282 TALKS ON MANURES. 



ammonia alone. This result nui}' be ascribed to the fact previously 

 alluded to — the ashes dissipated some of the ammonia. 

 "Plot 11, with lOU lbs. of plaster, 400 lbs. aslies, 300 lbs. of super- 

 phosphate of lime, and 20C lbs. Peruvian guano (whieh contains 

 about as much ammonia as loO lbs. sulphate of ammonia), pro- 

 duced precisely the same number of total bushels per acre, as jdot 

 4, with 150 lbs. sulphate of ammonia alone, and but 4 bushels more 

 per acre, tliau plot Vi, with :200 lbs. Peruvian guano alone. It is 

 evident, from these results, that neither ashes nor phosphates had 

 much effect on Indian corn, on this impoverished soil. Plot 14 re- 

 ceived the largest dressing of ammonia (500 lbs. Peruvian guano), 

 and produced much the largest crop; though the increase is not so 

 great in proportion to the guaao, as where smaller quantities were 

 used. 



"The manure which produced the mo.st profitable result, was 

 the 100 lbs. of plaster, on |)lot 2. The 200 lbs. of Peruvian guano, 

 on plot 13, and whidi cost about $0, gave an increase of 14 bushels 

 of slielled corn, ami G l)usbels of ' nubbins.' This will pay at the 

 present price of corn in Rochester, although the profit is not very 

 great. Tiie superphosphate of lime, although a very superior 

 article, and estimated at cost price, in no ease paid for itself. The 

 same is true of the ashes. 



"But the object of the experiment was not so much to ascertain 

 what manures will pay, but to ascertain, if possible, wlial constitu- 

 ents of manures are required, in greatest quantity, for the maxi- 

 nmm growth of com. * * Hitherto, no experiments have been 

 made in this country, on Indian corn, that afforded any certain in- 

 formation on this point. Indeed, we believe no satisfactory experi- 

 ments have been made on Indian corn, in any country-, that throw 

 any definite light on this interesting and important question. A 

 few years ago, Mr. Luwes made similar experiments to those given 

 above, on his farm, at Roth;imsted, England ; but owing to the 

 coolness of the English climate, the crop did not arrive at maturity. 



"Numerous experiments have been made in this country, with 

 guano and superphospliate of lime; but the superphosphates used 

 were commercial articles, containing more or less ammonia, and if 

 they are of any benefit to those crops to which they are applied, it 

 is a matter of uncertainty whether the beneficial effect of the appli- 

 cation is due to the solul)le phosphate of lime, or to the ammonia. 

 On the other hand, guano contains ])otli ammonia and phosphate; 

 and we are equally at a loss to determine, wiietiier the effect is at- 

 tributable to the ammonia or phosphate, or both. In order, there- 

 fore, to determine satisfactorily, which of the several ingredients 



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