CONTENTS 



CHAPTER PAGE 



XXIV, MINNESOTA SOIL INVESTIGATIONS ...... 499 



XXV. CANADIAN FIELD EXPERIMENTS 505 



XXVI. SHORT-TIME POT-CULTURE AND WATER-CULTURE EXPERIMENTS 



IN COMPARISON WITH FIELD RESULTS 513 



PART IV. VARIOUS FERTILITY FACTORS 



XXVII. 



XXVIII. 



XXIX. 



XXX. 



XXXI. 



XXXII. 



XXXIII. 



XXXIV. 



XXXV. 



XXXVI. 



XXXVII. 



XXXVIII. 



XXXIX. 



MANUFACTURED COMMERCIAL FERTILIZERS .... 

 CROP STIMULANTS AND PROTECTIVE AGENTS 



CRITICAL PERIODS IN PLANT LIKE 



FARM MANURE 



LOSSES OF PLANT FOOD FROM PLANTS .... 



LOSSES OF PLANT FOOD FROM SOILS 



FIXATION OF PLANT FOOD BY SOILS 



ANALYZING AND TESTING SOILS 



RELATION OF FERTILITY TO APPEARANCE OF SOILS OR CROPS 



FACTORS IN CROP PRODUCTION 



ESSENTIAL FACTORS OF SUCCESS IN FARMING 



THE VALUE OF LAND 



Two PERIODS IN AGRICULTURAL HISTORY . 



APPENDIX 



SECTION 



1. THE PRODUCTION OF PHOSPHATE ROCK . . . . ' . 



II. MODEL FERTILIZER LAW 



III. COMPOSITION OF ANIMAL AND PLANT PRODUCTS 



IV. STATISTICS OF AGRICULTURAL PRODUCTS 



V. METHODS OF SOIL ANALYSIS 



VI. COMPOSITION OF SOME EUROPEAN SOILS 



VII. AGRICULTURAL COLLEGES AND EXPERIMENT STATIONS IN THE UNITED 

 STATES AND CANADA 



5'7 

 533 

 538 

 S4i 

 549 

 556 

 562 



565 

 572 

 575 

 584 

 586 



590 



595 

 599 

 602 

 605 

 626 

 634 



643 



INDEX 647 



