FIELD CROPS 447 



tions, is practiced quite extensively in some of the wheat regions on 

 the Pacific coast and in those western States where dry farming 

 methods are required. To mature profitable crops the land in these 

 sections requires the rainfall of two seasons, and hence wheat is 

 generally grown on land which has had a season of rest and has 

 stored up sufficient moisture to supply the demands of the crop. 

 Cultivation of the summer fallow is practiced to conserve the soil 

 moisture and to increase the store of available plant food which 

 reduces the water requirements of crops. On lands which receive 

 adequate rainfall summer fallow can not be as profitable as the 

 culture of some leguminous crop, which not only adds nitrogen and 

 humus to the soil, but also prevents, or at least largely reduces, 

 leaching. 



Seed and Seeding. The grains of seed wheat besides being all 

 of one variety should also be heavy, plump, and spherical, and free 

 from dirt, weed seeds, and injured or immature kernels. Experi- 

 ments show that it pays to use the fanning mill in grading wheat 

 for seed. Even if the seed be clean, that is, clean with respect to 

 such foreign matter as weed seed and chaff, the elimination of small, 

 shriveled, undeveloped kernels and injured kernels, will warrant 

 its use. Unless the fanning mill or some other means as effective 

 be used to clean the grain that is to be put into the ground, it will 

 be impossible to know how much of that planted will germinate and 

 grow. It will also be impossible to determine when sufficient seed 

 is being sown to produce a one-hundred-per-cent stand. 



The impression seems to have gained very general credence that 

 wheat "runs out" when the same strain is kept for many years on 

 the same farm. No doubt much of the reason for the acceptance of 

 this theory can be found in the experience of very careless farmers 

 who continue year after year to sow poorly selected and poorly 

 cleaned wheat and on poorly prepared land. Such farmers fail 

 to use the fanning mill, so with each succeeding season their seed 

 wheat is made up more and more of light, immature kernels, and 

 inert matter. As the years go by their land loses its fertility, and 

 as the wheat yield grows smaller from this cause, the careless farmer 

 assumes that something constitutional is the matter with his 

 wheat variety. The thinner the land and the poorer the growth of 

 wheat, the greater will be the growth of weeds ; and these not being 

 removed reduce the yield still more. Finally the careless wheat 

 grower may be induced to buy some clean, plump, vigorous seed 

 wheat, and, as might be expected under such circumstances, the yield 

 is noticeably better, particularly when as is often the case the new 

 variety is put in choice ground. It is too often assumed that such 

 improvement has been due to the fact that the new seed came from 

 a distance, when in most cases a similar improvement might have 

 been made by vigorous use of the fanning mill on seed grown close 

 at hand. 



A pure variety i? always to be preferred to a mixture of varie- 

 ties, however slight this may be. Heavy seed promotes stooling and 

 the production of strong plants, and benefits yield and quality of 



