WINTER WHEAT IN WESTERN SOUTH DAKOTA. 5 



necessary to conserve moisture, increases the danger from blowing. 

 It is necessary, as far as possible, to choose some middle course which 

 will involve the least loss of moisture and at the same time minimize 

 this danger. Implements with cutting blades that fine the soil out 

 of all proportion to the value of the work done should not be used. 

 The disk and spring-tooth harrow are preferable, as they tend to 

 bring tlie larger particles and lumps of dirt to the surface and allow 

 the finer particles to reach lower levels of the soil stratum. 



It is important that some method of crop rotation be followed that 

 will supi)ly humus to the soil, as possibly no other factor is so effi- 

 cient in cementing the soil particles together and preventing blowing. 



PREPARATION OF THE SOIL. 



Several methods of preparing the soil for winter wheat have been 

 advocated, such as seeding in small-grain stubble without previous 

 preparation; seeding on corn ground between the standing rows 

 with a 1-horse drill ; seeding on corn ground after preparing with a 

 disk and harrow; seeding on early fall plowing; and seeding on land 

 prepared by summer-fallowing. 



The first two methods are employed to catch and hold the snow 

 and thus prevent winterkilhng. The average snowfall in western 

 South Dakota is rather light and the snow seldom stays on the 

 ground during the entire winter. For this reason the benefit hkely 

 to be derived is not so great as m sections where the snowfall is 

 hea^aer. On the other hand, there is apparently not as much danger 

 from alternate thawing and freezing as in sections where there is 

 more moisture, so that protection is not so necessary. 



Possibly the chief difficulty likely to be encountered in growing 

 this crop on any but summer-tilled land is to conserve sufficient 

 moisture in the soil to germinate the grain and properly maintain 

 its growth until the spring rains begin. The same difficulty also 

 applies to summer fallow not properly cidtivated or when the rainfall 

 is so deficient that no moisture can be stored in the soil. The autumn 

 preci])itation is usually very light and so distributed that it is often 

 insufficient to start the crop. It frequently happens that there is 

 sufficient moisture to germinate the grain but not enough to main- 

 tain its growth, in which case it may be greatly injured or killed by 

 continued drought. On tlie other hand summer tillage is likely to 

 increase the danger from blomng, as the tilth necessary to conserve 

 the moisture leaves the soil in such a condition that it is easUy car- 

 ried away by the \\'ind. 



The lack of experimental data makes it impossible to say just how 

 essential is summer fallow in tlie production of winter wheat. The 

 relative cost, yield, and chances of failure of grain grown on summer 

 fallow and by other methods form a complex problem wliich will prob- 



[Cir. 79.] 



