THE GENESEE FAEMEt?. 



The ashes of fourteen tons of barn-yard manure, gave 10 hushels. Tlie average of the 

 seven years on the plot dressed with fovirteen tons of barn-y-ard manure per acre each 

 year, was 28 bushels. An acre dressed with 168 lbs. each of sulphate and muriate of 

 ammonia, gave 33^ bushels; another, with 150 .lbs. each of s.ulghate and muriate of 

 ammonia, 25|- bushels ; while a plot by the side of it, dressed wl^'^lSO lbs. each of sul- 

 jihate and muriate of ammonia, and 300 lbs. potass, 200 lbs. sod^J'lOO lbs. shlphate of 

 magnesia, 200 lbs. calcined bones, and 150 lbs. sulphuric acid, gave 55 bushels. Again, 

 with 200 lbs. each of sulphate and muriate of ammonia, we get 32^- bushels ; while 300 

 lbs. potass, 200 lbs. soda, 100 lbs. sulphate of magnesia, and 200 Jbs, calcined bone dust, 

 Avith 150 lbs. sulphuric acid, gave 17^- bushels. 224 lbs. sulphate of ammonia gave 21^ 

 bushels. 224 lbs. sulphate of ammonia, and the ashes of three loads of wheat straw, 

 gave 27 bushels. , 



These results, which we have selected as showing the general indications of the exper- 

 iments, will throw much liglit on our point — What amoimt of organic matter will the 

 atmosphere supply to a wheat crop on a soil having an abundance of inorganic constitu- 

 ents ? The average crop on the continually immanured acre was l7f bushels; and 

 where inorganic or ash constituents were supplied, the crop was not increased. But 

 when a salt of ammonia is used, the crop in some instances was doubled ; and in no 

 instance during the whole course of the experiments, has ammonia been used without 

 greatly increasing the crop. On one acre Avhere ammoniacal salts alone were used, the 

 average yield of six successive crops was 27 bushels. This clearly shows that there was 

 abundance of inorganic matter in the soil, but that for want of organic matter the plants 

 could not assimilate them. It can not be said that the wheat was not in favorable 

 circumstances for collecting organic matter from the air, for the land was always plowed 

 twice previous to sowing, and during the spring the crop was hand-hoed twice, and 

 sometimes thrice, care being taken to have all th^e plots hoed at the same time and 

 treated similarly in every mechanical operation. • 



AV^e therefore conclude that, though a soil-has an abundance of every inorganic con- 

 stituent of the wheat plant in an available boiidition for 40 bushels per acre, yet if there 

 is not a corresponding sufficiency of organic matter, but the plant is dependent solely on 

 the atmosphere, a crop aver^iging about 17 bushels otily Avill be obtained; and this may 

 be considered the natural yield of a soil, organic matter being derived from the atmos- 

 phere sufficient for this amoimt. If we wish to increase this yield, Ave must get an arti-' 

 ficial supply, or an accumulation, of organic matter in the soil ; and as organic matter 

 consists of four elem.cnts — oxygen, carbon, hydrogen, and nitrogen — it is important to 

 know which of these is the most essential. In the experiments above given, whefe 14 

 tons of barn-yard manure were each year used per acre, an average crop of 28 bushels 

 was obtained ; and where ammoniacal salts alone were used for six years, an average of 

 27 bushels. Now, besides a large amoimt of inorganic matter^ the 14 tons of barn-yard 

 manure contained an immense amoimt of organic matter — carbon, oxygen, hydrogen; 

 and nitrogen — and from the fact that the ammoniacal salts alone did as much good as 

 the minerals, carbon, and ammonia in the dung, we conclude that ammonia (hydrogen 

 and nitrogen) is the only organic matter that need be supplied to the wheat croj-*. The 

 rice, rape cake, and other carbonaceous manures used in the experiments, did good only 

 in a corresponding proportion to the nitrogen they contained. So that, to increase our 

 wheat crops over 17 bushels per acre, we must in some shape or other supply ammonia ; 

 or, what is equivalent, nitrogen. 



To obtain this ammonia, is the great difficulty in the way of increasing our wheat 

 crop. In Great Britain, immense quantities are purchased in the form of Peruvian 

 guano, and sulphate and muriate of ammonia;.,^! highly nitrogenous artificial foods 

 are purchased for cattle, which make a manure ©oSTSming a high per centage of am- 



monia. By this means their average wheat crop is -jiearly af'ift^ich again as ours. Since 



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