574 



INDEX OF SUBJECT MATTER 



Fertilizer, how to home mix, 487. 



importance of high grade, 483. 



importance of residues from, 295. 



inspection and control, 480. 



interpretation of guarantee, 481. 



laws of, 480. 



law of diminishing returns, 493. 



low grade and high grade, 479. 



method and time of application of, 

 495. 



purchase of unmixed, 484. 



rational utilization of, 497. 



systems of applying, 496. 



use in United States, 444. 



which should not be mixed, 486. 

 Fertilizer mixtures, those of value, 487. 

 Fertilizer practice, principles of, 471. 



rational system, 497. 

 Fertilizer residues, cause of, 294. 



nature of from different salts, 294. 

 Fillers, use of in fertilizers, 488. 

 Fineness of limestone, data as to impor- 

 tance, 377. 



importance of in liming, 377. 



influence of on decomposition, 378. 

 Fish scrap, composition of, 446. 

 Fixation of nitrogen artificially, 450. 



Bucher method, 453. 



carbide method, 451. 



electric arc method, 452. 



Haber method, 453. 

 Fixation of nitrogen by free-living soil 

 organisms, 430. 



by nodule bacteria, 433. 

 Floats, see rock phosphate, 455. 

 Flocculation, cause of, 131. 



defined, 130. 



relation of to granulation, 144. 

 Flood plain soils, 47. 

 Floors, importance in care of manure, 



521. 

 Flue dust, a source of potash, 465. 

 Food for plants, defined, 8. 

 Forms of water in soil, diagram of, 199. 

 Forms of soil water, 151. 

 Forms of lime to apply, 367. 

 Formulae of fertilizers for different soils 

 and crops, 491. 



examples of, 489. 



theory of, 490. 

 Freezing and thawing, effect on soils, 

 23. 



Frost, importance in soil formation, 23. 

 Fungi and algae, smaller forms in soil, 

 388. 



fixation of nitrogen by, 432. 



injurious to higher plants, 396. 



in soil, number of, 388. 



large forms in soil, 386. 



Germination of seeds, temperature of, 



224. 

 Geological classification of soils, 38. 



resume of, 65. 

 Glacial lakes, origin of, 59. 



soils of, 58. 

 Glacial soils, chemical composition of, 

 57. 



compared with residual, 57, 58. 



fertility of, 57. 



general character, 54. 



importance of, 57. 



origin, 54. 

 Glaciation, American ice sheet, 53. 



effect of, 54. 



influence on agriculture, 58. 



in North America, 54. 

 Glaciers in soil formation, 18. 

 Grading of ground limestone, 377. 

 Grandeau method, nature of, 312. 

 Granite, chemical composition of, 33. 



weathering of, 33. 

 Grass, influence on nitrate accumulation, 

 427. 



influence on nitrification, 422. 

 Granulation of soil, as influenced by 

 lime, 143. 



beneficial effects, 141. 



defined, 139, 141. 



forces producing, 143. 



influence of plowing on, 146. 



influence of tillage on, 144. 



production of, 142. 

 Gravity water, amount soil will hold, 

 177. 



calculation of, 178. 



factors affecting movement, 175. 



importance of study, 178. 

 Green manures, ancient use of, 537. 



as cover crops, 538, 541. 



constituents gained by use of, 539. 



crops for, 545. 



decay of in soil, 541. 



general influence of, 538. 



