CONTENTS 



PART I. SOILS AND SOIL MANAGEMENT 



Chapter 1. SOIL CLASSIFICATION AND CROP^ADAPTATION 15 



Soils are permanent What farmers should know The" science of the soil How 

 soils are formed Weathering and disintegration Decomposition What is the 

 soil The soil solids The soil fluid Gases of the soil Soil classification-^-Soil 

 surveys -Soils of the United States Classification by texture-yCrop adaptation 

 Summary of soil adaptedness Eastern soils not worn out-^-Soil adaptation of six- 

 teen crops common to Northeastern States Soil adaptation of the leading crops 

 of the North Central Region, South Central and South Atlantic Coast Region, 

 Plains and Mountain Region, Pacific Coast Region Aids to the solution of soil 

 problems. 



Chapter 2. PHYSICAL,"CHEMICAL AND BIOLOGICAL PROPERTIES 33 



Texture of soil Water-holding capacity of soils Water movement in soil Absorp- 

 tion of fertilizers Plasticity and ease of cultivation Texture affects crop adapta- 

 tion Texture affects tillage Structure of the soil Granular structureGranula- 

 tion improved by organic matter Good tilth important Solubility of soil 

 minerals Rate of solubility depends on texture and kind of minerals ^Soil bacteria 

 increase solubility Rapid solubility results in loss of fertility Chemical composi- 

 tion of soils Availability important Elements essential to plants Soil bacteria- 

 Bacteria make plant food available Nitrogen increased by bacteria Bacteria 

 abundant near surface. 



Chapter 3. FERTILITY AND HOW TO: MAINTAIN 44 



Fertility defined Vegetation an index to fertility Drainage reflected in character 

 of vegetation Lime content and acidity related to plants Vegetation and alkali 

 Color of soil related to fertility Maintenance of fertility Fertility lost by plant 

 removal Loss by erosion Preventing soil erosion Farming systems that main- 

 tain fertility Deep plowing advisable Tillage is manure Rotations are helpful 

 Rotations reduce diseases Cover crops prevent loss of fertility Legumes increase 

 soil nitrogen Drainage increases fertility Manure is the best fertilizer Commer- 

 cial fertilizers add plant food only The limiting factor Fertility an economic 

 problem. 



Chapter 4. COMMERCIAL FERTILIZERS 54 



Object and use of commercial fertilizers What are commercial fertilizers Where 

 are fertilizers secured Carriers of nitrogen Phosphorus Potassium Forms of 

 fertilizer materials Relative value of fertilizer ingredients The composition of 

 fertilizers What analyses of fertilizers show JCommercial vs. agricultural value of 

 manures Mechanical condition High-grade vs. low-grade fertilizers Use of 

 fertilizers Value of crop determines rate of fertilization Valuable products 

 justify heavy fertilization Character of fertilizer related to soil What the farmer 

 should know How to determine needs of soil Effect modified by soil and crop 

 Which is the best fertilizer to use Needs of different soils Crop requirements^ 

 Fertilizers for cereals and grasses Legumes require no nitrogen Available forms 

 best for roots Slow-acting fertilizers suited to orchards and small fruits Nitrogen 

 needed for vegetables Fertilizers for cotton Miscellaneous fertilizer facts Effect 

 of fertilizers on proportion of straw to grain Principles governing profitable use of 

 fertilizers When to apply fertilizers Methods of application Purchase of fertili- 

 zers Home mixing of fertilizers. 



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