IRRIGATION OF CEREALS 241 



will gradually diminish the market value of the softer 

 wheats produced by irrigation. 



Undoubtedly, small grains, especially wheat, as a 

 major crop, will gradually be driven from the irrigated 

 to the non-irrigated lands, although they will always 

 be important crops, since they fit well into rotations. 

 Wherever an irrigation enterprise is begun, it will be 

 found profitable to grow, for some years, extensive crops 

 of the small grains. 



151. Spring vs. fall wheat. Wheat may be considered 

 as a type of the small grains. Formerly, under irrigation 

 practice, spring grains were sown almost entirely. With 

 the advance of dry-farming, which is characterized by fall 

 sowing, irrigated grain is often planted in the fall. The 

 advantage of fall planting is that grain so sown makes 

 better use of the fall and winter precipitation, gets an 

 early start in the spring, and matures earlier. Moreover, 

 less water is required to bring the fall grain to maturity 

 and to a high yield. In harmony with the spirit of econo- 

 mizing irrigation water, the sowing of fall grain should be 

 made a general practice in irrigated sections. 



152. Quantity of wheat to sow. The quantity of 

 seed to sow must be varied with the quantity of irriga- 

 tion water available throughout the season. Under dry- 

 farming, on lands that receive an annual precipitation of 

 12 to 15 inches, twenty-five to thirty pounds of wheat are 

 used to the acre. Under irrigation, with the same annual 

 rainfall, one to three bushels of seed or more are often 

 used. It is not wise to use too much seed, for the numerous 

 plants that result demand a large supply of water, if they 

 are to be brought to maturity; and, if by chance the water 

 supply should be cut off or diminished, the excessive num- 

 ber of plants would speedily exhaust the soil moisture 



