98 CROP GROWING AND CROP FEEDING 



to corn and small grain, are beginning to realize that they have been losing 

 greatly by the practice, and that permanent pastures and a short rotation in 

 the cultivated land are the things to be sought for. The reason for the desira- 

 bility of the short rotation and the more frequent bringing in of the legumes 

 is obvious if we reflect on the nature of the nitrogen. Most of the nitrogen 

 collected by the legumes is in the form of organic matter in the roots left in 

 the ground. We have shown that green plants do not use nitrogen till in the 

 form of a nitrate. Hence this organic matter must go through the process 

 of decay, and of change in the soil into a nitrate. This is, as we have seen, 

 accomplished through the agency of the nitrifying microbes in the soil. When 

 these have done their work, the nitrogen contained in the clover or pea roots 

 is transformed into a nitrate, and if not then at once used by the plants it is 

 rapidly washed out of the soil. Therefore, if there is a long interval between 

 the crops of legumes, we cannot keep up the supply of nitrogen in this way, 

 and will have to resort to the purchase of complete fertilizers, which a short 

 rotation would render needless. But as organic matter accumulates in the 

 soil, forming humus, it is probable that the complete nitrification may be 

 slower by reason of the increasing acidity which is less favorable to the 

 activity of the nitrifying organisms. Then it is that the use of lime becomes 

 an important adjunct and restores the favorable conditions for nitrification. 

 With a three year rotation, a light dressing of lime once in each alternate 

 round of the rotation (or once in six years), will be found a great aid in the 

 development of the productivity of the soil. Or even a still lighter applica- 

 tion every round of the rotation may prove best. 



A SHORT ROTATION BEST FOR SPECIALIZED FARMING. 



While we are convinced that the greatest evil in farming has been con- 

 tinual cropping with a single crop, and that the only way towards the im- 

 provement of the soil is through a diversified farming, this does not mean that 

 :i farmer should grow a little of everything his climate will produce. He 

 should study his conditions carefully, and find out what is the best money 

 crop for his section and his land, and then should contrive a rotation intended 

 to best promote the success of his money crop. 



The wise farmer will always have a specialty, to the increased production 

 of which he will bend all his energies, while endeavoring in every possible 

 way to reduce the cost of its production by making his subsidiary crops aid in 

 I he defraying of the expenses. His specialty may be cotton, tobacco, wheat, 

 corn or any other particular crop, and his aim should be to grow the money 

 crop more cheaply and at the same time to greater perfection than anyone 



