INDEX 



Abandoned lands : 



eastern United States, 342, 591 

 Maryland, 140 

 Rothamsted, 403 

 Acid, defined, 20 

 Acid phosphate, 189 

 Acid salts, 23 

 Acidity of soils, 163, 566 

 determination, 627 

 test, 566 



Acids, common, 24 

 Adobe soil, 65 

 African soils, 66 

 Agdell field, Rothamsted, 345 

 Agricultural colleges in the United States 



and Canada, 643 

 established by law, 518 

 Agricultural experiment stations in the 



United States and Canada, 643 

 established by law, 505, 518 

 Agricultural history, two periods, 590 

 Agriculture, permanent systems, 159 

 Aikman, early use of bones, 324 

 Air, composition, 13 

 Alabama, field experiments, 494 



soils, 138 

 Albite, 47 

 Aldehydes, 30 

 Alkali, defined, 20 

 Alkali salt, fertilizer or stimulant, 364, 



393, 402, 479, 533 

 Allyl, 40 

 Aluminum, 44 



American agricultural colleges and experi- 

 ment stations, 643 

 Amids and amido group, 37 

 Ammonification, 195 

 Ammonium sulfate, 525 

 Analysis of animal and plant products, 



157, 602 



Analysis of soils, 626 

 Analyzing, and testing soils, 565, 626 

 Animal and plant products, composition, 



157, 602 

 Animal fats, 35 



Animals destroy organic matter, 199 



Anorthite, 47 



Appearance of soils and crops in relation 



to fertility, 572 

 Arid and semiarid sections, rainfall records, 



580, 582 



Arid soils, 126, 129, 139 

 Arkansas soils, 97 

 Asbestos, 49 

 Ashes, composition, 602 



fertility experiments, 508, 511 

 Asiatic soils, 66, 67 

 Association, National Fertilizer, report on 



raw phosphate, 292 

 Atom, defined, 3 

 Atomic bond, 4 

 Atomic weight, defined, 3 

 Atomic weights, table, 10 

 Available plant food, 107, 314, 366 



Bacteria : 



denitrifying, 439 



nitrifying, 195 



nitrogen-fixing, 207 



nonsymbiotic, or "free-living," 225, 437 

 Barley: 



Canadian experiments, 505 



composition, 603 



Rothamsted experiments, 378 



statistics, 616 



Barn field, Rothamsted, 398 

 Barren soils, 63, 367 

 Base, defined, 20 

 Basic slag phosphate, 192 

 Beans, composition, 417, 603 

 fertility loss, 550 

 Bond, atomic, 4 

 Bone meal, 157, 185 



Bones and other phosphates used in Eu- 

 rope, 324 



Bottom land soils, 62, 120, 138 

 Bradley's soil fertility theories, 300 

 Bran, wheat, composition, 41, 604 

 Breathing pores, 29 

 Broadbalk field, Rothamsted, 363 

 647 



