OTHER LEGUMINOUS PLANTS. 113 



grown almost anywhere in the rotation. They will 

 make a good growth on overturned sod, but such 

 land is usually wanted for the production of crops 

 less able to appropriate plant food under adverse con- 

 ditions. When sown in the autumn the winter vetch 

 can with much propriety be sown after a grain crop, 

 and there is ample time between the harvesting of the 

 grain crop and the sowing of the vetches to prepare 

 the seed bed in fine form. The vetches thus sown 

 will be reaped early enough to admit of growing 

 some other crop that same season on the land that 

 produced the vetches. Such a system of rotation is 

 most helpful in cleaning land. When sown early in 

 the spring the crop is also consumed early enough to 

 admit of following it with some kind of catch crop 

 that same season. Winter wheat and winter rye fit 

 nicely into the rotation after spring sown vetches. 



Preparing the Soil. Since vetches are sown 

 sometimes in the spring and sometimes in the 

 autumn, the precise methods of preparing the soil 

 will vary considerably. On fall plowed land the 

 only further preparation necessary is to stir the sur- 

 face soil doeply Enough to furnish a good seed bed. 

 On spring plowed land the aim should be to secure a 

 firm seed bed on the spongy humus soils of the 

 prairie, and to secure a fine pulverization on clay 

 soil that is cloddy. On land plowed in the summer 

 in order to receive seed in the autumn, the aim should 

 be to retain r/Joisture in the land to the greatest ex- 

 tent possible, by the use of the roller and harrow on 

 it after it ha3 been plowed. 



Fertilizers, especially those rich in nitrogen, are 

 less needed by the vetch plant than by plants unable 

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