FALL SOWING 215 
dry cold or protracted periods of intense cold, destroy 
the vitality of the seed and young root system. Con- 
tinuous but moderate cold is not ordinarily very 
injurious. The liability to winter-killing is, there- 
fore, very much greater wherever the winters are 
open than in places where the snow covers the ground 
the larger part of the winter. It is also to be kept in 
mind that some varieties are very resistant to winter- 
killing, while others require well-covered winters. 
Fall sowing is preferable wherever the bulk of the 
precipitation comes in winter and spring and where 
the winters are covered for some time with snow and 
the summers are dry. Under such conditions it is 
very important that the crop make use of the mois- 
ture stored in the soil in the early spring. Wherever 
the precipitation comes largely in late spring and 
summer, the arguments in favor of fall sowing are 
not so strong, and in such localities spring sowing is 
often'more desirable than fall sowing. In the Great 
Plains district, therefore, spring sowing is usually 
recommended, though fall-sown crops nearly always, 
even there, yield the larger crops. In the inter- 
mountain states, with wet winters and dry summers, 
fall sowing has almost wholly replaced spring sowing. 
In fact, Farrell reports that upon the Nephi (Utah) 
substation the average of six years shows about 
twenty bushels of wheat from fall-sown seed as against 
about thirteen bushels fromspring-sown seed. Under 
the California climate, with wet winters and a winter 
