156 i\IASS. EXPERIMENT STATION BULLETIN 154. 



3. Comparison of different methods of seeding. 



4. A test of a commercial culture for inoculation. 



In addition, we have had under constant observation a 

 number of plots of different ages on which observations as 

 to the gradual displacement of the alfalfa by grasses and 

 clovers have been made. 



1. Grimm compared with Common Alfalfa. 



For a number of years it has been our object to make careful 

 comparisons of the Grimm alfalfa with the common variety 

 from northern-grown seed. Our first trials Avere begun in 1909, 

 but although we obtained what we supposed to be Grimm 

 seed of the very best quality from a grower recommended by 

 the Minnesota Experiment Station, and believed to be abso- 

 lutely reliable, our first experiments were a failure. There were 

 no essential differences either in the appearance or the yield, 

 and the party who furnished the seed later wrote us that a 

 mistake had been made, that the seed sent as Grimm was not 

 true to name. He supplied us, without charge, with seed of 

 the genuine Grimm. This was sown after very careful prepara- 

 tion of the soil on a field where alfalfa had been previously 

 grown in the late summer of 1911. 



The land used in this experiment comprised two plots. 

 Both have received annually for the past twenty-three years 

 an application at the rate of 600 pounds per acre of fine- 

 ground bone meal. One of the two plots has in addition 

 annually received a liberal application of muriate of potash, 

 for the last thirteen years at the rate of 250 pounds per acre; 

 the other plot has annually received the same amount of 

 actual potash, but in the form of high-grade sulphate, and 

 for the last thirteen years at the rate of 250 pounds to the 

 acre. Under both systems of manuring the Grimm alfalfa has 

 given yields considerably larger than those obtained from the 

 common. The results both for 1912 and 1913 are shown in 

 the following table: — 



