14 EXPERIMENT STATION. [Jan. 



Ill this Held nitrate of soda is nsc(l <iii niic jdut in connecliou 

 with the slag meal and high-^rade sulfate of potash at the rate 

 of 200 pounds per acre. This has given an increase, as com- 

 pared with the ])lots to which the slag and potash alone are 

 applied, varying from the insignificant amount of 2G pounds 

 to 3.375 pounds ])er acre in one year. The average increase for 

 the three years was at the rate of 1,479 ])ounds per acre. 



In another section of the field slag meal, high-grade sulfate 

 of potash and nitrate of soda in three different amounts have 

 hecn applied. The increases produced during the past three 

 years have been at the following rates per acre : — 



For the slag, high-grade sulfate of potash and 150 pounds 

 of nitrate of soda per acre. 2,730 to 4,220 pounds, the average 

 being 3,279 pounds. 



For the slag, high-grade sulfate of potash and 200 pounds of 

 nitrate of soda per acre, 2,400 to 2,9C0 pounds, the average 

 being 2,710 pounds. 



For the slag, high-grade sulfate of potash and 250 pounds of 

 nitrate of soda jier acre, 2,080 to 5,470 pounds, the average 

 being 3,747 pounds. 



General OBSERVATioisrs ox Results. 

 The character of the vegetation has been greatly influenced 

 ])y the system of management which has been followed. The 

 most marked effects are the following: — 



(1) The amount of white weed produced has greatly de- 

 creased in all portions of the field which have been top-dressed, 

 and especially on those which have been top-dressed without 

 replowing. The same is true, though to a somewhat less extent, 

 concerning the buttercups and plantain. The dandelions, which 

 come up very early in the s])ring, liefore the grasses and clovers 

 have made much growth, are still relatively abundant. 



(2) On those parts of the field whi(4i have not been to]i- 

 dressed bluets (Houstonia ccevidca) are becoming increasingly 

 abundant, while the yield of hay has become very small, usually 

 varying between 1.000 and 1,500 ]iounds per acre. 



(3) On all ])arts of the field to])-dressed with a ('oiid)iiiation 

 of slag meal and a potash salt, the cloNcrs have become very 



