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 On the Cornell University Farm yields of 50 bushels per acre are often secured.

manner. Such methods are permissible only in a thinly populated country. Some time previous to this some men had noted that in nature the crops grown on a piece of land during a term of years varied, and it is common observation to-day that in the north, hardwood trees, as oaks, will come in where pines have been cut off. Hemlocks do not succeed hemlocks. And even in grass land marked changes occur in the composition of the herbage. During a period of wet years Redtop (Agrostis vulgaris) may assume the ascendancy on a piece of land, and lose it just as quickly when an era of dry years occurs. To secure a rotation of crops, it is essential that crops capable of being grown in a district be known and that there be a market for them. Wheat has been and is the pioneer crop of the northwestern parts of this continent. Climatic conditions are important factors in determining the rotation. In Canada, oats, mangels, clover and timothy may be good crops to include, but they would be of little value for the southern states. Cotton, cowpeas and crab grass would be more likely to grow. It was largely lack of knowledge about crops that prevented progress. Clover and turnips were not grown as field crops in England until about 170 years ago, and even about a hundred years ago, Arthur Young said that probably not more than half the farmers and certainly not over two thirds grew clover, although both turnips and clover were recognized as of value in the sixteenth century, and turnips were used as an article of diet at least as early as 1390. About 1730 Lord Townsend introduced on to his barren estate in Norfolk what has