24 Experiment Station Bulletin 363 



ing to plan. The top-dressing scheme invoh^es variations in the level of 

 potash with uniform nitrogen and phosphoric acid. One harvest only 

 was secured in 1944. The stand of clover on this field was not maintained 

 and there was very little clover in evidence in 1944. This was likely due 

 to severe winterkilling in the later winter of 1943-44. 



It is noteworthy that 100 pounds of muriate of potash is as effective 

 as 10 tons manure in increasing yields and that 200 pounds equal the 

 effect of 20 tons. Three hundred pounds of potash gave no increase over 

 the 200-pound application. The results for using small amounts of boron 

 are encouraging and the study of the value of this substance in hay pro- 

 duction should be continued. 



On another section of this field, plots 47 to 80, hay yields are being 

 studied under a system of annual top-dressing. The seeding was made 

 in 1937, and hay has been harvested each year since. Yields varied from 

 1,900 to 6,600 pounds per acre in 1944. 



The data offer evidence as to how hay yields can be maintained at 

 a relatively high level over a period of years. As has been explained in 

 previous reports some of the series of plots have been top-dressed annual- 

 ly since 1937 at the same rate and without interruption. In the spring of 

 1942, treatments on certain other series were modified and since that time 

 have been treated each spring with fertilizers equivalent to certain of the 

 other treatments. Therefore, there are now three pairs of identical treat- 

 ments since 1942. 



For example, K (old) and K each received 125 pounds of muriate of 

 potash per acre annually. Prior to 1942, the plots designated K had re- 

 ceived no potash. On the basis of the three-year average the K plots 

 have yielded 736 pounds less hay than the K (old) plots. 



The same differences apply to the PK and 0-20-20 plots since the 

 treatment beginning in 1942 has been identical, but the PK plots, which 

 had a longer background of receiving super^'and potash, yielded as an 

 average 1,887 pounds more hay than the 0-20-20. 



A similar comparison may be made between the NPK treatment 

 which has been applied since 1937 and the 8-16-16 which has been in op- 

 eration only since 1942. The NPK yield averages 2040 pounds higher. 

 The inference from these three comparisons is obvious, to keep hay 

 yields at a high level an annual top-dressing system should be practiced. 



The efficacy of potash in favorablx' influencing yields is shown by 

 the difference between K (old) and the check or untreated plots, a dif- 

 ference of 1165 pounds. Another comparison is obtained between the 

 8-16-16 -f K series and the 8-16-16 plots in which there is a difference 

 of 971 pounds. This difference was more striking in 1944 than in pre- 

 vious year, 1944 yields showing a 2034-pound greater yield on the com- 

 plete fertilizer \\ ith extra potash as against complete fertilizer alone. 



F. S. Prince, P. T. Blood, G. P. Percival 



Experiments with Small Grains in Northern New Hampshire 



This experiment was undertaken to determine the highest yielding 

 varieties of small grains for Northern New Hampshire, w here the cli- 



