NfAXUKKS FOR rOTATOKS. 



259 



feet apart each way. Tlie following table shows the manures used 

 and the yield of ]><)tatoc*s per acre. 



EXPEKIMKNTS O.V POTATOES AT MoKETON FaBM, 



1>r~i iiiiTiMN 



■ c Manure.-* v*zit. > 



AI'I'UKU I-EH Al'K): 



1) OIASTITIK? 



^•1 

 II 



No manure i>5 



151) lb!'. Hulphatc of ammonia 14<) 



;«) li)i«. 7<a|MTplii)!<plmt<- of lime l."J2 



150 lb!<. ^ull)hato uf animouiu, and SUO lbs. 8U|>or[>huH 



I pimte of linic 179 



401 lb?*, of uiil<ath«<l xv.H)d-a«lies | HW 



lOOIbrt. pla.-«t(.T, iirvp-uni. or sulplmti' of limo,) 101 



400lb^. UDl.achi-d'«oo<l-:ishir' an 1 lai lb.". pluHter i 110 



400 lb!<. uiili-achcd \vuo(i-a>lic-!<. V*i lbi«. i«ulplmto of am- 



' nioiiia. .ind l(>i> lb:*, plii^t.r 109 



300 lbi$. rupiTpbo-ipbal-! <>f lime, l.'i I Iba. fiilphato of am- 



I niouia and lOO lb;*. iinb-acbL-d woodaxlii-H l.X 



1^ 



^1 





45 



H4 



The superpliosphate of lime w;is made expressly for experimen- 

 tal |>urp(ises, from calcined bones, ground line, and mixed with 

 stil|)huric acid in the proper prnportion.s to convert all the pho.s- 

 piiate of lime of the bont-s into the sDliible sup Tphospliatc. It wa«i 

 a purely min ral article, fn-e from ammoiiii and other organic 

 matt -r. It co>t about two and a half cents per pound. 



Tlie manures were deposited in the hill, covered with an inch or 

 two of soil, and tlie seed then pl:inle<l on the top. Where supcr- 

 piiospiiate of lime or sidp'.iate of ammonia was u.sed in conjunction 

 with ashes, tiie as'.ies were tir>t deposited in the hill and covered 

 with a little soil, and then the superphosphate or sulphate of am- 

 monia placed on the top and covered with soil before the seed was 

 planted. Notwitlist;mding this precaution, the rain washed the 

 sul|)liate of ammoni.i into the a.>hes, and decomposition, witii loss 

 of ammonia, was the result. This will account tor tlie less yield 

 on plot 8 than on plot 2. It would have been better to have sown 

 tlie ashes bro.idcast, but some previous experiments with Peruvian 

 guano on potatoes indicated that it was liest to apply guano in the 

 hill, carefully coverincr it with soil to prevent it injuring the .seed, 

 than to sow it broadcast. It was for this reason, and for the greater 

 convenience in sowing, that the manures were applied in the lull. 



Tlie ash of potatoes consists of about 50 per cent of potasii, and 

 this fact has induced many writers to recommend ashes as a manure 

 for this crop. It will be seen, however, that in this instance, at 



