April, 1940] PASTURE TOP-DRESSING IN N. H. 13 



Table 13. — Seven year average yield, Seavey pasture 



because it carries lime, or both. Dry matter produced from super- 

 phosphate is not quite equal to the check-plot yield either in the 

 large triennial application or in the smaller annual one although pro- 

 tein values for both are higher than for the checks. The triennial 

 application of superphosphate has given slightly better yields than 

 the smaller annual applications, while with the potash applications 

 the reverse is true. It is doubtful, however, if the differences are 

 significant, nor would a farmer be justified in making the smaller 

 applications annually, if labor costs were a factor. 



Perhaps the most interesting thing about Table 13 is the rather 

 large increases in both dry matter and protein when superphosphate 

 and potash were applied together, (Plot 10). It is probably the rule, 

 rather than the exception, that when these two materials are applied 

 together, the net increase is greater than when they are applied 

 separately. Certain it is. that in this case, fertilizer balance is very 

 important. 



It should be pointed out also that the increase for superphosphate 

 and potash applied together has made a very substantial showing 

 on Seavey pasture when it is considered that complete fertilizers did 

 not materially increase yields over nitrogen alone. This would ap- 

 ])ear to lead to the conclusion that the heavy grass growth produced 

 l\v nitrogenous fertilizers is definitely inimical to clover growth on 

 this soil, under the conditions of pasturing that prevail. Since the 

 field is not always stocked to its maximum capacity, this is probably 

 true, whereas the same condition would not hold on a pasture which 

 was evenly and closely grazed at all seasons of the j^ear. In Living- 

 ston pasture where clover comes in greater profusion than on Sea- 

 vey, the field is generally cfuite closely grazed and it has not been 

 felt that nitrogen in complete fertilizers inhibited clover growth so 

 that summer pasture yields were seriously reduced. 



Several treatments that have been included on Livingston pasture 

 do not fit into the categories previously discussed. These include 

 annual applications of 0-20-20, 12-4-4, Ammo Phos 11-48-0 and ni- 

 trate of potash. 13-0-44. 



The results from these fertilizers are summarized in Table 14. 



