CROP TREATMENT 227 



Ordinarily, however, after fall sowing there is no 

 further need of treatment until the following spring. 

 The spring treatment is of considerably more im- 

 portance, for when the warmth of spring and early 

 summer begins to make itself felt, a crust forms over 

 many kinds of dry-farm soils. This is especially true 

 where the soil is of the distinctively arid kind and 

 poor in or'ganic matter. Such a crust should be 

 broken early in order to give the young plants a 

 chance to develop freely. This may be accomplished, 

 as above stated, by the use of a disk, corrugated 

 roller, or ordinary smoothing harrow. 



When the young grain is well under way, it may be 

 found to be too thick. If so, the crop may be 

 thinned by going over the field with a good iron- 

 tooth harrow with the teeth so set as to tear out a 

 portion of the plants. This treatment may enable 

 the remaining plants to mature with the limited 

 amount of moisture in the soil. Paradoxically, if 

 the crop seems to be too thin in the spring, harrowing 

 may also be of service. In such a case the teeth 

 should be slanted backwards and the harrowing done 

 simply for the purpose of stirring the soil without 

 injury to the plant, to conserve the moisture stored 

 in the soil and to accelerate the formation of nitrates. 

 The conserved moisture and added fertility will 

 strengthen the growth and diminish the water re- 

 quirements of the plants, and thus yield a larger crop. 

 The iron-tooth harrow is a very useful implement 



