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r ) 234 THE GENESEE FAEMEE. / 



have seen a far abler chemist labor for a longer period, with a like result. Phosphoric 

 acid and potash are the two most difficult substances to determine in an inorganic 

 analysis ; and without an accurate quantitative determination of these, a soil anal3'sis is 

 of no value. We can not, then, learn much from soil analyses as they are at present 

 'found in our publications. From what we do know, however, Ave may safely conclude 

 that potash is more plentiful in most soils than phosphoric acid ; and we have seen that 

 in the grain of wheat, maize, barley, oats, and more especially in the bones and flesh of 

 animals, phosphoric acid is exported from the farm in greater quantity than is potash. 

 It follows that phosphoric acid will be sooner deficient in our soils than potash, and 

 therefore sooner than any other inorganic constituent of plants. If our premises are 

 right, it also follows that an ordinary soil in common good practice can not be exhausted, 

 or even impoverished, of any inorganic substance except phosphoric acid, unless indeed 

 phosphoric acid be artificially supplied ; for plants will not grow at all unless every one 

 of their constituent elements are present in the soil : and as phosphoric acid is Jiy-st 

 exhausted, there can be no further removal of potash, or any other substance, by ordi- 

 nary crops after such exhaustion. 



We have shown, then, that in consequence of the destruction of ammonia by the 

 growth of cereals, ammonia is exhausted sooner than any other organic substance ; and 

 of inorganic substances, phosphoric acid is the only substance that can be exhausted 

 from the soil without the aid of artificial manures containing phosphoric acid in large 

 quantity. If a. soil once produced good crops of wheat, and now refuses to do so, it 

 must be owing either to a deficiency of ammonia or of phosphoric acid. On many soils 

 in Western New York, where fifteen bushels per acre is an average yield of wheat, we 

 generally obtain two tons of dry clover per acre after the wheat. According to Prof. 

 Emmons, this clover would contain at least 30 lbs. of phosphoric acid, or sufficient for a 

 cro]3 of wheat and straw of fifty bushels per acre. It is plain, then, that in such cases 

 the reason why we do not get a larger crop of wheat is not owing to a deficiency of 

 phosphoric acid in the soil, and consequently of no other mineral ingredient, but to a 

 want of ammonia. 



There are many soils, however, that will not produce good crops of red clover, peas, 

 beans, &c. In such cases the soil is probably deficient of phosphoric acid. If the defi- 

 ciency is caused by the won-availability of the phosphoric acid and not to its actual 

 exhaustion, rest and summer-fallow, by the disintegrating influence of the atmosphere, 

 will for some time supply it. If none exists in a latent condition, it must be supplied 

 artificially. In this there is no difficulty except a pecuniary one. There is an immense 

 quantity of phosphoric acid existing in several mineral deposits in various parts of the 

 United States. Iliis can be rendered soluble and available by admixture with sulphuric 

 acid. Animal charcoal, bones, and Mexican and other guano, also contain large quan- 

 tities of phosphoric acid. 



The great question, Will it pay to use these? can alone be determined by each indi- 

 vidual farmer and gardener for himself. It is absurd to say that their application will 

 be profitable in all cases. In many of the new States there is plenty of poor land that 

 will not produce good crops without manuring; but does any one suppose that it would 

 pay to apply guano or superphosphate of lime on such land to corn which, raised on the 

 fertile soil around, can be sold for 25 cents per bushel. If all land was naturally poor 

 or impoverished by cultivation, and we had, like Great Britain, but a small island, and 

 not a boundless continent, we might, if judicious, always use natural and artificial 

 manures with profit. But this is not the case. In prodi^cing wheat and corn, as in 

 raising and fatting stock, the poor soil must compete with the rick ; and the economy 

 of its cultivation depends on its location and the price its products command. There is 

 a connection between the cost of manure and the price obtained for the crop, which is 

 not sufficiently taken into account by those who advocate the use of artificial manures. 



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