138 HATCH EXPP:RIMENT STATION. [Jan. 



Our experiments indicate that the cabbage i.s one of those 

 crops most closely dependent upon the supply of available 

 phosphoric acid, and yet this crop gives us a good return 

 upon phosphates ordinarily regarded as very slowly avail- 

 able. The opinion in general held concerning the necessity 

 for acidulated phosi)liates may need modification. We have 

 not, it is true, raised on the South Carolina rock or the raw 

 bone crops of the highest rank, as measiu'ed by the number 

 and W'cight of hard heads. The total yields are excellent, 

 and the weights of hard heads in a more normal season would 

 without doubt have been nmch higher. It ajipears reason- 

 able to believe that on soils of the character of this field the 

 farmer may safely depend for a considerable portion at least 

 of the phosphoric acid needed by his crops upon the chea})er 

 natural phosphates, such as finely ground South Carolina 

 rock and finely ground bone, while phosphatic slag also 

 promises to prove a most useful fertilizer upon soil of this 

 character. 



VI. — Soil Tests. 



Two soil tests, both u^jon our own grounds and both in 

 continuation of previous work upon the same fields, have 

 been carried out during the past season. Fertilizers have 

 been applied in accordance with the co-operative plan for 

 soil tests, with one or two small exceptions. Lime and 

 plaster have been applied to the plots calling for these fer- 

 tilizers in double the usual soil test amounts. Each plot 

 annually receives an application of the same kind or kinds 

 of fertilizers. Such experiments are not adapted to securing 

 the production of heavy crops, but rather to throwing light 

 ui)()n the general question as to the particular plant food 

 re(juirements of difterent crops. By study of the results, 

 the eftects of the difterent leading elements of plant food on 

 the several crops can be determined with much accuracy. 



Every fertilizer used, whether a])plied by itself or in con- 

 nection with one or both of the other fertilizer materials, is 

 always applied in the same quantities. Both fertilizers and 

 manure (where the latter is introduced for })urposes of com- 

 parison) are always a})plicd broadcast after plowing, and 



