IO6 THE FIRST BOOK OF FARMING 



ROLLING 



The objects of rolling are: 



To compress the surface soil so that the harrow 

 will do its work more efficiently, also to break clods 

 or lumps that may have resisted the action of the 

 harrow. 



To smooth the surface of the soil for an even 

 distribution of small seeds, and to firm the soil 

 around such seeds after they are planted so that 

 they will keep moist and sprout readily. 



To give compactness to soils that are light and 

 loose and thus enable them to hold moisture and 

 plant food better. 



To press into the ground the roots of plants 

 partly dislodged by the frost. 



To remove the conditions favorable to the de- 

 velopment of many kinds of insects. 



To sink surface stones so that they will not in- 

 terfere with harvesting the crop. 



Light porous soils may be rolled at any time, but 

 clay soils can be rolled to advantage only when 

 they are stiff and cloddy. 



Spring-sown grain is often rolled as soon as 

 sown. This is all right in ordinary spring weather, 

 but if showers are frequent and the soil is quite 

 moist the rolling should be omitted till after the 

 grain is up. The same practice will apply to au- 

 tumn-sown grain also. If the soil is dry the rolling 

 helps it to pump water up to the seeds. But if it 

 is moist and showers are frequent the combined 



