16 EXPERIMENT STATION. [Jan. 



a much greater amount of fruit. It will be noted that both 

 have annually received equal amounts of bone meal, and, since 

 muriate of potash contains practicallv double the amount of 

 actual potash contained in the low-grade sulfate, and is applied 

 in one-half the quantity of the latter, it will be seen that both 

 have received annually practically equal amounts of actual 

 potash (at the rate of 100 pounds per acre). These two plots, 

 therefore, have received annually applications supplying equal 

 amounts of the three most essential elements of plant food, — 

 nitrogen, phosphoric acid and potash. There is, however, one 

 important difference in the applications made to the two plots. 

 The low-grade sulfate of j^otash contains a large amount of 

 magnesia ; muriate does not supply this element. Whether the 

 superior growth and fruitfulness of the trees on plot 5 is due 

 to the magnesia supplied we cannot, unfortunately, feel cer- 

 tain. We know, indeed, that mag-nesia is an essential element 

 of plant food. It is, however, an element which ordinarily 

 appears to be supplied in sufficient quantities from natural 

 sources. It is of course possible that there may be a natural 

 difference in the soil of the two plots, although this is not 

 believed to have been the case ; or that the sulphuric acid com- 

 bination with potash (sulfate) is better suited to the trees than 

 the hydrocholoric acid of the muriate. 



Experiments upon a larger scale to test the questions raised 

 by the result of this experiment are now in progress. 



This experiment shows most decisively that apple trees must 

 1)0 fed to grow well and bear well. The inferior results ob- 

 tained on plot 3, which has been unmanured throughout the 

 entire period of the experiments, strikingly establishes this 

 j)oint. 



The manure used in this experiment is undoubtedly furnish- 

 ing too large a proportion of nitrogen. The growth of the trees 

 is rank; the foliage is heavy; the fruit is overgrown, coarse 

 and inferior in color. In this particular experiment the com- 

 bination of bone meal with low-grade sulfate of potash has 

 produced results which, on the whole, must be regarded as the 

 most satisfactory. 



