883 



As in ISOO, siiinplos of the ijotatoes from the differently manured 

 plats were taken loranalysis. Tlic indications fioin the analyses in 1S90 

 were that manuring" nuiterially att'ected the composition of the potat(>, 

 decreasing the starch, and that in this respect the effect of sulphate of 

 potash was less than that of eitlier muriate of potash or kainit. 



Tlio ;iualyses in ISDl show that while on the average there was less dry matter 

 ill saiiii>les tVoiu plats treaterl with iiiamiros, those froiii jilats whieh niccived siil- 

 l>liate ol'potash contained more dry matter than tlie samples from the nnfertiiized 

 jdats, while with one exception those from mnriale of potash and kainit contained 

 less. The samples from the fertilized plats also contained less nitrogen and more 

 ash than those from the untreated plats; as a rule the ash was the highest and the 

 nitrogen the lowest on samples from the kainit plats. With one exception, the 

 liighest nitrogen in samples from fertilized jdais was secured from those treated 

 with sulpiiate of potash. 



In resjieit to nitrogen as alhumiuoids, it is shown that while on the average 

 nearly "lO per cent was in this form and the greatest amount was contained in the 

 potatoes from the unfertilized jilats, it was proportionately greater upon the ferti- 

 lized [ilats. 



Samples from the ditlVreut plats in each experiment were also cooked under uni- 

 form conditions, and, with the exception of tliose grown by Mr. Gardiner, tins results 

 were deci<le(lly in fav()r of the snl]>hate of potash. These results simply contirm 

 those secured in 1800, in showing that while on the whole manures have a tendency 

 to decrease the dry matter of the potato, in using those whieh contain potash in the 

 form of sulphate the amount of dry matter of the potato is not materially different 

 from that scoured when no manures are used. 



Field expp:riment« with fertilizers on sweet potatoes, 

 E. B. VooRHEi^s, M. A. (pp. 17-2-1). — It is explained that the com- 

 mon practice in growing* sweet potatoes in Xew Jersey is to scatter 

 broadcast from S to 10 tons per acre of manure, chiefly horse manure, 

 and to apply an equal amount in the hill or row at the time of setting 

 the plants. The object of the experiment was to ascertain whether 

 satisfactory crops can be raised without l)arnyard manure, and to com- 

 pare the eflects of commercial fertilizers, barnyard manure, and a mix- 

 ture of the two. The general plan was identical with that followed in 

 the experiments with white potatoes reported above, except that the 

 ]»lats were 5 by 130 feet in one case and 10 by 218 feet in another. 

 The exi)eriments were made on two farms. In experiment Xo. 1 the 

 l)lants were set May 14 in rows 2.5 feet apart, being 18 inches apart 

 in the row. In experiment No. 2 the plants were set 2.5 feet apart 

 each way, May 22-20, but many died and had to be re]tlaced in June. 

 The yields and the tinancial lesults are tabulated for both trials. In 

 the case of experiment No. 2 " the yields on the difi'erent plats w'ere too 

 uneven to w^arrant any conclusions." 



In both cases it is plainly shown that sweet potatoes may be grown with chemical 

 manures alone. Since the second-size iiotatoes are saleable the influence of fertilizers 

 upon size of roots is worthy of notice. The average total yield of unfertilized land in 

 experiment No. 1 was 21.5.7 bushels, of which .56.3 bushels or 26 per cent were small 

 potatoes ; the average total yield of all fertilized plats was 286.4 bushels, of which 52.1 

 bushels or 18 per cent were small. In experiment Xo. 2 the average yield of the unfer- 

 tilized laud was 20 Imshels, of whidi 5.2 bushels or 20 per cent wcic small; the 



