56 THE SOIL OF THE FARM. 



facilitate a more equal distribution of the seed than could 

 otherwise take i)lace ; (6) it is used to press into the 

 ground the roots of those plants sown in the preceding 

 autumn w4iich have been detached by frost. 



A spring rolling on a field of winter grain will often, 

 by firming the soil about its roots, save the crop ; and it 

 is equally beneficial in a similar way on grass lands. On 

 light soils the loosening effects of frequent freezing and 

 thawing are more or less avoided by an autumn rolling. 

 Grass land cannot be too heavily rolled ; and on all light 

 lands under tillage the use of the roller is indispensable 

 for closing the pores and preventing the evaporation of 

 moisture. 



But while rolling is of much benefit on light, porous, 

 and lumpy soils, it is injurious on w^et clays, except in 

 dry weather, when they are lumpy after plowing. Soil- 

 ing a stiff soil when wet renders it more difficult of cul- 

 tivation, by pressing the particles still more closely 

 together, and preventing the admission of air. Even 

 light arable lands require the ground to be dry when 

 rolled, if for no other reason than that otherwise the soil 

 will adhere to the roller. Grass land, however, is best 

 rolled in showery weather. 



Using the same power in each case, more land will be 

 rolled in the same time on grass than on a wheat seed-bed; 

 and more on a wheat seed-bed than on rough fallow land. 

 A light one-horse roller, covering about six feet m width, 

 will get over twelve to thirteen acres on grass land, ten 

 acres on a wheat seed-bed, and eight or nine acres on fal- 

 low land, in a working day of ten hours. A two-horse 

 roller should get over twelve to fifteen acres on grass, ten 

 to twelve acres on a wheat seed-bed, and ten acres on 

 fallow. A clod-crusher, drawn by three horses, will ac- 

 complish six to eight acres per day. 



Hoeing. — This operation is proceeded with while the 



