292 MASS. EXPERIMENT STATION BULLETIN 171. 



over the amount present in the autumn roots, which might require a little 

 of the sugar in its synthesis; but, on the other hand, the study of the 

 progressive changes in composition of young stalks indicated that they 

 synthesized a part of their sugar before they were of marketable size. 

 Therefore the comparison in this case showed that for every gram of 

 carbohydrate developed in the young stalk at least two grams disappeared 

 from the parent root, one of which must have been used in maintaining 

 the energy of the growing plant, just as the young animal uses a large 

 part of its food in maintaining its body energy. 



The gain in protein during the growth of the crop is of interest in con- 

 nection with the problem of nitrogen fertilization. The transfer of nitro- 

 gen from the autumn root to the growing stalk was apparently accom- 

 pUshed by using only the amino nitrogen of the reserve in the parent 

 crown, and drawing on the soil nitrogen. The increase in nitrogen of 

 summer roots and crop over the amount in the autumn roots is .75 gram, 

 or 7.5 per cent., and is not of sufficient amount to show the necessity of a 

 spring application of nitrogen. 



The gain in ash was confined to calcium oxide and sulfuric acid of the 

 determined constituents, while a part of the variation was undoubtedly 

 due to the very fine sand of the soil which had escaped the cleaning process 

 to which roots and stalks were subjected. 



Calcium oxide and sulfuric acid gained, respectively, .27 gram and 

 .42 gram, or 14 per cent, and 13 per cent. Potassium oxide and magnesium 

 oxide were almost exactly balanced on the two sides, while sodium oxide 

 and phosphoric acid had slight amounts unaccounted for, which may have 

 been due to the difficulties in exact determinations of these constituents 

 in organic substances. 



These comparisons show but little, if any, immediate effect on the spring 

 crop of a spring application of fertihzers. There was a shght apparent 

 absorption of nitrogen, a more marked intake of lime and suKuric acid, 

 perhaps in combination, and no apparent use at this period of potash 

 and phosphoric acid. But as already remarked, these comparisons can be 

 regarded as merely suggestive. 



Amount of Vegetable Matter contained in Ripened Asparagus 



Tops. 

 " The method of asparagus culture now followed by many growers in 

 Massachusetts leaves the tops to die down in the autumn and in the 

 spring works them into the soil by means of a disc harrow. On the experi- 

 ment field a number of the plots have received no annual dressing of 

 manure, and the humus in the soil has been replenished only by the annual 

 growth of tops. 



In the autumn of 1912 Mr. Prescott was requested to determine the 

 weights of the ripened tops on several plots that had received only chemi- 

 cal fertilizers. Mr. Prescott selected one rod of row on each plot, where 



