ALFALFA 189 



harm done, therefore, by floods in each case can 

 only be known by waiting to see the results. These 

 summer floods always harm the crops temporarily, 

 and in many instance kill them outright. Occa- 

 sional periods of overflow should not prevent the 

 sowing of alfalfa on such lands, since on these it 

 is usually not difficult to start a new crop, but the 

 seed should not be sown on such lands when over- 

 flow occurs at such a season. When it occurs in 

 cool weather and quickly subsides, it may be pos- 

 sible to grow paying crops of alfalfa. 



In some areas grasshoppers are a real scourge in 

 alfalfa fields. Because of the shade provided by the 

 ground and the influence which this exerts in soften- 

 ing it, they are encouraged to deposit their eggs 

 and remain so as to prove a source of trouble the 

 following year. It has been found that through 

 disking of the land both ways after sharp frosts have 

 come is greatly effective in destroying the grass- 

 hopper eggs deposited in the soil. They are thus 

 exposed to the action of the subsequent frosts and so 

 perish. The disking has also tended to stimulate 

 growth in the crop the following year. The eggs 

 will not, of course, be all destroyed by such disking, 

 but so large a percentage will, that the crop should 

 be practically protected from serious injury, unless 

 when grasshoppers come from elsewhere. 



It would seem correct to say that gophers do more 

 injury to alfalfa fields in certain areas of the West 

 than comes to them from all other sources com- 

 bined. They not only destroy the plants by feeding 

 upon them, but they fill the soil with mounds, which 



