops 175
Conclusions 180
References 181
9 Management Options for an Efficient Utilization of Phosphorus in Agroecosystems 188
Abstract 188
Catch Cropping and Mixed Cropping 188
Catch Cropping 189
Mixed Cropping 191
Beneficial Microorganisms and Organic Matter Management 193
Recycling Products (Biogas Digestates and Biomass Ashes) 195
Biogas Digestates 195
Biomass Ashes 197
References 198
10 Phosphorus—The Predicament of Organic Farming 203
Abstract 203
Introduction 204
Organic Farming on Sites with Different Fertilization History 204
P Budgets of Organic Farming Systems Are Often Negative 205
Soil P Tests to Detect the Need for P Inputs 207
Mobilising Soil P Reserves by Biological Measures 208
Using Suitable Root Systems and Adapted Crop Rotations 208
Enhancing Soil Microbial Activity 210
P Acquisition from the Subsoil 210
Suitable Fertilizers Must Be Discussed 212
Conclusion for Research Needs and Perspectives 215
References 216
11 Utilization of Phosphorus at Farm Level in Denmark 222
Abstract 222
Legal Framework for Phosphorus Management in Denmark 222
Recommendations for P Fertilization in Denmark 224
Determination of the Correction Factor for Plant-Available P in Soil 225
Calculation of the Uptake of P by Crops (Above Soil Parts Only) 226
Correction for Crop Type 227
Correction for P Balance in the Crop Rotation 228
Calculation P Demand with the Fertilizer Planning Software Mark-Online 228
Effect of the P Form in Fertilizers 228
Use of Waste Products for P Fertilization 229
P Status in Danish Soils 229
P Balance on National, Regional and Farm Level in Denmark 230
National Level 230
P Balance on a Regional Level in Denmark 232
Farm Balances of P 233
Conclusions for Improving the P Balance of Farms 235
References 235
12 Trace Element Contaminants and Radioactivity from Phosphate Fertiliser 237
Abstract 237
Introduction 238
Types of Phosphate Fertiliser 238
Phosphate Rock 238
Phosphoric Acid Production 241
Superphosphate 241
Triple Superphosphate 242
Ammonium Phosphate/Diammonium Phosphate 242
Ammonium Polyphosphate 243
Blended Fertilisers 243
Phosphogypsum 243
General Comment 245
Risk Analysis of Trace Elements in Phosphate Fertilisers and Phosphate Rocks 245
A Quantitative Ranking Model 245
Quantity of a Contaminant 246
Mobility of a Contaminant 247
Toxicity 252
Radioactivity 253
Secondary Photoelectron Effect 254
Ranking 256
Potential Issues for Resource Managers 258
Potential Issues 258
Guidelines 260
Manage the Risk 261
Fertiliser Management 262
Environmental Monitoring and Research 262
Remediation 262
Concluding Remarks 264
References 265
13 Organic Xenobiotics 273
Abstract 273
Agricultural Use of Farmyard Manure, Slurry, Organic Waste Products and Recycled Materials 274
Relevant Classes of Organic Contaminations in Organic Fertilizer Materials 277
Human and Veterinary Pharmaceuticals 278
Antibiotics 278
Development of Antimicrobial Resistance 279
Antibiotics as Feed Additives 281
Excretion of Antibiotics 282
Effects of Antibiotics in the Environment Shown Exemplary for Tetracyclines 282
Toxic Effects of Antibiotics on Aquatic Species 284
Uptake of Antibiotics into Plants 286
Endocrine Disruptors 287
Sources of Compounds with Oestrogenic Activity 288
Environmental EDC Concentrations and Physiological Effects 289
Degradation of Compounds with Oestrogenic Activity 292
Contamination of Organic P Fertilizers by Antibiotics and EDCs 293
Evaluation of Technical Procedures to Remove Organic Contaminants from Fertilizer Materials 301
Future Prospects and Research Needs 303
Acknowledgment 305
References 305
14 Energy Neutral Phosphate Fertilizer Production Using High Temperature Reactors 314
Abstract 314
Introduction 314
High Temperature Gas-Cooled Reactors (HTGRs) 316
Energy Neutral Phosphate Fertilizer Processing Employing High Temperature Reactors 318
Discussion 319
Conclusions 320
References 320
15 Justice and Sustainability: Normative Criteria for the Use of Phosphorus 322
Abstract 322
Theoretical Background—Ethical and Legal 322
Human Rights—Only Subordinate and Vague “Protection Obligations” with Regard to Sustainability? The Traditional Legal Point of View in the EU and Germany 325
Intergenerational and Global Scope of Human Rights, Protecting the Conditions of Freedom, and Multipolarity of Freedom 327
The Example of Phosphorus 331
References 335
16 Governance Instruments for Phosphorus Supply Security 336
Abstract 336
Phosphorus as a Scarce and Environmentally Relevant Resource: Call for Action? 337
EU Policy Approaches to Phosphorus 341
Issues in Existing Legal Approaches 344
Phosphorus Governance Through Economic Instruments 346
Conclusion 349
Acknowledgments 349
References 350
Index 353