INDEX 



649 



Earth's crust, 13, 46 



Eastern states soils, 72, 75, 138 



Element system for reporting analyses, 



565. 599 

 Elements in air, ocean, and earth's crust, 



13 



of plant growth, 12 

 the more common, 13 

 transmutation, n 

 English soils, 637 

 Equilibrium in nature, 62 

 Essential elements of plant food, 12 

 European crop yields (see also statistics), 



326 



European soils, 634 

 Experiment stations in the United States 



and Canada, 643 

 established by law, 505, 518 



Factors in crop production, 435, 575 

 Famines, Indian, 334 



Russian, 333 

 Farm manure, composition, 542 



Cambridge University investigation, 205 



Canadian experiments, 508, 511 



dried, 545 



English practice, 324 



Illinois experiments, 201, 206, 459, 473, 

 480 



Japan, human and compost, 594 



Ohio experiments, 204, 256, 442, 448, 



547 



Pennsylvania experiments, 202,423,431 



Rothamsted experiments, 364, 380, 390, 



393. 399, 4oo, 407, 411 

 Fats, 34 

 Felspars, 47 



Fertility theories, 300, 362, 366, 385, 389 

 Fertilizer Association's report on raw 



phosphate, 292 

 Fertilizer law, 599 

 Fertilizers, commercial, 157, 517 

 Fish-scrap fertilizer, 525 

 Fixation of plant food by soils, 562 



of carbon, oxygen, and hydrogen, 29 



of free nitrogen, 207, 225, 437 

 Flax, composition, 603, 604 



sickness, 319 



statistics, 605 

 Florida phosphates, 187, 188, 595 



sand soils, 498 



Formula, chemical, defined, 7 

 France, crop yields (see also statistics), 



327 



soils, 635 



Fruits, composition, 604 

 Functions that are common to different 

 elements, 45 



Gas law, 7 



Georgia, field experiments, 489 



soils, 94 



Germany, crop yields (see also statistics), 

 326 



soils, 634 



Glacial material, 54 

 Glacial soils, 123, 138, 144 

 Glycerin, 40 

 Gneiss, 48 

 Grain farming, 226, 329, 345, 434, 459, 



478, 483 

 Granite, 48 

 Graphite, 26 

 Grass, composition, 603 



digestibility, 199 

 Green manuring, 199, 218 

 Ground limestone and burned lime, 165 

 Growth of plants, 32 



Hall, on soil-fertility theories, 319, 362, 



366, 385 



Hay, composition, 75, 154, 417, 418, 603 

 Hay grown every year, Rothamsted, 391 

 Hay statistics, 605, 624 

 Heat factor in crop production, 576 

 Hellriegel's discovery of nitrogen-fixing 



bacteria, 307 



Hill's view of agriculture, 594 

 History of agriculture, 590 

 Holland, soil, 63 



wheat yield, 614 

 Home of plants, 576 

 Hoos field, Rothamsted, 378 

 Hops, composition, 604 

 Hornblende, 49 



Hunter's soil-fertility theories, 302 

 Hydrate, defined, 28 

 Hydrogen, 28 

 Hydroxid, defined, 17 



Idaho, phosphates, 595 



soils, 102 

 Illinois, field experiments, 283, 453, 476 



pot-culture experiments, 171, 287, 486, 

 487 



soils, 82, 138 

 India, agricultural conditions, 333 



soils, 66 



Indiana soils, 88 



Inoculation for nitrogen fixation, 211 

 Intermountain soils, 127 

 Iowa, field experiments, 488 



soils, 89 



Ireland, soils, 642 

 Iron, 43, 69, 73, 75, 106, 603 

 Iron sulfate as a fertilizer, 158, 505 

 Italian agriculture, 329 



