MANURES FOB SPECIAL CROPS. 277 



you get twice as much corn and stalks to the acre as you would of 

 wheat and straw. In other words, while the wheat cannot find 

 more nitrogen than is necessary to produce 15 bushels of wheat 

 and straw, the corn can find, and does find, take up, and organize, 

 at least twice as much nitrogen as the wheat." 



If these are facts, then the remarks we have made in regard to 

 the value of clover as a fertilizing crop, are applicable in some de- 

 gree to Indian corn. To grow clover and sell it, will in the end 

 impoverish the soil ; to grow clover and feed it out, will enrich the 

 land. And the same will be true of Indian corn. It will gather 

 up nitrogen that the wheat-crop can not appropriate ; and when 

 the corn and stalks are fed out, some 90 per cent of the nitrogen 

 will be left in the manure. 



" You do not think, then," said the Doctor, " that nitrogen is 

 such an important element in manure for corn, as it is in a manure 

 for wheat." 



I have not said that. If we want a large crop of corn, we shall 

 usually need a liberal supply of available nitrogen. But this is 

 because a larger crop of corn means a much larger produce per 

 acre, than a large crop of wheat. Forty bushels of wheat per acre 

 is an unusually large crop with us ; but 80 bushels of shelled corn 

 can be grown in a favorable season, and on rich, well-cultivated 

 land. As the Deacon has said, 30 bushels of corn per acre can be 

 grown as easily as 15 bushels of wheat ; and it is quite probable, in 

 many cases, that a manure containing no nitrogen, might give us 

 a crop of 35 or 40 bushels per acre. In other words, up to a cer- 

 tain point, manures containing mineral, or carbonaceous matter, 

 might frequently, in ordinary agriculture, increase the yield of In- 

 dian corn ; while on similar land, such manures would have little 

 effect on wheat. 



" That is so," said the Deacon, " we all know that plaster fre- 

 quently increases the growth of corn, while it seldom does much 

 good on wheat." 



But, after you have got as large a crop as the land will produce, 

 aided by plaster, ashes, and superphosphate, say 40 bushels of 

 shelled corn per acre, then if you want to raise 70 bushels per acre, 

 you must furnish the soil with manures containing sufficient avail- 

 able nitrogen. 



Some years ago, I made some careful experiments with artificial 

 manures on Indian corn. 

 " Oh, yes," said the Deacon, " they were made on the south lot, 



