J^VpIj . - L^ 



1^ ) 3Q0 • THE GEKE8EE FARMER. (1 H 



demonstrated it by his experiments — that, in fact, for ev«iy pound of ammonia organ- 

 ized in the wheat plant, there is at least five pounds of ammonia used by the plant in 

 the performance of its functions. Mr. Lawes did not clearly perceive how and for what 

 purpose this destruction took place, but was nevertheless convinced of tlie fact. Recently 

 the experiments of Prof. Way render it exceedingly probable that ammonia is used as 

 the solvent and vehicle for carrying silicic acid to the plant, and evaporating when the 

 silica is deposited, just as water is known to do in depositing the elements of plants. 

 Chemists have always had a difficulty in accounting for the manner in which silica was 

 conveyed to the plant, the theory being that it was as a soluble salt of potash or soda, 

 and the patent of Prof. Liebig was for manufacturing this soluble silicate of potash, &c. ; 

 but from the fact that this patented manure has failed to increase the wheat crop, not 

 only in England, but in Germany, under the immediate superintendence of Liebig him- 

 self, it is more than probable that silica is not taken up as a silicate of potash. Admit 

 the opinion of Prof. Way, and we can account for the benefit of summer-fallow on 

 heavy soils — for the manner in which silica is deposited — and for the fact that in the 

 growth of wheat there is an immense destruction of ammonia, as there would also be in 

 the growth of all the cereals and other plants containing a large per centage of silica. 



Will Mr. B. examine and explain this theory, not from what we say about it, but 

 from the article itself, published in the last Journal of the Royal Agricultural Society 

 of England? 



In number three, of the series of letters, we have repeated assertions, but none of the 

 promised experiments or facts. Mr. B. says : " At the first glance, some might be led 

 to infer from the result of Mr. Laws' statements, (and there can be no doubt of their 

 correctness,) that the only thing needfid for growing good crops of wheat, was ainmonia, 

 in one form or another." Mr. Lawes most certainly never made any such '^ statemeut" 

 — but, as we have said before, Mr. B. does not know what Mr. Lawes has said, as he 

 evidently has not read his articles, is ignorant of the bearing of the subject in England, 

 and does not even know how to spell his name correctly. As our article on plowing in 

 green crops appeai-s to be the source of Mr. B.'s information, why does he not attempt 

 to refute the position there maintained by us, and not attack Mr. Lawes. We never 

 said, any more than Mr. L., that the only thing needful to grow good crops of wheat, 

 was ammonia. We say that every mineral which enters into the construction of the 

 plant, must be m the soil in sufficient quantity, and in an assimilable form ; and that if 

 any one is ab'sent, the j^lant will not grow at all ; if any one is deficient, there will be 

 a deficient crop : and this, though there is a liberal supply of ammonia. But that, 

 thouo'h there is an abundance of every inorganic constituent present in the soil, and in 

 an available condition, yet there will not be sufficient ammonia supplied from the 

 atmosphere to produce over an average of 17 bushels of wheat per acre ; and that if we 

 • wish for an increase over this amount, ammonia must be supplied artificially. 



We do not deny that there are some soils so rich in organic matter that an addition 

 of ammonia would be worse than useless, and that on such soils mineral manures will 

 be of great benefit ; but as a general thing, on most of our soils cultivated with wheat, 

 ammonia (on account of the destruction we have mentioned as taking place) is much 

 sooner exhausted than even phosphoric acid, which we hold to be the first mineral 

 element exhausted. We believe there is no better wheat-growing district in the United 

 States than Western New York; yet even here we do not average more than the 

 annual yield of wheat on the continuously unmanured acre in Mr. Lawes' experiments. 

 Why ? Is it because the minerals are deficient in the soil ? If so, why is it that we 

 can, without supplying any, still continue to grow wheat ? Wliy is it, too, that we can 

 obtain such splendid crops of clover, which contain precisely the same elements, and in 

 larger quantity than the wheat crop, excepting the single element silica, or sand. But 

 -] K of this no one for a moment supposes our soils are deficient. How is it, too, that plow- ^ r 

 W,=^ -—=--— ^4^ 



;^A^' 



^ 



