1907.] PUBLIC DOCUMENT— No. 33. 25 



the larger cost of the manure applied to those plots where 

 it is used aloue. 



VI. — Experiment to determine the relative value, as 

 measured by crop production, of a considerable number of 

 phosphates used in quantities to furnish equal phosphoric 

 acid to each plot. The phosphates under comparison are fine 

 ground, — apatite, South Carolina rock and Tennessee rock 

 phosphates ; Florida soft phosphate, basic slag meal, dissolved 

 bone black, raw bone meal, dissolved bone meal, steamed bone 

 meal and acid phosphate. The crop of the past season was 

 mixed hay. The yields on the different phosphates varied 

 relatively little, indicating that the hay crop is dependent in 

 far less degree upon the quantity of available phosphoric 

 acid applied than are the crops belonging to the Cruciferse, 

 such as cabbages and turnips, as shown by previous trials. 



VII. — Soil tests. The past season was the eighteenth 

 during which the soil test reported in detail has continued. 

 The results show the great importance of a supply of nitrogen 

 in highly available form for the production of a satisfactory 

 hay crop. 



VIII. — Experiment in applying manurial substances in 

 rotation for the production of grass. The materials applied 

 in the rotation are: first, barnyard manure; second, wood 

 ashes; and third, a combination of fine-ground bone and 

 potash. The average yield of hay during the past season 

 was at the rate of 4,002 pounds per acre. The average for 

 the fourteen years during which the experiment has con- 

 tinued has been 6,389 pounds. 



IX. — An experiment comparing winter with spring ap- 

 plication of manure on a slope. The crop of the past year 

 was corn, and the results indicate a small loss in fertilizer 

 value, resulting from winter application, but the gain in crop 

 where the manure was applied in spring was not sufficient 

 to repay the extra cost in handling the manure in that manner. 



X. — Experiment in the application of nitrate of soda 

 for rowen. The increase in crop during the past season was 

 considerably more than sufficient to cover the cost of the ap- 

 plication ; but the results in the different years that the ex- 

 periment has continued show a wide variation with the 

 amount of rainfall during the season of growth of the crop. 



