TABLE OF CONTENTS 



CHAPTER PAGE 



I. Some Conceptions of the Soil and Its Relation to 



Plants . . . . 1 



II. Soil Forming Processes .... .... 16 



III. The Geological Classification of Soils 38 



IV. The Soil Particle and Certain Important Eelations Q6 

 V. The Organic Matter of the Soil 99 



VI. The Colloidal Matter of the Soil 127 



VII. Soil Structure and Its Modification 139 



Vlll. The Porms of Soil Water and Their Characteristics 151 



IX. The Water of the Soil in Its Eelation to Plants . 184 



X. The Control of Soil Moisture 202 



XL Soil Heat 223 



Xll. Soil Air 247 



XIII. The Absorptive Properties ob Soils 263 



XIV. The Soil Solution 275 



XV. The Eemoval of Nutrients from the Soil by Cropping 



and Leaching 289 



XVL Chemical Analysis of Soils 311 



XVII. Alkali Soils 328 



XVIII. Soil Acidity 345 



XIX. Liming the Soil 362 



XX. Soil Organisms, Carbon, Sulfur and Mineral Cycles 384 



XXL Soil Organisms— the Nitrogen Cycle 409 



XXII. Commercial Fertilizer Materials 442 



XXIIL The Principles of Fertilizer Practice 471 



XXIV. Farm Manure 499 



XXV. Green Manure 535 



XXVL The Maintenance of Soil Fertility 552 



Index of Authors 561 



Index of Subject Matter 567 



