viii CCNTENTS 



PAQES 



soil constituents, 20 — Weight of soils, 30 — Texture of the soil, 

 32. 



Soil Watrr 32 



Amount of water used by various crops in producing a ton of 

 dry matter, 32 — Mean volume of water held by different soils, 33 

 — Water evaporated by growing plants for one i)art of dry mat- 

 ter produced, 33 — Water needed under arid conditions, 34. 



Plant-food in the Soil 34 



Plant-food in surface soil, with calculations to pounds in an acre, 

 34. 



Alkali Lands 35 



The normal condition of arid lands, 35 — Percentage composition 

 of alkali, 3<) — Quantity of gypsum required to neutralize sodium 

 carbonate, 37. 



Tillage, and Soil Management . 37 



Objects of tillage, 37 — Jordan's rules of fertility, 38. 



CHAPTER III 



Chemical Fkrtilizkks ; and Limk ...... 40-80 



Some of the Sources of Chemical Fertilizers . . . . .41 



Composition of materials used as sources of nitrogen, 41 — Com- 

 position of materials used as sources of phosphoric acid, 41 — 

 Marketed production of phosphate rock in United States, 41 — 

 World's production of phosphate rock, 1005-11)07, 42 — Average 

 composition of Stassfurt potash salts, 42 — Potash salts produced 

 in the United States, 1850 to 1905, 43 — Importation of potash 

 salts, 43 — Pota-ssic materials produced by the aid of electricity, 

 44 — Principal potash material used in United States, 45. 

 Fertilizer Formulas and Guarantrcs ....... 45 



Methods of Computing Value of Fertilizers 47 



Trade-values of plant-food elements in raw materials and chemi- 

 cals, 1010. 47 — Valuation and cost of fertilizers. 48 — Valuation, 

 and agricultural value, 48 — Rule for calculating approximate 

 commercial valuation of mixed fertilizers. 48 — Computing the 

 trade value, 40— IIow to figure the trade value, in greater detail, 

 50. 



Home-Miring of Fertilizers 52 



General advice, 52 — Incompatibles in fertilizer mixtures. 53 — 

 Table for calculating raw materials required per ton by mixtures 

 of given composition, 53. 



