346 THE BOOK OF CORN 



they often failed. "The corn almost universally refused to 

 conform to nitrogen in fertilizers, and persisted in getting on 

 well without any artificial supply. But it was largely ben- 

 efited by phosphoric acid, and often by potash.' 



These results and concurrent investigations by other sci- 

 entists and by many practical men, led some of the ablest 

 agricultural writers of that time to champion the Atwater 

 theory. Joseph Harris wrote in his book Talks on Ma- 

 nures: "We know less about the manurial requirements of 

 Indian corn than almost any crop. The main question is the 

 nitrogen supply— whether, like other cereals (wheat, barley, 

 oats, grasses, etc), corn has but little power to get nitrogen 

 from natural sources, and requires nitrogenpus fertilizers, or 

 whether, like leguminous plants (clover, beans, peas, etc), corn 

 can gather the nitrogen for itself. That is, whether corn is 

 an exhausting crop like wheat or a renovating crop like 

 clover." 



Summing up his work in 1881, Atwater concluded : "With 

 the mineral fertilizers' alone (phosphoric acid and potash) 

 the corn crop gathered in these experiments some sixty pounds 

 of nitrogen per acre. The important fact, however, is this: 

 The corn plant has in these trials shown itself capable of 

 getting on and bringing fair yields with but relatively small 

 amounts of the less costly mineral fertilizers, even in the 

 worn-out soils of the eastern states. With this help, corn 

 has gathered its nitrogen from natural sources, and holds it 

 readily to be fed out in the farm and returned in the form of 

 manure for other crops. In other words, the experiments 

 thus far imply that corn has somehow or other the power to 

 gather a great deal of nitrogen from soil and air or both; 

 that in this respect, it comes nearer to the legumes than the 

 cereals. That in short, corn can be classed with the 'reno- 

 vating" crops. If this is really so, and this can be settled 

 only by continued experimenting, our great cereal, instead 

 of being simply a consumer of the fertility of our soils, may 

 be used as an agent for its restoration." 



Professor Charles V. Mapes, "without whose interest and 

 enthusiasm, as well as counsel and substantial help, the enter- 

 prise could not have succeeded as it has" (said Atwater in 

 his official report), did much to popularize these results and 

 promote their further verification. In a paper in the sixth 

 annual report of the New Jersey state board of agriculture, 

 1878, Pages 79-167, Mapes emphasizes the exhaustive effect 

 of wheat, barley and other dainty-feeding small grains as 

 compared with renovating crops like clover and corn. He 

 laid stress on the ability of clover, corn and turnips to "for- 

 age" successfully, but the other crops would fail, and sets up 

 the following 



