716 SOILS: PROPERTIES AND MANAGEMENT 



615. Soils associated with dry-farming. - Dry-farming 

 is often closely associated with irrigation, being practiced 

 on the heavier soils where the water-storage capacity is 

 large and where the practice of irrigation is most difficult 

 Successful dry-farming requires an annual rainfall of at 

 least fifteen inches, and twenty inches is much safer as a 

 basis for the practice. A general principle to be observed 

 in dry-farming is that the shorter the soil moisture supply, 

 the lighter should be the rate of seeding. Wheat, for 

 example, may be seeded at the rate of only twenty pounds 



Fig. 82.— Areas of western United States where dry- land farming is or 

 may be practiced. 



