j ( ; ( ; A gricultura I Che mistry. 



acid present. When grain crops tend to mature early, with well 

 defined, well developed, plump and heavy kernels, there will be 

 little doubt that the soil contains a good supply of available 

 phosphoric acid. Potash fertilizers are, generally speaking, of 

 .special lieiidit in the case of leafy plants like tobacco, cabbage. 

 beets, clover and potatoes. While some help may be had from the 

 above suggestions, nevertheless definite methods of procedure 

 have been proposed by several investigators, and will be dis- 

 cussed briefly. 



Ville system. ' ; The system which has perhaps received the 

 most attention, doubtless largely because one of the first pre- 

 sented, and in a very attractive manner, is the one advocated by 

 the celebrated French scientist, George Ville. This system, while 

 not to be depended upon absolutely, suggests lines of practice 

 which, under proper restrictions, may be of very great service. 

 In brief, this method assumes that plants may be, so far as their 

 fertilization is concerned, divided into three distinct groups. 

 One group is specifically benefited by nitrogenous fertilization, 

 the second by phosphatic, and the third- by potassic. That is, 

 in each class or group, one element more than any other rules 

 or dominates the growth of that group, and hence each particular 

 element should be applied in excess to the class of plants for 

 vvhich it is a dominant ^agrediejat^In this system it is asserted 

 that nitrogen is the dominant ingredient^JIpjp wheat, rye, 

 barley, meadow grass and beet crops. Phosphoric acid is 

 dominant fertilizer ingredient for turnips, Swedes, Indian coi 

 (maize), sorghum, and sugar cane; and potash is the domin* 

 or ruling element for peas, beans, clover, vetches, flax, and pol 

 toes. It must not be understood that this system advocates onl] 

 single elements, for the others are quite as important up to i 

 certain point, beyond which they do not exercise a controlling 

 influence in the manures for the crops of the three classes. This 

 special or dominating element is used in greater proportion tl 

 the others, and if soils are in a high state of cultivation, or hi 



