Front Cover; Advances in Agronomy, Volume 38; Copyright Page; Contents; Contributors; Preface; CHAPTER 1. REFLECTANCE PROPERTIES OF SOILS; I. Soil Color in Perspective; II. Instrumentation for Reflectance Measurements; III. Effects of Soil Constituents on Soil Reflectance; IV. Reflectance Properties of Soils in Their Environment; V. Applications of Soil Reflectance Measurements; References; CHAPTER 2. APPLICATION OF GEOSTATISTICS TO SPATIAL STUDIES OF SOIL PROPERTIES; I. Introduction; II. Nature of Soil Variability; III. Traditional Methods of Describing Soil Variability

IV. Regionalized Variable Theory and GeostatisticsV. Analysis of Spatial Dependence; VI. Interpolation by Kriging; VII. Perspectives: Future Use of Geostatistics in Soil Research; References; CHAPTER 3. THE INFLUENCE OF SOIL STRUCTURE ON WATER MOVEMENT, CROP ROOT GROWTH, AND WATER UPTAKE; I. Introduction; II. Soil Structure: Components of the Soil-Pore System; III. Stability of the Pore System; IV. Water Flow in Agricultural Soils; V. Patterns of Root Growth; VI. Water Uptake by Roots; VII. Speculation: Are We Measuring and Averaging at Consistent Scales?; VIII. Summary; References

CHAPTER 4. GASEOUS HYDROCARBONS IN SOILI. Introduction; II. Formation, Transformation, and Importance of Gaseous Hydrocarbons; III. Environmental Factors Affecting the Evolution of the Gaseous Hydrocarbons in Soil; IV. Sampling and Analysis of the Gaseous Hydrocarbons; V. Some Physical and Chemical Properties of the Gaseous Hydrocarbons; VI. Conclusions; References; CHAPTER 5. REACTION OF ANIONS AND CATIONS WITH VARIABLE-CHARGE SOILS; I. Introduction; II. The Development of Charge on Variable-Charge Surfaces; III. Adsorption on Variable-Charge Surfaces; IV. Rates of Adsorption and Desorption

V. Transferring the Variable-Charge Models to SoilsVI. Conclusions; References; CHAPTER 6. KINETICS OF IONIC REACTIONS IN CLAY MINERALS AND SOILS; I. Introduction; II. Methodologies Used in Kinetic Studies; III. Application of Chemical Kinetics to Soil Solutions; IV. Rate-Determining Steps; V. Kinetics Models; VI. Kinetics of Ionic Exchange in Clay Minerals; VII. Kinetics of Ionic Reactions in Heterogeneous Soil Systems; References; CHAPTER 7. ENHANCING NITROGEN FIXATION BY USE OF PESTICIDES: A REVIEW; I. Introduction; II. Rhizobium; III. Free-Living Heterotrophs

IV. Blue-Green Algae in Flooded SoilsV. Resistant Isolates; VI. Choice of Pesticides and Inocula; VII. Limitations; VIII. Summary and Conclusions; References; CHAPTER 8. WEEDS AND WEED MANAGEMENT IN UPLAND RICE; I. Introduction; II. Weed Flora of Upland Rice; III. Ecology of Upland Rice Weeds; IV. Weed Competition; V. Land Preparation and Crop Establishment Techniques; VI. Fertilizer Application and Weed Management; VII. Soil Moisture-Herbicide Relationships in Upland Rice; VIII. Weed Control Methods in Upland Rice; IX. Yield Response of Rice to Herbicides and Herbicide Combinations