170 



MAINE STATE COLLEGE. 



Dry matter produced in each set of three boxes. 







cc 







OJ 



en 





o 





CD 



ci 





d 



*=■ 



o 



o 



O 



« 



Ph 





grams. 



grams. 



grams. 



15.7 



112.7 



113.3 



17.4 



196.7 



114.6 



69.8 



228. 6 



223.7 



Only soil phosphoric acid 



Water-insoluble phosphoric 

 acid 



Mostly ■water-soluble phos- 

 phoric acid 



grams. 



76.9 



148.6 

 296.3 



grams, grams 

 201.5 39.5 



294.9 

 508.1 



103.3 

 291.0 



grams. 

 154.4 



304.1 

 270.4 



While it may not be desirable to draw definite conclusions from 

 so small an amount of data as is furnished by the above described 

 experiments, there are some points which under the conditions of 

 these experiments the results appear to bring out sharply. 



1st. Different crops showed a decided difference in their powers 

 of obtaining phosphoric acid from crude, finely ground South Caro- 

 lina rock. Wheat, barley, corn, peas and turnips apparently ap- 

 propriated the insoluble phosphoric acid from this source with 

 greater or less ease, while beans and potatoes derived no benefit 

 from it. 



2d. The greatest practical advantage derived from the use of 

 find ground South Carolina rock was with the turnips. With this 

 crop a larger weight of dry matter and also a larger weight of fresh 

 roots was obtained with insoluble phosphoric acid from the finely 

 ground South Carolina rock than with an equal amount of soluble 

 phosphoric acid from acidulated South Carolina rock. 



3d. The indications point to a profitable use of finely ground 

 South Carolina rock as a manure for barley and peas, as well as 

 turnips. 



4th. The acidulated Soute Carolina rock in these experiments 

 apparently depressed the yield of grain with barley, while largely 

 increasing the amount of straw. With wheat, both grain and straw 

 were largely increased and in about the same proportion. 



Maine State College, ] 

 Orono, Me., Nov. 1, 1894. j 



XoTE. These investigations are being continued and -will be kept up, if possi- 

 ble, until the results warrant definite conclusions. Additional data are already 

 obtained and experiments are now in progress. W. H. J. 



