APPENDIX 



(Sunt as a Hilrogrn (gatfjera- 



^JT HE power of the maize plant to assimilate nitrogen from 

 1 1 L the soil, and to some extent from the air in the soil, and 

 \r in the atmosphere, was demonstrated only after many 

 years of experiment and scientific controversy. It can- 

 not now be said that the whole subject is by any means fully 

 understood, but certain principles have come to be generally 

 accepted. And these principles have demonstrated the re- 

 markable power of the corn plant as a restorative crop when 

 grown in proper rotation. 



Professor W. O. Atwater in 1876 inaugurated tests at the 

 Connecticut agricultural exoeriment station to ascertain the 

 truth or falsity of the above principles, which are now so gen- 

 erally accepted. Under his direction similar experiments 

 were conducted by a large number of farmers throughout the 

 country, in co-operation with the American Agriculturist. 

 This was really the inception of scientific work among prac- 

 tical farmers that has since become so popular and had such 

 an important influence. Atwater's work is set forth in great 

 detail in the reports of the Connecticut board of agriculture 

 and the United States department of agriculture. In 1881 he 

 concluded : 



"Of the ingredients of plant food in our soils, the most 

 important, because the most costly, is nitrogen. Leguminous 

 crops, like clover, do somehow or other gather a good sup- 

 ply of nitrogen where cereals, such as wheat, barley, rye and 

 oats, would half starve for lack of it, and this in the face of 

 the fact that leguminous plants contain a great deal of nitro- 

 gen, and cereals relatively little. Hence a heavy nitrogenous 

 manuring may pay well for wheat and be in large part lost 

 on clover." 



This conclusion was directly opposite to the results at 

 Rothamsted, England, for Dr J. B. Lawes had written in 1873 

 to the Massachusetts society for the promotion of agricul- 

 ture that "the best possible manure for wheat, barley, maize, 

 oats, "sugar cane, rice and pasture grass is a mixture of super- 

 phosphate and nitrate of soda. Potash is generally found in 

 sufficient quantities in soils, and an artificial supply is not 

 required." 



But in more than half of Atwater's experiments with corn, 

 and in nearly all with potatoes, the crops were materially 

 aided by potash salts, and without potash in the fertilizer 



