

Vol. XIX, Second Series. 



ROCHESTER, N. Y., JUNE, 1858. 



No. 6. 



EXPEEIMENTS ON THE GROWTH OF BARLEY BY 

 DIFFERENT MANURES. 



The last Journal of the Royal Agricultural 

 Society contains tlie results of a series of experi- 

 ments "ou the growth of barley by different 

 manures, continuously on the same land," by 

 Messrs. Lawes & Gilbeet, of Rothamsted, Eng- 

 land, The paper is a most able and elaborate one, 

 occupying about eighty pages of the Journal^ and 

 contains so many interesting and important results, 

 that we fear it will be impossible to do justice to 

 the subject in the limited space at our oommand. 



The barley wiis grown each year on the same 

 land for six consecutive years. The plot left en- 

 tirely without inanure, each year, produced in th-e 

 six years 166 bushels, or an average of nearly 28 

 bushels -per acre per annum. That di'essed each 

 year with "mixed alkalies" (300 lbs, sulphate of 

 potash, 200 lbs, sulphate of soda, and 100 lbs, sul- 

 phate of magnesia,) produced in six ycai's 173 

 bushels, or an average of nearly 29 bushels per 

 acre — only one bushel per acre more than wdiere 

 no manure at all was used, 400 lbs, of superphos- 

 phate of lime per acre each year produced an aver- 

 age of 31 bushels; a plot with "mixed alkalies" 

 and superphospliate, 34 bushels ; 14 tons farm-yard 

 manure per acre each year, an average of 43 bush- 

 els per acre ; 275 lbs, nitrate of soda, 42 bushels ; 

 100 lbs, each sulphate and muriate of ammonia, 

 38^ bushels ; same quantity of -ammonia salts with 

 600 lbs. "mixed alkalies," 39^ bushels ; same quan- 

 tity ammonia salts and 400 lbs, superphosphate of 

 lime, 45^ bushels per acre ; same quantities of am- 

 monia salts, "mixed alkalies," and superphosphate, 

 46 bushels. 



It is evident that, like wheat, barley requires for 

 its maximum growth more nitrogen or ammonia 

 than the atmosphere can supply. Our own experi- 

 ments indicate that such is the case with Indian 

 corn ; and Mr, Lawes intimates, hi a private letter, 

 that, from a series of experiments he has made on 

 meadows, that such is the case with the grasses. 



Superphosphate of lime and the mixed alkalies 

 had a much better effect on barley than they had 



on wheat — a result which Mr. Lawes attributes to 

 the limited range of the roots of the barley plant 

 as compared 'with wheat. Still, though mineral 

 manures had some effect, it is quite evident that 

 the principal substance required for the groAvth of 

 a large crop of baidey, as of wheat, is nitrogen 

 (ammonia). 



Tills conclusion is also confirmed by the results 

 of another series of experiments given in the same 

 paper. Barley was sown on land from which ten 

 successive crops of turnips had been removed. 

 One plot had received no manure for the past seven 

 years, and another plot adjoining had received a 

 heavy annual dressing of the various mineral ma- 

 nures ; and yet the crop of barley was as large on 

 the unmanured plot as on that which had received 

 for so many years a liberal supply of minerals. 

 The minerals had been appHed for years; and 

 though a portion had been removed in the turnips, 

 yet there was a large excess remaining in the soil, 

 and that not in a crude condition. If, as Prof. 

 Way says, "the soil is a stomach," these minerals 

 must have been thoroughly digested, and rendered 

 fit for assimilation by the plants, and yet they had 

 no effect. Could we have stronger proof of the fact 

 that no amount of merely mineral plant-food will 

 produce maximum crops of barley in the absence 

 of nitrogen or ammonia ? 



In Mr. Lawes' experiments on wheat, an appli- 

 cation of nitrogen (ammonia) always gave an in- 

 creased yield of wheat ; but the nitrogen contained 

 in the increase yield of produce was in no case 

 equal to the amount of nitrogen supplied in the 

 manure. From this fact, which does not rest on a 

 single experiment, but on a very extensive series of 

 experiments, continued for fifteen years, it seems 

 evident that wheat destroys nitrogen during its 

 groicth. From the similar chemical composition of 

 barley, oats, rye, Indian corn, sugar cane, and the 

 various grasses, it is probable that all these plants 

 also destroy nitrogen during their growth. If this 

 is the case, it follows that the extensive cultivation 

 of these crops greatly unpoverishes the soil of nitro- 

 gen, and that the great aim of all grain-growing 



