514 



INDEX 



PAGE 



Algae 394 



Alinit 429 



Alkalies, carbonate of, affect struc- 

 ture 118 



Alkali, relation to irrigation 230 



Alkali salts, relation of drainage to 



removal 247 



Alkali soils 307 



Black alkali 309 



Composition 309 



Correction of black alkali 316 



Direct effect on plants 312 



Effect on different crops 313 



Effect on plants 312 



Indirect effect on plants 313 



Reclamation 314 



Reclamation by growing toler- 

 ant plants 318 



Reclamation by leaching 318 



Reclamation by retarding evap- 

 oration 318 



Reclamation by underdrainage.315 



Relation to irrigation 314 



Relation to water content 313 



Rise of alkali 314 



White alkali 309 



Alkali spots 314 



Reclamation 319 



Alluvial soils 47 



Composition of 52, 53 



Alternate, cropping in semi-arid 



regions 196 



Aluminum hydrate, effect on ab- 

 sorption 300 



Amount of water in soil 136 



Amount of water used per irriga- 

 tion 235 



Amendments 348 



Salts of calcium 348 



Use of, part in soil management . 465 



Ammonia, conservation in manure 376 



Formation in farm manures. . . .376 



Ammonification 410 



Ammonium sulfate 326 



Composition of 326 



Effect on acidity of soil 326 



Loss from soil 326 



Manufacture of 326 



Amount of water moved by soil . . . 185 

 Amount of water used in irrigation. 226 



Analysis of marine clay soils 50 



Arid and humid soils 65 



Coastal plain soils 49 



PAGE 



Analysis of common minerals 6 



Cumulose (muck) soils 44 



Dust and loess soils 63 



Earth's crust 4 



Glacial lake soils 51 



Glacial soils 57 



Humus for nitrogen 123 



Mechanical 70 



Residual soils 32 



Soil air 434 



Soil separates 85, 86 



Animal, age of, effect upon ma- 

 nures 373 



Use of, effect on value of ma- 

 nure 374 



Animals and plants, agencies in 



rock decay 28 



Manures produced by different. 368 

 Animal life, effect on structure. . . 118 

 Apparent specific gravity table . . 96 

 Applying water in irrigation, meth- 

 ods 228 



Aqueous rocks 11, 12 



Areas of residual soil, in America . . 31 

 Arid and humid climates, forma- 

 tion of mulches in 198 



Arid and humid soils 64 



Properties 79 



Arid soils, composition of 65 



Organic matter in 125 



Arrangement and porosity 88 



Arrangement of soil particles 88 



Ash of plants, substances found in . 280 

 Atmosphere, as agency of rock 



decay 16 



Composition of 16 



Atmosphere in saturated soil 189 



Atmospheric pressure, effect on 



movement of soil air 440 



See, also, Air. 



Attachments for plow 476 



Available water in field soils 157 



Availability of fertilizers 356 



Availability of phosphate fertiliz- 

 ers 339 



Soil water 141 



Back furrow, meaning of 475 



Bacteria 395 



Ammonification produced by. .410 

 Conditions affecting growth. . . .399 

 Decay and putrefaction pro- 

 duced by 408 



