348 THE BOOK OF CORN 



sary. to supply for com on poor land only half the nitrogen it 

 consumed, it would take no more nitrogen to raise one 

 hundred bushels of corn on one acre than thirty-five bushels of 

 wheat. Stewart maintained that the totally inadequate nitrog- 

 enous manure used, resuhing in large crops, conclusively 

 demonstrated that corn is able to get its nitrogen from some 

 occult source, when the crop is sufficiently provided with 

 potash and phosphoric acid. . 



The last article in this controversy v Dr Lawes (ninth 

 report New Jersey board of agriculture, 1882) says : "At the 

 same time, while I think that corn (maize) in common with the 

 other cereal crops is dependent upon a liberal supply of nitric 

 acid in the soil, I must not in saying this be supposed to advo- 

 cate its application artificially. I quite agree with Dr Stewart 

 in thinking that mineral manure alone (phosphoric acid, pot- 

 ash, etc) should be used with the addition of a small quan- 

 tity of nitrogen, so long as they enabled the farmer to grow 

 one hundred bushels of corn, or even a much smaller crop than 

 that, per acre. The only difference between Dr Stewart and 

 myself is this : I think that it is to the soil rather than to the 

 atmosphere that we must look for the supply of nitrogen ; while 

 Dr Stewart's view is that the poverty of his soil does not admit 

 of so large a supply of nitrogen being yielded." 



Dr Lawes concludes : "Corn is a giant among the other 

 grain crops, and for me has a peculiar fascination. I have 

 already called attention to the remarkable advantage which 

 corn possesses over the other cereal grain crops in that it 

 continues growing throughout the summer and ripens in the 

 autumn, but, at the time of writing, I was not so fully im- 

 pressed as I now am with the great value of temperature for 

 the production of nitric acid in the soil. 



"With corn, the most vigorous growth and the most active 

 assimilation of food take place just when nitrification is most 

 at*ive, but when the other cereal crops have done their work. 

 No wonder then that the average yield of corn is much above 

 that of other cereals. At the same time, although corn has 

 access to sources of food in the soil which are not available 

 for other grain crops, still the food itself must come out of 

 the soil." 



CORN AS A EESIORATIVE CROP 



_ Out of the above controversy and by much successful ex- 

 perience among practical farmers extending over the past 

 twenty years, the conclusion is now coming to be generally ac- 

 cepted that in a proper rotation of crops, but with a minimum 

 of manure or fertilizer, the corn crop may be extremely useful 

 in not only maintaining but in restoring the soil's fertility. 



"On the comparatively light and poor soils of New Jer- 

 sey, the land has for many years and in numerous instances, 



