242 IRRIGATION PRACTICE 



and become seriously injured. A common experience on 

 dry-farms, where too much seed has been used, is to find a 

 splendid stand of young grain in the spring, and failure 

 at harvest time. Under irrigation, as under dry-farming, 

 the number of plants must be proportional to the proba- 

 ble water supply. If the number of plants is in excess 

 of the probable water supply, the yield will be unsatis- 

 factory. It is always better to sow limited quantities 

 of seed, for by stooling there is an automatic adaptation 

 of the wheat plant to the water in the soil. Experiment 

 has shown that where little seed has been sown, and the 

 water has been sufficient, the harvest is as great as if 

 more seed has been sown. No material change in the 

 acre-yield has occurred even when the seed sown to the 

 acre varied from four to twelve pecks. One bushel or less 

 is probably as satisfactory as larger quantities, except on 

 very rich soils with an abundance of water. 



153. Method of sowing wheat. Wheat and the other 

 small grains should always be planted in rows by some 

 one of the many press drills. This enables the farmer to 

 control the quantity of seed used, and the depth and 

 regularity of planting. Under irrigation, the yield is 

 influenced by the distance between the drill rows. Experi- 

 ments on this subject indicate that the yield is increased 

 when the same quantity of seed to the acre is planted in 

 rows twice as far apart. This may be due to the greater 

 chance, under such conditions, of a large lateral develop- 

 ment of the roots. 



The direction of the drill rows may be of considerable 

 importance. On comparatively level land, the drill rows 

 may help guide the irrigation water from place to place. 

 On rolling land and steep hillsides the drill rows may be 

 run with the contour lines, i. e., across the inclination. 



