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Vol. XIX, Sbcond Series. 



ROCHESTER, N. Y., APRIL, 1858. 



No. 4. 



IXPERIMENTS WITH AKTIFICIAL FERTILIZEKS 

 ON POTATOES. 



Last season, we made some experiments on 

 potatoes, with various artificial fertilizers. The 

 soil selected for the purpose was a light, sandy 

 loam, which has been under cultivation for many- 

 years, and has seldom if ever been manured. It 

 was a two year old clover sod, plowed about the 

 first of May, and harrowed till in excellent condi- 

 tion. The potatoes were planted May 22, in hills 

 throe and a half feet apart each way. Two or 

 three potatoes were planted in each hill, according 

 to size. Each experiment consisted of five rows, 

 with one row between each plot left without 

 manure. Hie following table will show the results 

 of the exfteriments : 



The superphosphate of lime was made expressly 

 for experimental purposes, from calcined bones, 

 ground fine and mixed with sulphuric acid in the 

 proper proportions to convert all the phosphate of 

 lime of the bones into the soluble superphosphate. 

 It was a purely mineral article, free from ammonia 

 jmd other organic matter. It cost about two and a 

 half cents per pound. The sulphate of ammonia 



was obtained from London, at a cost of about sevea 

 cents per pound. The ashes were from hard wood. 



The manures were deposited in the hill, covered 

 with an inch or two of soil, and the seed then 

 planted on the top. Where superphosphate of lime 

 or sulphate of ammonia was used in conjunction 

 with ashes, the ashes were first deposited in the 

 hill and covered with a little soil, and then the 

 superphosphate or sulphate of ammonia placed on 

 the top and covered with soil before the seed was 

 planted. Notwithstanding this precaution, the radn 

 washed the sulphate of ammonia into the ashee, 

 and decomposition, with loss of ammonia, was the 

 result. This will account for the less yield on Plot 

 8 than on Plot 2. It would have been better to 

 have sown the ashes broadcast, but some previous 

 experiments with Peruvian guano on potatoes indi- 

 cated that it was best to apply guano in the hill, 

 carefully covering 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, 

 tliat the manures were applied in the hill. 



It is well known that Peruvian guano is an excel- 

 lent manure for potatoes. In the same field on 

 which the above experiments were made, two acres 

 were planted with potatoes, in 1852, without any 

 manure, and two acres with 300 lbs. of Peruvian 

 guano per acre, sown broadcast. The two acres 

 without manure produced 238 bushels, and the two 

 acres dressed with guano 410 bushels, or an increase 

 of eighty-six bushels per acre. 



All our commonly cultivated crops contain pre- 

 citely thfe same elements; hut in very different 

 proportions. Now, it is very desirable to know 

 what element is required in the greatest quantity 

 for wiy particular crop. We have repeatedly shown 

 that an analysis of the plant affords no conclusive 

 evidence on this point. We can obtain this inform- 

 ation only by actual experiment with the different 

 elements of crops. Barn-yard manure contains all 

 the elements of plant-food ; and when an increase 

 of produce is obtained by its use, we are unable to 

 determine which element or elements had the most 

 beneficial action. The same is true of Peruvian 



