GROWING GRAIN CROPS IN DRY AREAS 231 



In the autumn when moisture is sufficiently present, 

 and when the soil does not encrust, it may not be neces- 

 sary to use the harrow or the roller on the crop at that 

 season. Oftentimes either implement is so used, but in 

 instances not a few it will be found advantageous to 

 use the harrow when the grain plants begin to show. 

 One objection to autumn harrowing is found in the oblit- 

 eration of the depressions made by the grain drill, which 

 to some extent may increase the hazard to the plants 

 from winter exposure. In the spring there is a decided 

 tendency to encrustation in much of the soil of the west 

 that has been sown to winter wheat. The crust formed 

 must be broken to prevent the escape of moisture, to fur- 

 nish the necessary aeration and to accelerate the forma- 

 tion of nitrates. Usually the best implement to use in 

 order lo accomplish these ends is the harrow. The time 

 and manner of the first harrowing will depend somewhat 

 on the strength of the grain, the character of the soil, and 

 the degree of the encrustation. If the grain plants are 

 small and delicate the harrow used must be light, so as 

 not to bury or tear out the plants. If the soil is loose and 

 not impacted, it may not be necessary to use the harrow. 

 If the soil is very compact and much encrusted, it may be 

 necessary to use a heavy harrow, the teeth being erect and 

 the harrow weighted; and there may be instances in 

 which the disc rightly used or the alfalfa renovator will 

 render better service. Instances are on record in which 

 winter wheat has been severely disced with positive ad- 

 vantage to the crop. The encrustation must be removed 

 if the crop is to make a sufficient growth. This work 

 should be done as early in the spring as it may be done 

 without injury to the land. Proper stirring of the surface 

 at the right time may prevent such encrustation. The 

 subsequent harrowings called for will be largely depend- 

 ent on weather conditions. Some seasons one harrow- 

 ing may suffice. At other times the crop may profit from 



