1908.] PUBLIC DOCUMENT — No. 33. 39 



of those found in the experiments conducted by the department 

 in various parts of the country to be the most promising, flint 

 and dent varieties both being included, the largest yield was 

 furnished by a variety of dent corn known as Minnesota No. 13 

 and the next largest by the Rustler White dent, a variety largely 

 grown on the college farm in Amherst for the past two years, 

 and obtained originally from a seedsman in Minnesota. Both 

 of these varieties were fairly well ripened, although the cold, 

 rainy spring and early summer months were highly unfavorable 

 to the corn crop in this locality. 



III. — Comparison of Different Potash Salts for Field 

 Crops. (Field G.) 

 The general plan of this experiment is briefly stated in the 

 nineteenth annual report, from which I quote : — 



This experiment is designed to show the ultimate effect upon the soil, 

 as well as the current effect upon the crops, of continuous use of different 

 potash salts. We have under comparison kainit, high-grade sulfate, low- 

 grade sulfate, muriate, nitrate, carbonate and silicate. The field includes 

 forty plots, in five series of eight plots each. Each series includes a no- 

 potash plot, as well as the seven potash salts which have been named. 

 The experiment is therefore carried out each year in quintuplicate. The 

 area of each plot is one-fortieth of an acre. The potash salts under com- 

 parison are used in quantities which will supply annually actual potash at 

 the rate of 165 pounds per acre to each of the plots. All plots are equally 

 manured, and liberally, with materials furnishing nitrogen and phosphoric 

 acid. 



The experiment began in 1898, and the crops in the several 

 years have been as follows : — 



1898. Medium Green soy beans. 



1899. Potatoes. 



1900. Plots 1-8, cabbage; 9-24, Medium Green soy beans; 25-40, 



cow peas. 



1901. 1-8, wheat; 9-40, corn. 



1902. Clover. 



1903. Clover. 



1904. 1-16, cabbage; 17-40, corn. 



1905. Soy beans. 



1906. Potatoes. 



1907. Potatoes. 



