Agricnlture is the most Hezdthy and Honorable, as it is the most Natural and Useful pursuit of Man. 



VOL. XII. 



ROCHESTER, N. Y. — MAY, 1851. 



iNO. 5. 



THE PROGRESS OF AGRICULTURAL KNOWLEDGE 

 DURING THE LAST EIGHT TEARS. 



The above is the title of an extended and valuable 

 essay by P. H. Pusey, M. P., editor of the Journal 

 of the Royal Agricultural Society, which appears in 

 the last volume of that excellent work. The eight 

 years immediately preceding the commencement of 

 the last half of the i9th century, will long be remem- 

 bered for the new impulse given to agricultural im- 

 provements in the most civilized and best-informed 

 nations of Europe and America. It is within the 

 period named, that farmers in Englanc', and in this 

 country have fairly comprehended the fact that agri- 

 culture is a science more varied and comprehensive 

 than almost any other in the whole range of human 

 knowledge. The successful study of its numerou- 

 phenomena and practical truths, is the work of a life- 

 time. Hitherto very little progress has been mad - 

 in any country from the want of cordial co-operation 

 for the advancement of knowledge between practical 

 and scientific men. Mr. Pusey thus alludes to the 

 labors of Baron Liebig ; "That eminent philosopher 

 prepared and sold under a pa ent, manure containing 

 the mineral ingredients so prepared as to be slowly 

 soluble, and therefore to supply to wheat what was 

 wanted, when it was wanted. Ammonia was omitted, 

 it was thought it would be supplied by the air. The 

 scientific manure was applied, but the wheat did not 

 mend." The mineral theory then eagerly adopted 

 was contained in the following axiom of Liebig : — 

 "The crops in a field diminish or increase in exact 

 proportion to the diminution or inc^•ease of the min- 

 eral subsances conveyed to them in manure." 



This doctrine received its death-blow from Mr. 

 L awes' experiments at Rotbamstcad, in the follow- 

 ing manner : — Plants, it is well known, consist 

 chiefly of oxygen, hydrogen, nitrogen, and carbon ; 

 the gas first named forming water by uniting with the 

 second, air with the third, and carbonic acid with 

 the fourth. These invisible gaseous bodies form 

 what are called the organic elements of plants, lint 

 when burnt, they all yield an incombustible ash, 

 which is called the inorganic, or mineral part of veg- 

 etables. Baron Liebig's theory was that the supply 

 of this earthy part of plants removed in crops was all 

 that the farmer need trouble himself about. To test 

 this chemical suggestion, Mr. Lawes tried sundry 

 experiments with the following results : — An unma- 

 nured field gave 16| bushels of wheat per acre. — 

 One manured with 700 lbs. of superphosphate of lime. 



(similar to burnt bones) yielded the same quantity. 

 Eight lots fertilized with various phosphates, also 

 gave 16g bushels per acre. The ash of 14 tons of 

 farm-yard manure gave but 16 bushels ; while an 

 equal quantity of manure gave 22. These four ex- 

 periments demonstrated tiiat on land devoid of mould 

 or organic elements, fertilizers containing such ele- 

 ments are indispensable. Hence, Baron Liebig's 

 theory that cereals can derive all their carbon and 

 nitrogen from the atmosphere is proved to be incor- 

 rect. The subject, however, is far from being 

 exhausted ; for the question still remains to be de- 

 cided how far carbon may be dispensed with in ma- 

 nure as in guano, and by what means ammonia or 

 nitric acid can be most economically added to a soil 

 in which one or b th of these fertilizers are lacking. 

 Ashes (done, whether of forest trees, crops, or good 

 manure, will not sufBce to give a fair yield of wheat 

 on exhnusled land. Upon land not exhausted, but 

 abounding in rich soluble mould, the effect of wood 

 ashes is very beneficial to wheat. When Mr. 

 Lawks applied various salts to the amount of 619 

 lbs. to supply the mineral elements of a crop of 

 wheat on exhausted land, without benefit, by the addi- 

 tion of 156 lbs. of rape seed cake, (nitrogenous mat- 

 ter,) the crop was increased from 16 to 22| bushels per 

 acre. In another experiment, 646 lbs. of mineral 

 salts aided by 80 of sulphate of ammonia, the crop was 

 raised from 16 to 26| bushels. This result is the 

 more noticeable from the fact, that no carbon, (coal,) 

 was added to the soil in the manure ; while the sup- 

 ply of nitrogen, sulphur, phosphorus, potash, magne- 

 sia, chlorine, fee, was abundant. 



The scientific reader will not fail tov/eigh the fact 

 that 80 lbs. of sulphate of ammonia increased a crop 

 of wheat from 16 to 26 J bushels, while 14 tons of 

 barn-yard manure increased it only to 22 bushels. 

 Mr. Lawes and Mr. Pusey ascribe this remarkable 

 gain to the available nitrogen in the ammonia ; but 

 we think that the sulphur in the fertilizer contributed 

 to the result. Mr. Pusey says " upon these experi- 

 ments rests the now established doctrine that nitro- 

 gen is what white crops require. And it may gen- 

 erally be assumed for practical purposes, that if 

 ammonia be supplied to wheat, it will find the min- 

 eral ingredients for itself, either in the soil or in past 

 or present dressings." This is doubtless true, espec- 

 iallv on highly manured land in England. 



Mr. Lawks' experiments on turnips are more 

 complicated, and as the culture of this renovating crop 

 is li'itle practiced in this country, we shall pass on to 



