CONTENTS. 



CHAPTER PAGE 



I. Historical and Introductory . - . . i 



II. Soil Conditions affecting Plant Growth - - 30 



III. (^The Composition of the Soil ^ - - - - 92 



IV. The Colloidal Properties of Soil - - - 148 

 V. The Carbon and Nitrogen Cycles in the Soil - 175 



VI. The Biological Conditions in the Soil - - 218 



VII. The Micro-Organic Population of the Soil and 



ITS Relation to the Growth of Plants - 250 



VIIL^The Soil in Relation to Plant Growth /- - 301 



IXi,^SOIir'ANALYSIs'"AND~ITS INTERPRETATION^ - - 322 



APPENDICES. 



I. The Methods of Soil Analysis . - - - 347 



II. Amounts of Various Substances Absorbed from 

 THE Soil by the Common Agricultural Crops 



of England 357 



III. A Selected Bibliography of Papers on Soil Con- 

 ditions AND Plant Growth ... - 359 



Author Index 3^7 



Subject Index 395 



