Cultivators and Rollers 89 



It must be borne in mind that in a dry time the less surface 

 exposed the less will be the evaporation. If a large-toothed 

 implement is used to destroy grass and weeds, then it 

 should be followed by a smoother to reduce the ridges 

 and prevent loss of moisture. 



Ridge culture is allowable only when the object is to 

 relieve the soil of moisture on bottom lands where the 

 water comes very near the surface, or for some special 

 crops with which a high degree of warmth is required 

 early in the season; but even then the ridges should be 

 slight. Nothing could be better calculated to dry out a 

 potato-field or a corn-field than throwing the ground up 

 on high ridges, leaving a large surface exposed to the 

 action of sun and wind. In fruit-plantations in a proper 

 state of tillage, unless very heavy clay, a small-toothed 

 or even spike-toothed cultivator will be found sufficient 

 to maintain the surface mulch. 



The roller, in its relation to soil-moisture. 



The roller is an implement whose value depends largely 

 on special conditions. There is no tool that requires more 

 judgment as to proper use. On light, loose, sandy or 

 gravelly soils, where every effort must be made to solidify 

 and pack the particles closely together, the roller may be 

 used repeatedly. The difficulty with such soils is that the 

 spaces between the grains are so large that the water is 

 permitted to pass through freely, and is lost by percola- 

 tion. The capillary openings are so large that there is 

 very feeble rise of the water to take the place of that used 

 by plants and lost by evaporation. The roller lessens the 

 size of these pores in solidifying the soil, and the capillary 

 force is then strong enough to draw the water to the sur- 

 face. If, now, the soil is left in this condition, it has been 



