Front Cover; Advances in Agronomy, Volumes 16; Copyright Page; Contributors to Volumes 16; Preface; Contents; Chapter 1. Field Plant Physiology; I. Introduction; II. Characterization of the Environment; III. Environmental Elements and Plant Growth; IV. Controlled Environment Facilities as a Supplement to Field Research; References; Chapter 2. Crop Response to Fertilizers in Relation to Content of ""Available"" Phosphorus; I. Introduction; II. Status of Chemical Methods in the United States and Other Countries; III. Chemical and Physical Nature of Fertilizers Marketed in the United States.

IV. Crop Response Results Prior to 1950V. Recent Crop Response Results; VI. Problems Concerned with Nonorthophosphates and Other Fertilizers; VII. In Conclusion; References; Chapter 3. Objectives in Corn Improvement; I. Introduction; II. Hybrid Corn and Yield; III. The Offense and the Defense; IV. Culture and Improvement; V. Breeding for Industrial Uses and Nutritive Value; VI. Parent Stocks; VII. Exotic Germ Plasm; VIII. The Cytoplasm; IX. Tetraploid Corn; X. Summary and Conclusions; References; Chapter 4. Salinity in Relation to Irrigation; I. Introduction; II. Salinity of Irrigation Waters.

III. Effect of Salts on SoilsIV. Effect of Salts on Crops; V. Reclamation of Salt-Affected Lands; VI. Management Practices for Salt-Affected Land; VII. Conclusions; References; Chapter 5. Response of Plants to the Physical Effects of Soil Compaction; I. Causes of Soil Compaction; II. Compaction Effects on Soil Productivity; III. Plant Response to Soil Compaction; IV. Experimental Difficulties; V.A Mechanistic Study of Compaction Effects on Plant Growth; VI. Outlook; References; Chapter 6. Nitrate Accumulation in Crops and Nitrate Poisoning in Animals; I. Introduction.

II. Recognition of Nitrate as a Toxic AgentIII. Accumulation of Nitrate by Plants; IV. Postharvest Losses; V. Toxicity of Nitrate to Animals; VI. Conclusions; References; Chapter 7. Characterizing Soil Oxygen Conditions with a Platinum Microelectrode; I. Introduction; II. Polarography; III. Problems Associated with the Use of Platinum Microelectrodes in Soils; IV. Relationships between Oxygen Diffusion Rates and Biological Responses; V. Results of Field Measurements; VI. Summary; References; Chapter 8. Some Parameters of Population Variability and Their Implications in Plant Breeding.

I. IntroductionII. The Genetics of Predominantly Self-Pollinated Populations; III. The Exploitation of Exotic Variability; IV. Variability within Agricultural Varieties; V. Summary; References; Chapter 9. Amorphous Inorganic Materials in Soils; I. Introduction; II. Nature and Occurrence; III. Methods of Detection and Estimation; IV. Origin of Amorphous Material in Soil; V. Relationships between Amorphous Inorganic Material and Specific Physical and Chemical Properties; VI. Summary; References; Author Index; Subject Index; Index of Contributors Volumes 1-15; Keyword Index Volumes 1-15.