46 a EXPERIMENT STATION. [Jan. 



Considerable time has been given to co-operative work with 

 the Association of Official Agricultural Chemists, Mr. L. S. 

 Walker having served the association in the capacity of asso- 

 ciate referee on phosphoric acid for the past season. In this 

 work new methods for the analysis of basic slag phosphate have 

 been studied, also new methods for the determination of avail- 

 able nitrogen and potash in fertilizers. 



{d) Field Experiments with Basic Slag Phosphate. 



This experiment was instituted at the request of the com- 

 mittee on basic slag, which was appointed by the Association 

 of Official Agricultural Chemists for the purpose of determin- 

 ing, through vegetation tests, the efficiency of the phosphoric 

 acid in basic slag phosphate. 



In the fall of 1912, two acres of land, belonging to the Dil- 

 lon farm, situated on the street leading from Amherst to Cush- 

 man, were leased for this experiment. It will be necessary, at 

 first, to exhaust the soil of available phosphoric acid, which will 

 require at least two years. 



(e) Field Experiments ivitli New Mineral Fertilizer and 



Stone Meal. 

 The field which served for this experiment was a part of the 

 two-acre field leased from the Dillon farm and adjoining the 

 land used for the basic slag experiment. The details of the 

 experiment with each crop have been published in Fertilizer 

 Bulletin 'No. 147. 



(/) Incompleted Work. 



A series of pot experiments was begun in the greenhouse 

 during the fall and winter of 1912 to determine the efficiency 

 of stone meal and the new mineral fertilizer as sources of plant 

 food. At the present writing the dry-matter determinations 

 have not l^een made on the crops gro^^^l, and the results will, 

 therefore, be reserved for a future publication. 



Many of the cotton mills in the eastern part of the State 

 produce large quantities of a cotton waste product which shows, 

 upon analysis, a considerable quantity of plant food in connec- 



