THE ENEMIES OF ALFALFA 213 



priations and a field agent to supervise the work to be 

 carried out under provisions of law by local officials. 



The injury done by the gophers consists chiefly in 

 throwing up mounds of soil taken from the burrows and 

 these greatly interfere with operating the mowing 

 machine in harvesting. In the alfalfa fields there is also 

 a noticeable thinning out of the plants, by reason of the 

 cutting off of the roots. These root cuttings are stored 

 in the burrows in considerable piles, and are used in cold 

 weather by the gophers for food. It is claimed by some 

 alfalfa growers that this process of thinning out the plants 

 is a benefit rather than an injury to the field, but, says 

 Prof. D. E. Lantz, the official formerly in charge of the 

 Kansas work, 'T have known fields where this thinning 

 has continued until the crop did not half cover the ground 

 at cutting time, and the fields were plowed up for the 

 planting of other crops. The loss from gopher depreda- 

 tions to the alfalfa growers of Kansas during 1901 was 

 probably fully one-tenth of the entire product, and had a 

 money value of at least $500,000." 



According to Professor Lantz, carbon bisulphide and 

 other poisonous gases have frequently been recommended 

 for the destruction of the pocket-gopher, but the great 

 length of the burrowsand their irregularities in depth pre- 

 vent the gases from flowing into every part, and the ani- 

 mals often escape. Trapping, if properly done, is a sure 

 method of killing the gopher; but it is attended with con- 

 siderable labor and is very slow. An excellent trap for 

 general use is the No. O ordinary steel trap. Sink it in 

 loose soil to the level of the runway, nearly conceal it by 

 sprinkling fine earth over it, and leave the hole open. 



