May, 1938] 



Experiments With Grass Hay 



Fertilizers Carrying Nitrogen 



Nitrogen was applied to certain series in this test in different nitrogen 

 carriers at the rate of 32 pounds of the element nitrogen per acre. Due 

 allowance was made for the quickness of availability of the different 

 nitrogen carriers, cyanamid being applied about the last week in March, 

 sulphate of ammonia about April 5, and the carriers of nitrate about 

 April 15. Variations from these dates were due to conditions of weather 

 prevailing at the time. 



A summary of the yields of both dry matter and protein is given here, 

 together with the average yield of the check plots and the difference of 

 each treatment from the cheek plot yields. 



Table II. Four-year average of yields of Mathes farm plots after treatment 



with nitrogen carriers. 



The table is arranged in the order of descending yield of dry matter 

 for the different nitrogen carriers. "When the protein is considered, 

 cyanamid should come last in the grouping as the nitrogen recovery from 

 this carrier does not appear to have been quite so high as for the other 

 carriers. 



The differences between the yields of the nitrogen carriers and the 

 check plot series are all significant. Although there are slight differences 

 between the yields of the carriers themselves, there are no significant 

 ones when they are compared one with another. 



From the differences in protein yield it may be inferred that the re- 

 covery of nitrogen from the various carriers was not at the same rate. 

 The order of effectiveness of recovery is the same, of course, as for the 

 proteins. The percentage recovery for each carrier is given in Table IV. 



Complete Fertilizers 



In order to contrast yield responses between nitrogen carriers and 

 complete fertilizers on this soil and to point out the difference which 

 phosphoric acid and potash have made in nitrogen recovery, the series 

 receiving complete fertilizers will now be considered. These are all 

 contrasted with the check-plot yield. 



* Protein is computed in this bulletin by multiplying the nitrogen percent- 

 age by 6.25. 



