288 



THE YEAR-BOOK OF AGRICULTURE. 



way ; seed planted whole. Hoed twice ; last time slightly hilled. We have made selections 

 from the principal results, and embodied them in the following table, which shows the pro- 

 duce of the three varieties without any manure, and the effect of the various fertilizers applied 

 in the hill at the time of planting. 



Description of the manures, and the quantity 

 applied in each hill. 



1, — No manure 



2. — 4 Bhovelful hog-manure 



3. — 4 " l°ngi unfermented manure.... 



4. — i " compost 



5. — Tablespoonful of guano 



6. — " " superphosphate of lime 



7. — " " gypsum or plaster 



8. — 4 handful of poudrette 



9. — Handful of wheat-bran 



10. — " fowl-manure 



11. — i handful of ashes 



12.— " lime 



Total number of 

 bushels per acre. 



J: = 



~ 3 



5 



1343 



282 

 179$ 

 152} 

 134J 



146H 

 150H 



Increase per acre 



from manure, in 



bushels. 



•5.3 



" 3 



o 



58 



32 



17 



14J 



24 



"{':" 



24 



3 



12* 



138 



374 

 66 j 



55 

 52* 

 10* 

 46 

 31* 

 23J 

 264 

 3 



147J 



45 



18 



00 



4 



12 

 16 



Quantity of i/n- 

 found potato 

 acre, in bushels. 



•7 - 



! 



a 

 O 



IS 



15s 

 84 

 li 



n 



4s 



"34* 



5* 

 54 



1 



1 



264 



20 



17* 



6 



3 



34 



94 



2 



21s 

 454 

 83§ 

 314 

 13$ 



38| 

 34 



There is a striking difference in the yield of the three varieties — the Mercer, in every case, 

 producing less than the Irish luukers and the Carters. They have, however, as a general 

 thing, fewer unsound potatoes. The Carters appear to be exceedingly liable to disease. In 

 one instance, No. 4, with compost, more than half, or eighty-three and a half bushels out of 

 one hundred and fifty-two and a half, were unsound. 



The hog-manure in the second, as in the first experiments, gives the greatest increase with 

 each variety. The Carters, with this manure, gave two hundred and eighty-two bushels in 

 the aggregate, or two hundred and sixty bushels of sound potatoes, per acre. In these days 

 of potato degeneracy, this is a good crop. Long, unfermented manure gives a compara- 

 tively poor crop with all the varieties. Poudrette, wheat-bran, hen-manure, and ashes have 

 but a slight beneficial effect. Lime gave no increase, and gypsum would seem to have done 

 more harm than good, since, with the Irish rankers, the plot receiving a tablespoonful of 

 plaster in the hill actually yields ten and a half bushels per acre less than that with no ma- 

 nun-. This confirms the common opinion that plaster has little or no effect on low, moist soil r 

 while "u dry upland it usually proves beneficial. In the fust year's experiments, on 

 "gravelly loam," plaster applied when the potatoes were up gave an increase of twenty-six 

 bushels per acre, and, applied in the hill at the time of planting, an increase of thirty-two 



liU-heN pi r iicn-. 



The comparative value of superphosphate of lime and guano for potatoes is a matter of 

 discussion just now, and we were in hopes thai these experiments would have thrown some 

 light on the subject. Unfortunately, however, die guano was applied in the hill with tin- 

 potato, and, of course, tl Beed was injured'' and the crop lessened. Under these circum- 

 stances, it is hardly surprising that the guano, except in one instance, gives a less in- 

 crease than the superphosphate. Our own experiments and observations on this point lead 

 us to tin- conclusion that good Peruvian guano is a far superior manure for potatoes than 

 Superphosphate "f lime. And, indeed, Mr. B. found, in another experiment with Irish 

 bankers, that guano, applied on the top of tht lull at the time of planting, produce- :i better 



nperphosphate of lime similarly applied. Thus the unmanured plot gave per 

 acre seventy eight and a half bushels; the superphosphate, one hundred and ten and two- 

 third- bushels; and tin- guano, one hundred and fifty-six bushels. It is said, too, that in thU 



1 was injured, though doubtless less so than where the guano was in actual 

 contact with the tubers. It is seen tb it the guano doubles the crop, ami gives forty-five 

 bushels per acre more than the superphosphate of lime. A tablespoonful of saltpetre (ni- 

 trate of potash) applied in the hi!l gave seventy-five and two-thirds lm-hels per acre, or three 

 bushels Ism than where nothing was applied. This is in accordance with the previous year's 



