Ap-ricultural College, 



massachusetts 

 Agricultural Experiment Station 



BULLETIN No. 212 NOVEMBER, 1922 



A Thirty-Year Fertilizer Test 



By SIDNEY B. HASKELL 



Thirty years ago two soil tests were laid out on the grounds of the Experi- 

 ment Station, in an attempt to determine the "fertilizer needs" of the soil. 

 After thirty years the original problem is still unsolved. It has been shown, how- 

 ever, that fertilizer needs are determined as much by the farming system fol- 

 lowed and the kind of crops grown as they are by the type of soil being farmed. 

 Under a cropping system which removes everything from the soil, severe potash 

 shortage results. Where the crops are fed on the farm, need for fertilizer potash 

 is correspondingly less. Under almost any condition the grass crop responds 

 to fertilizer nitrogen, while the clover crop shows a marked preference for potash 

 and phosphoric acid. Certain fertilizing systems have been shown to be very 

 destructive, while others have been at least moderately efficient in maintaining 

 the crop-producing power of the soil. These facts are among the more impor- 

 tant brought out in the experimental work reported in this bulletin. 



Requests for Bulletins should be addressed to the 



AGRICULTURAL EXPERIMENT STATION 



AMHERST, MASS. 



