INDEX 



523 



PAGE 



Minerals, exhaustion of 285 



Groups of 5 



Important soil forming 4 



Matter, decomposition by bac- 

 teria 403 



Nutrients, amounts contained 



in soils 282 



Phosphates, composition . . .335, 336 



Relative abundance of 8 



Table of chemical and physical 



properties 6, 7 



Minimum capillary content and 



wilting 182 



Minimum moisture content 155 



Mixing fertilizers on the farm. . . .346 

 Moisture in soil, as factor in plant 



growth 1 



Affected by manures 221 



As related to soil air 433 



Capacity of soil effect of texture 



and structure 216 



Capillary form 144 



Content and structure 105 



Control of 190 



Critical content 155 



Decreasing loss of 191 



Diffusion of vapor through soil . 190 

 Effect of early spring plowing. .211 



Effect of salt 355 



Effect of structure on move- 

 ment 182 



Effect on porosity 162 



Effect of tent on 214 



Effect on heat conductivity. . . .460 



Effect on soil temperature 461 



Forms and availability 141 



Gravitational form 160 



Hygroscopic form 143 



Increased loss through rainfall . 198 



Maximum content 155 



Means of decreasing 238 



Minimum content 155 



Of soil, adjustment of 170 



Prevention of percolation 191 



Relation to bacteria 399 



/ Should be stored deep 198 



Special treatment to prevent 



evaporation 213 



Used by different crops 185 



Use of hydrostatic form 194 



See Water. 



Modification of structure 104 



Soil temperature means 463 



PAGE 



Modification of structure, texture. 87 



Molds, slime 394 



Moldboard, relation of shape to 



character of soil 472 



, Movement of plant roots in soil . . . 174 



Soil air 439 



Soil air, met hods for modifying . 443 

 Soil moisture, affected by damp- 

 ness 175 



Soil moisture, amount of 185 



Soil moisture, due to texture. . .172 

 Soil moisture supplemented by 



roots 1 74 



Soil moisture, thermal 1S9 



Water, affected by friction . . . .127 



Water affected by solution 173 



Water, affected by structure. . .182 

 Water by soil, lack of data on. . 185 



Water horizontally 172 



Water in soil 165 



Muck 355 



Muck, defined 121 



Ammonia extract, effect on struc- 

 ture 115 



Composition 355 



Crude, effect on structure. . 115, 355 



Organic matter in 125 



Effect on soil moisture 355 



Formation of 41 



Quantity added to soil 355 



Mulches, principles of 199 



Depend on rapid evaporation . . 198 

 Depend upon preventing diffu- 

 sion 189 



Depth of 207 



Effectiveness determined by 



friction 182 



Effect on structure 119 



Example of effect, Cornell Uni- 

 versity 207 



Equalize soil moisture 198 



Implements for creating 207 



Importance of texture 205 



Kinds of 199 



Management of dust 205 



Management of, summarized . . .210 



May be compact soil 205 



Most effective in arid regions. . .204 

 Natural formation in arid and 



humid climates 198 



Relation to irrigation practice. .236 



To prevent wind erosion 496 



When may be formed by roller . 487 



