On the Growth of Barley hy different Manures, Sfc. 495 



rape-cake ; which, of course, further contained mineral matters 

 and carbonaceous organic substance also. 



5th. On a plot with the same mineral manures for the turnips 

 as in Nos. 2, 3, and 4, and in addition during the sis. interme- 

 diate years — 1845 to 1850 inclusive — an average annual supply 

 of about 139 lbs. of nitrogen, given as a mixture of both rape-cake 

 and ammoniacal salts. 



It is not to our present purpose to discuss the relative amounts 

 of turnips grown on these five different plots. But it may be 

 stated generally, that the mineral manures alone, of No. 2, gave 

 very much larger crops than the unmanured plot No. 1 ; and that 

 the addition of the nitrogenous and other organic constituents 

 to the mineral manures, as on Nos. 3, 4, and 5, always gave a 

 further increment of increase. It should be added, however, that 

 the produce by the six years' addition of nitrogenous manures did 

 not, even in the eight years — that is, including the two which 

 succeeded the application — return in either of the three cases the 

 nitrogen in increase which had been supplied as manure. Where 

 nitrogen was supplied in the manure for the turnips, we should 

 therefore expect — unless it were evaporated or drained in some 

 form from the soil, distributed too widely throughout it, fixed in 

 it in an unavailable condition of combination, or in some way 

 dissipated during tlie growth of the plant — that there would be 

 some remaining available for the three succeeding crops of barley. 

 Indeed the object of growing the barley three years in succession 

 over these plots without any fresh manure, was to reduce them as 

 far as possible to an equal condition as to available nitrogen, 

 before commencing a new series of turnip experiments. 



Before giving the Table of the produce of barley obtained in 

 the three years — 1853, 1854, and 1855 — as above described, it 

 should be further explained, that in the second year of barley (1854) 

 a portion of the land, numbered 6 in the Table, which had the 

 mineral manures only for the turnips, received in the second year 

 of barley about 82 lbs. of nitrogen per acre in the form of ammo- 

 niacal salts ; the barley following again in 1855, but without any 

 further addition of nitrogen. Lastly, another portion with the 

 mineral manures alone previously (No. 7 in the Table), received 

 in the same year (1854), for the barley, about 82 lbs. of nitrogen 

 in the form of nitrate of soda ; and in the third year (1855) about 

 17 lbs. more nitrogen in the same form. 



The produce of barley obtained after ten years' turnips on these 

 seven plots is given in Table XII., which follows; — 



