X CONTENTS 



Influence of cultivation upon bacterial action ; Inoculation of 

 soils ; Cultivation for special crops ; Cultivation to prevent washing 

 and gullying of lands ; Bacterial diseases of soils ; Influence of 

 crowding of plants in the seed bed ; Selection of crops ; Inherent 

 and cumulative fertility of soils ; Balanced soil conditions. Pages 

 247-260. 



CHAPTER XIV 



Laboratory Practice. General directions ; Notebook ; Apparatus 

 used in work ; Determination of Hydroscopic moisture of soils ; 

 Determination of the capacity of loose soils to absorb water ; Deter- 

 mination of Capillary water of soils ; Capillary action of water upon 

 soils ; Influence of manure and shallow surface cultivation upon 

 moisture content and temperature of soils ; Weight of soils ; Influ- 

 ence of color upon the temperature of soils ; Rate of movement of air 

 through soils ; Separation of sand, silt and clay ; Sedimentation of 

 clay ; Properties of rocks from which man}' soils are derived ; Form 

 and size of soil particles ; Pulverized rock particles ; Reaction of 

 soils ; Absorption of gases by soils ; Acid insoluble matter of soils ; 

 Acid soluble matter of soils ; Extraction of humus from soils ; Nit- 

 rogen in soils ; Testing for nitrates ; Volatilization of ammonium 

 salts ; Testing for phosphoric acid ; Preparation of acid phosphate ; 

 Solubility of organic nitrogenous compounds in pepsin solution; 

 Preparation of fertilizers ; Testing ashes ; Extracting water soluble 

 materials from a commercial fertilizer ; Influences of continuous 

 cultivation and crop rotation upon the properties of soil ; Sum- 

 mary of results with tests of home soil. Pages 261-274. 



References ; Review Questions. Index, pages 275-283, 284-287. 



