Front Cover; Advances in Agronomy, Volume 35; Copyright Page; Contents; Contributors; Preface; CHAPTER 1. THE RHIZOTRON AS A TOOL FOR ROOT RESEARCH; I. Introduction; II. Physical Designs: General Types; III. Construction Details and Design Features; IV. Some Techniques for Observing and Recording Root System Parameters; V. Experimental Design: Data Acquisition and Analysis; VI. Summary: Advantages and Disadvantages of Rhizotrons for Use in Root Investigations; References; CHAPTER 2. THE CONSERVATION AND USE OF RICE GENETIC RESOURCES; I. Introduction; II. Diversity in Rice Genetic Resources.

III. Recent Efforts in Genetic ConservationIV. Dissemination and Evaluation of Germ Plasm; V. Preservation of Germ Plasm; VI. Use of Germ Plasm; VII. Endeavors for the Future; References; CHAPTER 3. THE EFFECTS OF LOW TEMPERATURE ON Zea mays; I. Introduction; II. Freezing Injury; III. Damage by Low Nonfreezing Temperatures; IV. Growth and Development at Suboptimal Temperatures; V. Breeding for Low-Temperature Adaptation; VI. Summary; References; CHAPTER 4. AGRICULTURAL USE OF PHOSPHORUS IN SEWAGE SLUDGE; I. Introduction; II. Concentration of Phosphorus in Sludges.

III. Agricultural Use of Phosphorus in SludgesIV. Summary and Conclusions; References; CHAPTER 5. SUBTERRANEAN CLOVER IN THE UNITED STATES; I. Introduction; II. Potential Use of Subclover; III. Breeding Subclover; IV. Seed Characteristics; V. Nitrogen Fixation; VI. Fertilization and Nutrition; VII. Climatic Variations; VIII. Establishment and Management; IX. Morphological Characteristics; X. Summary; References; CHAPTER 6. PREDICTING CROP PRODUCTION AS RELATED TO PLANT WATER STRESS; I. Introduction; II. Review of the Litetrature; III. Measuring ET; IV. Estimating ET; V. Estimating Yield.

VI. Growth Stage EffectsVII. Rasmussen and Hanks Spring Wheat Model; VIII. Rasmussen and Kanemasu Winter Wheat Model; IX. Hill, Johnson, and Ryan Model; X. Morgan, Biere, and Kanemasu Model for Corn; XI. Other Models with Moisture Stress Included; XII. Summary; References; CHAPTER 7. IRON NUTRITION OF PLANTS IN CALCAREOUS SOILS; I. Introduction; II. Soil Iron Compounds and Methods for Their Extraction; III. Iron Nutrition of Plants; IV. Correction of Iron Deficiency; References; CHAPTER 8. NITROGEN TRANSFORMATIONS IN WETLAND RICE SOILS; I. Introduction; II. Chemical Nature of Soil Nitrogen.

III. Physical and Physicochemical Processes Relevant to Nitrogen TransformationsIV. Biochemical Nitrogen Transformations; V. Fate of Fertilizer Nitrogen; VI. Regulating Nitrogen Transformation Processes; VII. Unresolved Challenges; References; Index.