252 MASS. EXPERIMENT STATION BULLETIN 194. 



My conclusions as to the significance of the results obtained from year 

 to year, as well as many details of the experiment, including the general 

 description of the soil and its preparation, have been presented in the 

 annual reports referred to in the bibliographj'- and in addresses at annual 

 conventions of the Massachusetts Asparagus Growers' Association. It 

 seems advisable to present these conclusions here, and for the sake of 

 completeness I include also conclusions based upon observations on points 

 not considered in the description of the experiment: — 



1. In the year 1910 a late frost considerably reduced the yield of shoots 

 as cut. The cutting season of 1910, moreover, was characterized by low 

 average temperature. For these reasons, the total cut of 1910 was un- 

 doubtedly less than normal; nevertheless, even greater emphasis might 

 well be placed on the effect of rust on a portion of the plots than has been 

 done in the discussion. 



2. The medium amounts of the different fertilizers furnishing the 

 leading plant-food elements applied have furnished the maximum amounts 

 of these elements which prove useful to the crop as indicated by yields 

 produced. 



3. The oak tree which stood near the northeast corner of the experiment 

 field exercised an adverse influence upon the yields of some two or three 

 plots, including those to which sulfates of potash had been applied for 

 comparison with muriate used on plots in other parts of the field. While 

 the plots referred to were not actually shaded by the tree, there can be 

 no doubt that some of its roots extended a short distance into these plots, 

 for it is generally recognized that as a rule the roots of trees which stand 

 in the open extend outward from the trunk in every direction a consider- 

 able distance beyond the tips of the branches. The adverse influence 

 of these roots was clearly shown in the inferior growth of the tops after 

 the close of the cutting season. 



However, muriate of potash appears to be the best form in which to 

 supply that element, this conclusion being based not alone upon the 

 results obtained in the series of experiments under discussion, but in large 

 measure upon results obtained in much longer-continued comparisons of 

 muriate of potash with sulfates under conditions, so far as can be judged, 

 absolutely fair to the comparison of these two forms of potash.^ 



The Humus Content of the Soil in Asparagus Growing. 



In the discussion of the experiment particular attention is called to 

 the fact that the continuous application of manure in this series of experi- 

 ments with asparagus did not appear to exercise a cumulative effect on 

 the humus content of the soil favorable to satisfactory production, and 

 mention is made of the practice of our commercial asparagus growers of 

 allowing the tops grown subsequently to the end of the cutting season to 



I These resiilts have been referred to repeatedly in annual reports, especially those discussing 

 results obtained with asparagus on Field B on the home grounds. For references to details, con- 

 sult indexes of annual reports for 1906-17 (nineteenth to thirtieth). 



