USE OF PHOSPHORUS IN DIFFERENT FORMS 281 



years of the experiment, and we have the following statement from 

 the Massachusetts Report for 1896, page 190, concerning the earlier 

 history of this field: 



"Previous to 1887 it was used as a meadow, which was well worn out at that 

 time, yielding but a scanty crop of English hay. During the autumn of 1887 

 the sod was turned under and left in that state over winter. It was decided 

 to prepare the field for special experiments with phosphates by systematic ex- 

 haustion of its inherent resources of plant food. For this reason no manurial 

 matter of any description was applied during the years 1887, 1888, and 1889. 



"The soil, a fair sandy loam, was carefully prepared every year by plowing 

 during the fall and in the spring, to improve its mechanical condition ; during 

 the same period a crop was raised every year." 



A second series of experiments with different phosphates was 

 begun by the Massachusetts Station in 1897, upon thirteen plots 

 of land that had all received 600 pounds of bone meal per acre in 

 1896. In this series equal amounts of phosphorus are being applied 

 in ten different phosphates. The results thus far reported are 

 variable and inconclusive. In some cases soluble phosphates have 

 produced the best yields, especially upon garden vegetables, while 

 in some other cases the raw phosphates have given better results. 

 Of course the 600 pounds of bone meal applied to the entire field 

 in 1896 greatly reduced the need for phosphorus for some years. 

 The published data are given in Table 49. (See Massachusetts 

 Reports 1898 to 1907.) 



In the report for 1903, Professor Brooks makes the following 

 comments concerning the cabbage crops: 



"Apatite and soft Florida phosphate are the least effective among the phos- 

 phates employed. 



"South Carolina rock gives a surprisingly good return, being exceeded in 

 yield of hard heads by only one plot, the one receiving dissolved bone, 

 while in total yield it is materially exceeded by but few. 



"The phosphatic slag ranks among the best of the phosphates." 



Professor Brooks also makes the following general statements 

 concerning these phosphate experiments: 



"In estimating the significance of the results upon this field, it is important 

 to keep in mind the facts as regards the character of the soil. It is what would 

 be called a strong and moderately heavy loam, and has great capacity to retain 

 moisture. The relatively insoluble phosphates are known to give better results 

 on soils of this character than on those which are lighter and drier." 



