236 



ANNUAL RErORT OF THE 



Off. Doc. 



In general these results corroborate tliose of Table II. The nitro- 

 gen plots show remarkable increases in yield; and the evil effects 

 on color are less evident than in the earlier table. The lower benefit 

 on yield in Plot G is due apparently to the rehitively large yield on 

 this plot the first year, coupled witli a harmful intluence which 

 potash seems to be exerting in this series of experiments. Manure 

 shows itself to be slower in action than nitrogenous commercial 

 fertilizers. The absence of any well defined effect of fertilizers 

 on the crop of the first year is evident here as usual. The lime 

 again shows a very weak infiuence, and the relatively slight benefit 

 that appears is probably due largely to a favorable location in one 

 of the experiments, as explained later. 



In Tables II and III we have had results from various combina 

 tions of fertilizer elements, as well as some from certain materials 

 used singly. Those results being direct from the trees may be 

 considered a close expression of the values thus far of the various 

 combinations used. In many cases, however, we may wish to know 

 which is the more active element in a given combination and ap- 

 proximately what values are to be assigned to each of the elements 

 in it. For example, in Plot 2 of Table II we find a benefit of 78.1 

 per cent, resulting from an application of nitrogen and phosphate. 

 Here the question arises as to how much of this effect was due to 

 nitrogen and how much to phosphate. Any answer to this can 

 be of course only as approximation of the truth and hence the 

 values obtained and shown in the following table are not to be 

 taken too literally. They are the nearest approach to the correct 

 values, however, that we are able to obtain at this time and they 

 were derived in the manner indicated in the footnote to the table. 



TABLE IV 

 Influence of Fertilizer Elements on Yield, Color and Growth * 



Estimated Per Cent, of Benefit 



NITROGEN, in combination — - 49.2% 



NITROGEN, alone, 1 81.1 



Ave. Influence of Nitrogen, 

 PHOSPHATE, in combination, 



PHOSPHATE, alone, 



POTASH, in combination, 



MANURE, alone. 



LIME, alone, - -21.7 



