WORKING THE SOIL 155 



field is conserving energy that may be applied to bet- 

 ter purposes after the day's work in the field is fin- 

 ished. 



KNIFE-EDGE PULVERIZERS 



A knife-edge weeder makes the best dust mulch pul- 

 verizer for orchard work or when preparing a seed- 

 bed for grain. These implements are sold under dif- 

 ferent names. It requires a stretch of imagination to 

 attach the word "harrow" to these knife-edge weed- 

 ers. There is a central bar which is usually a hardwood 

 plank. The knives are bolted to the underside of the 

 plank and sloped backward and* outward from the 

 center to the right and left, so that the knife-edges 

 stand at an angle of about 45 to the line of draught. 

 This angle is just about sufficient to let tough weeds 

 slip off the edges instead of dragging along. If the 

 knives are sharp, they will cut tender weeds, but the 

 tough ones must be disposed of to prevent choking. 

 The proper use of the knife-edge weeder prevents 

 weeds from growing, but in farm practice, sometimes 

 rainy weather prevents the use of such a tool until the 

 weeds are well established. As a moisture retainer, 

 these knife-edge weeders are superior to almost any 

 other implement. They are made in widths of from 

 eight to twenty feet. The wide ones are jointed in the 

 middle to fit uneven ground. 



CLOD CRUSHER 



The farm land drag, float, or clod crusher is useful 

 under certain conditions on low spots that do not drain 

 properly. Such land must be plowed when the main 

 portion of the field is in proper condition, and the re- 

 sult often is that the low spots are so wet that the 



