Advances in agronomy. V.89 /

Cover Page 1
Title Page 4
Copyright Page 5
Contents 6
Contributors 12
Preface 16
Chapter 1: Advances in the Characterization of Phosphorus in Organic Wastes: Environmental and Agronomic Applications 17
I. Introduction 18
II. Types of Organic Wastes 21
A. Agricultural Wastes 21
B. Municipal Wastes 24
III. Factors Affecting Phosphorus Composition in Organic Wastes 25
A. Dietary Effects 25
B. Organic Wastes Handling Effects 29
IV. Methods for Characterizing Phosphorus in Organic Wastes 32
A. Total Phosphorus 32
B. Water Extractable Phosphorus 34
C. Physicochemical Fractionation 37
D. Sequential Phosphorus Fractionation 40
E. Enzyme Hydrolysis 46
F. Nuclear Magnetic Resonance Spectroscopy 51
G. X-Ray Absorption Near Edge Structure Spectroscopy 62
V. Summary 77
References 79
Chapter 2: Wheat Genetics Resource Center: The First 25 Years 89
I. Introduction 90
II. Wheat Genetic Resources 92
A. Taxonomic Considerations 92
B. Collection and Maintenance 93
C. Evaluation and Genetic Diversity Analysis of the WGRC Collection 97
D. Distribution of the Collection 97
III. Advances in Molecular Cytogenetics of Wheat and Triticeae Species 98
IV. Genomic Breeding and Intergenomic Transfers by Chromosome Engineering 100
A. The Journey from Genome Sharing to Gene Donors 100
B. Intergenomic Transfers by Chromosome Engineering 116
V. Documentation of Genetic Novelty 122
VI. Germplasm for Wheat-Breeding Programs 131
VII. The Next 25 Years 132
Acknowledgments 134
References 134
Chapter 3: Cultivation of Stevia [Stevia rebaudiana (Bert.) Bertoni]: A Comprehensive Review 153
I. Introduction 154
II. Agricultural History 155
III. Agricultural Impact and Use 156
IV. Botanical Description 158
A. Growth Pattern 158
B. Plant Morphological Variation 159
C. Root System 159
D. Stem 159
E. Leaves 159
F. Flowers 160
G. Seeds 160
H. Sweet Glycoside Content in Plant Parts 161
V. Environmental Versatility 162
A. Geographic Distribution 165
B. Day Length/Photoperiod 166
C. Temperature 168
D. Light 168
VI. Cultivation 169
A. Seed Germination, Nursery, and Crop Establishment 169
B. Spacing/Crop Density 170
C. Vegetative Propagation 172
D. Nutrient Management 174
E. Crop-Weed Competition and Weed Management 176
F. Water Requirement 177
G. Soil Requirement 178
H. Harvest 178
I. Growth Regulators 178
J. Seed Production 180
K. Correlation Studies 180
L. Biotic Stresses 182
M. Crop Productivity 182
VII. Chemistry and Quality 183
VIII. Research Needs 184
Acknowledgments 185
References 185
Chapter 4: Assessing Soil Fertility Decline in the Tropics Using Soil Chemical Data 195
I. Introduction 196
II. Changes in Soil Chemical Properties 198
A. Additions, Removals, Transformations, and Transfers 199
B. Spatial Boundaries 200
C. Temporal Boundaries 201
III. Data Types 202
A. Expert Knowledge 202
B. The Nutrient Balance 203
C. Measured Change in Soil Chemical Properties: Type I Data 206
D. Measured Change in Soil Chemical Properties: Type II Data 207
E. Minimum Data Sets 207
IV. Soil Sampling, Soil Analysis, and Errors 209
A. Errors in Soil Sampling 209
B. Errors in Soil Handling and Storage 210
C. Errors in Soil Analysis 212
D. Soil Variation 213
V. Soil Chemical Changes and Nutrient Removal 216
A. Annual and Perennial Crops 216
B. Nutrients in the Roots and Crop Residues 218
VI. Presentations of Results 219
A. Rates of Change 222
B. Paired Sequential Samples 223
C. Bulk Density 224
D. Bulk Density Effects on Nutrient Stocks 225
VII. Interpretation of Results 227
A. Resilience and Reversibility 227
B. The Time-Lag Effect 229
C. Frequency, Period, and Time of Observation 230
VIII. Summary and Conclusions 232
Acknowledgments 233
References 233
Chapter 5: Nematode Interactions in Nature: Models for Sustainable Control of Nematode Pests of Crop Plants? 243
I. Introduction 244
II. Current Practices and Options in Nematode Control in Agriculture 246
A. Cropping Practices: Intercropping and Crop Rotation 246
B. Chemical Control 248
C. Biological Control 249
D. Organic Amendments and Suppressive Soils 252
E. Physical Control: Distance and Treatments 253
F. Genetically Resistant Crops 254
III. Nematodes in Natural Systems 255
A. Vegetation Processes: Succession, Diversity, and Invasiveness 256
B. Nematode Diversity, Abundance, and Dynamics in Nature: Food Web Interactions and Controls 257
C. From Resistance Genes to Red Queen Processes 258
D. Origin of Plant-Parasitic Nematodes; Impact of Agriculture and Intensification Processes 260
IV. Lessons from Looking Across the Fence 261
A. Theory-Driven Research Approach 261
B. Comparing Natural Systems, Tropical/Original Agriculture, and Intensive Agriculture 263
C. Biodiversity and Crop Protection 263
V. Discussions 264
VI. Conclusions 266
Acknowledgments 266
References 266
Chapter 6: Algorithms Determining Ammonia Emission from Buildings Housing Cattle and Pigs and from Manure Stores 277
Abbreviations 279
I. Introduction 280
II. Livestock Farming Practices 282
A. Housing 283
B. Manure Stores 284
C. Feedlots and Exercise Area 286
III. System Analysis 287
A. Nitrogen Flow 287
B. Ammonia and Manure 288
C. Concepts of Ammonia Release, Emission, and Dispersion 288
IV. Release and Transport Model 291
A. Sources 292
B. Transport of NH3 in Animal Houses 295
C. Transport from Unconfined Sources 300
D. Simple Gradient Approach 302
V. Manure Chemistry 303
A. Excretion 304
B. Urea Transformation to Ammonium 308
C. Transformation of N Between Inorganic and Organic Pools 309
D. Nitrification and Denitrification 311
E. pH Buffer System 313
F. Cation Exchange Capacity of Solid Matter in Manure 318
VI. Emission from Livestock Housing 319
A. Cattle Housing 319
B. Pig Housing 323
VII. Ammonia Emission from Outdoor Areas 329
A. Cattle Feedlots 329
B. Hardstandings 330
VIII. Emission from Outdoor Manure Stores 332
A. Slurry Stores 332
B. Solid Manure Stores 335
IX. Perspectives 337
Acknowledgments 279
References 339
Index 353