296 



STATE COLLEGE. 



Experiment No. 3. 

 An acre of land adjoining the nitrogen experiment was devoted to 

 an experiment for growing beans with different forms of phosphoric 

 acid, known as soluble, reverted or precipitated and insoluble phos- 

 phoric acid. Combined with this experiment is one in regard to the 

 quantity of phosphoric acid that can be applied with profitable 

 results. The land used for the experiment was of the same charac- 

 ter as that used for the nitrogen experiment, and had received the 

 same treatment in previous 3'ears. It was divided into plots of the 

 same dimensions as the plots for the preceding experiment and in 

 ever}- way treated the same except in the matter of fertilization. 

 Plots from 1-18 received a basal mixture of 10 lbs. sulphate of 

 ammonia and 10 lbs. of muriate of potash. To this mixture was 

 added the fertilizer containing the different forms and quantities of 

 phosphoric acid for the different plots ; dissolved bone black furnish- 

 ing soluble phosphoric acid, dissolved bone black with chalk furnishing 

 precipitated phosphoric acid, and bone black furnishing insoluble 

 phosphoric acid. The precipitated phosphoric acid was obtained by 

 mixing together equal parts of dissolved bone black and chalk, then 

 wetting down the mixture and allowing it to stand two weeks before 

 using. At the end of that time it showed only a slight trace of 

 soluble phosphoric acid. The table below shows the results of the 

 experiment. Groups I a, II a, and III a, are duplicates of Groups 

 I, II and III. 



No. OF Plot. 



Soluble pbos-( 



pboric acid. . 



Group I. ( 



Precipitated i 



phos. acid. . 



Group II. I 



Insoluble ( 



phos. acid. . 



Group 111. I 



Soluble plios- ( 



phoric acid. . 



Group I a. i 



Precipitated ( 



phos. acid. . 



Group II a. ( 



Insoluble i 



phos. acid. ■ 



Group III (I. I 



Name of Fertilizers. 



No manure 



Basal mi.\ture, 15 lbs. dissolved bone black 



'• 10 " " 



II 5 << <t 



Basal mi.xt., 13 lbs. dis. bone black, 15 lbs. chalk 

 " 10 " 10 " 



" o " 5 " 



Basal mixture, 15 lbs. bone black 



" 10 " 



" 5 " 



Basal mixture, 15 lbs. dissolved bone black 



X 10 " " 



" 5 " " 



Basal mixt., 15 lbs. dis. bone black, 15 lbs. chalk 

 " 10 " 10 " 



"5 " 5 " 



Basal mixture, 15 lbs. bone black 



" 10 " 



" 6 " 



No manure. . . 



CD.-:; . 



en [.. O 



-3 1= fc. 

 g CO 3 



h -^ a 



5 o-g 



100 



60 



60 



120 



60 



90 



50 



80 



60 



80 



100 



100 



110 



20 



60 



60 

 40 

 50 



