Front Cover; Advances in Agronomy, Volume 12; Copyright Page; Contents; Contributors; Preface; Chapter 1. The Clay Fraction of Soils; I. Introduction; II. Crystal Structure and Morphology of Minerals in the Clay Fraction; III. Origin of Minerals of the Clay Fraction; IV. Identification and Quantitative Estimation of Clay Minerals; V. Effects of the Clay Fraction on Soil Chemical Reactions; VI. Effects of the Clay Fraction on Soil Physical Reactions; VII. Summary; References; Chapter 2. Technological Advances in Grass and Legume Seed Production and Testing.

I. Maintaining Varietal Purity, and Cultural and Management PracticesII. Insect Pollination of Forage Legumes; III. Insects Affecting Production of Forage Seed; IV. Disease Control in Forage Seed Production; V. Quality Determination of Forage Seeds; References; Chapter 3. Fertilizers in Forestry; I. Foreword; II. Soil Fertility in Forest Nurseries; III. Fertilization of Forest Trees; References; Chapter 4. Agronomy in the Southwest United States; I. Introduction; II. Regional Characteristics; III. Factors Affecting Southwestern Agriculture; IV. Field Crops; V. Fruit and Vegetable Crops.

VI. SummaryReferences; Chapter 5. Mineral Nutrition of Soybeans; I. Introduction; II. Growth Analysis; III. Nitrogen; IV. Phosphorus; V. Potassium; VI. Calcium; VII. Magnesium; VIII. Sulfur; IX. Iron; X . Manganese; XI. Boron; XII. Zinc; XIII. Copper and Other Elements; XIV. The Future of Soybean Nutrition; References; Chapter 6. Physiology of the Soybean; I. Introduction; II. Germination; III. Root Growth and Nodulation; IV. Top Vegetative Growth; V. Flowering; VI. Pod and Seed Development; VII. Discussion; References; Chapter 7. Water Infiltration into Soils; I. Introduction.

II. Factors Influencing Infiltration Rates and Permeability of SoilsIII. Methods Utilizing a Sprinkling Device for Infiltration and Erosivity Measurements; IV. Cylinder Infiltrometers; V. Basin Methods; VI. Watershed Hydrograph Methods; VII. Infiltration and Permeability Measurements on Undisturbed Soil Cores and Columns of Disturbed Soil; VIII. Theoretical Considerations; References; Chapter 8. Red Clover; I. Introduction; II. Origin, Early History, and Distribution; III. Taxonomy; IV. General Morphology; V. Physiology and Ecology; VI. Diseases and Nematodes.

VII. Destructive Insects and MitesVIII. Weeds of Red Clover Fields; IX. Breeding and Genetics; X. Uses of Red Clover; XI. Growing Red Clover; References; Author Index; Subject Index.