38 CROPPING SYSTEMS 



Lime. A very large proportion of the land in the eastern half 

 of the United States is benefited by lime. This is especially true of 

 the land originally in heavy timber, outside the distinct limestone 

 regions. Usually, from 1000 to 2000 pounds per acre of burnt lime 

 is applied, or its equivalent in hydrated or ground limestone. The 

 equivalents are : 



Burnt lime 56 pounds 



Hydrated lime 74 pounds 



Ground limestone 100 pounds 



The lime is best applied with a lime spreader, but is often spread 

 with a shovel. Lime may be applied at any time when there is no 

 crop on the land. 



When Fertilizers Are Applied. Fertilizers are more com- 

 monly applied to wheat, potatoes and grass than to other common 

 farm crops. Ordinarily, oats, corn, and clover do not respond suf- 

 ficiently to fertilizers to pay for direct applications to these crops. 

 Corn, potatoes, and grass make relatively better use of manure than 

 other crops, and the barnyard manure is most profitably applied to 

 these crops. 



In a typical rotation consisting of corn, oats, wheat, clover, and 

 timothy for one or more years, the common practice is to apply 

 fertilizer to the wheat, and again fertilizer to the grass, after the 

 first year. If manure is available, the best place to put the manure 

 is on the grass, the last year before breaking up. The grass is thus 

 benefited one year, and the corn crop following is benefited about as 

 much as though the manure were applied directly to this crop. 



On wheat, the fertilizer is usually applied at the time wheat is 

 seeded, by means of a wheat drill with fertilizer attachment. On 

 grass, the fertilizer is applied with the same tool, or a regular fer- 

 tilizer spreader, about two weeks after spring growth starts. 



BARNYARD MANURE 



Amount Made by Animals and Value. Professor Roberts, of 

 Cornell, compiled data showing the amount and value of manure 

 made by various farm animals. He estimated the value by charging 

 the price paid for the nitrogen, phosphate, and potash, in commer- 

 cial fertilizers. However, in addition to the minerals, manure adds 



