THE AFTER-CULTIVATION OF CROPS 167 



open. The efficacy of the soil mulch depends on 

 the thoroughness and frequency of the operation. 

 It is particularly beneficial during long, dry periods. 

 During such times it is not necessary to wait for a 

 rain to compact the soil ; keep the cultivators going, 

 rain or no rain. 



TOOLS FOR AFTER-CULTIVATION 



The main objects of after-cultivation are to de- 

 stroy weeds and to form a soil mulch for the pur- 

 pose of controlling soil moisture. These ends are 

 secured by shallow surface work. It is not neces- 

 sary to go more than two or three inches deep. 

 Deeper work will injure the roots of the crop. 

 Therefore the proper tools for after-cultivation in 

 the garden are the hoe and rake and for field work 

 narrow-toothed harrows and cultivators or horse- 

 hoes which stir the whole surface thoroughly to a 

 moderate depth. These field tools are supplemented 

 in some cases by the hand hoe, but over wide areas 

 of country the hoe never enters the field. 



A light spike-toothed harrow can be used on corn, 

 potatoes, and similar crops, and accomplish the work 

 of cultivation rapidly until they get to be from four 

 to six inches high; after that cultivators which 

 work between the rows should be used. 



A very useful class of tools for destroying weeds 

 in the earlier stages are the so-called " weeders." 

 They somewhat resemble a horse hay rake and have 

 a number of flexible wire teeth which destroy shal- 



