MASSACHUSETTS ANIMAL INDUSTRY 



149 



It was under these discouraging conditions that the first fertilizer was 

 applied, as a top-dressing, in the early sjiring of 1921. A second, more elab- 

 orate experiment was started in 1922. The fertilizers applied, and the rates 

 at which they were used, were as follows: 



Acid phosphate, 480 and 960 pounds per acre. 



Muriate of potash, 80 and 160 pounds per acre. 



Ground limestone, 2400 pounds per acre. 



Acid phosphate and nuiriate of potasli as above, at 

 the two different rates. 



Space does not permit of extended description of the remarkable effect of 

 these fertilizers. By 1923 many of the plots had developed a dense growth. 

 of white clover. Potash was the most effective of any of the treatments; lime 

 and acid phosphate, used alone or together, were relatively ineffective. Pot- 

 ash and acid phospiiate combined, especially when used in the limed areas, 

 showed a distinct advantage over the potash alone. As time has elapsed, the 

 apparent effectiveness of lime has been increasing; also, but to a less marked 

 degree, has that of tlie acid phosphate. 



Photographic records best portray the remarkable results of this experi- 

 ment. A camera was suspended over a typical area, and in each of three 

 successive years an exposure was made of the same portion of the sod. The 

 upper picture shows the character of the sod as it was before fertilizer was 

 applied; that in the center, taken a year later, shows the changing vegetation 

 as produced by fertilizer; and the lower picture shows the results of 1923, 

 which was definitely a "clover year." The fertilizer here used was the potash 

 and acid phosphate mixture with lime. Similar results were obtained in the 

 experimental plots started in 1922; but here, probably on account of more 

 favorable weather conditions, tlie fertilizer had more rapid effect. 



Effect of Fertilizer on Quality oi Pasturage 



About the middle of June, 1923, animals were barred for a three weeks 

 period from the pasture plots fertilized in 1922. Samples of the three weeks' 

 growth were cut, the product dried, weighed and subjected to chemical anal- 

 ysis. Results are shown in the following table: 



