CULTIVATION 355 



valuable and are most suitable for heavy sod lands and 

 clay soils. The spring- tooth harrow is often used after 

 the disk or cutaway harrows to pulverize and level the land 

 further. In vegetable gardening, one cannot prepare the 

 soil too finely, as it insures uniformity of depth, moisture, 

 and temperature for the seeds. Raking with hand rakes 

 after harrowing is a very expensive practice. A smoothing 

 harrow does the work of a steel garden rake in making the 

 soil very fine. The plank drag is used by many market 

 gardeners to prepare a very fine, smooth surface for small 

 seeds and delicate seedlings. 



Cultivation. --The most important function of cultiva- 

 tion is to preserve soil moisture. Although it is also the 



Fig. 187- Hand cultivation of sugar beets. 



most economical means of destroying weeds, this is really 

 a secondary matter. 



In growing onions, radishes, lettuce, and similar crops, the 

 rows are generally too close to permit the use of horse cul- 

 tivators. Hand cultivators, therefore, are most impor- 

 tant tools in the general intensive garden. 



