USE OF PHOSPHORUS IN DIFFERENT FORMS 275 



the acid phosphate applied is three times that of the raw rock; 

 and it should be kept in mind that no provision was made to keep 

 the soil supplied with decaying organic matter, although nitrogen 

 and potassium, in commercial form, were applied to all plots alike. 

 If we add together all of the grain and hay produced during the 

 decade following the first year of the experiment, including the 

 oat grain in 1895, the hay in 1896, 1897, 1898, 1899, and 1904, 

 the ear corn in 1900, and the soy beans in 1902, we secure the 

 following totals for the plots designated : 



These figures present in very concise form an economic summary 

 of the Rhode Island experiments with " floats" and acid phosphate, 

 as applied to the more valuable produce of the general farm crops 

 grown during the ten years. The acid phosphate gave slightly 

 poorer results than the raw rock on the unlimed land and 20 per 

 cent better results on the limed land. The value of lime is also 

 strikingly shown. It should be kept in mind, however, that the 

 more abundant growth of clover upon the limed land during the 

 four years, 1896 to 1899, would likely benefit succeeding crops, 

 irrespective of the lime itself. 



The Maine Experiment Station reports two series of experiments 

 with different phosphates, one covering a period of nine years with 

 all tests in triplicate on 2oth-acre plots where equal amounts of 

 phosphorus were compared, and the other for five years (1890 to 

 1894) on 2^-acre plots where equal money values of phosphorus 

 were compared. 



In the nine-year experiments, fertilizers were applied five times 

 in 1886, 1887, 1889, 1893, and 1894. When applied, the amounts 

 per acre were 200 pounds of ammonium sulfate, 100 pounds of 

 potassium chlorid, 360 pounds of fine-ground bone, 300 pounds of 



