32 REPORT 1859. 



The land was left unmanured in the preceding year, and was considered a 

 poor turnip soil. 



I purposely selected a poor field ; for it strikes me on such a soil the ma- 

 nurial effect of different fertilizers is much better discerned than on land in 

 a high state of fertility. The productive power of soils cannot be increased 

 to an unlimited extent ; and when by good cultivation it approaches its maxi- 

 mum state of fertility, the addition of the most effective fertilizing matters 

 cannot produce any marked effect. I may, however, observe that care was 

 bestowed upon the mechanical preparation of the land, whicli is not always 

 done in field experiments. 



The experimental field was divided into ten different plots of one-eighth of 

 an acre each. These plots were arranged side by side in continuous rows of 

 drills, care being taken to reject the headlands. The different manures were 

 all applied to the land on the same day, and the Swedish turnip-seed sown by 

 a ridge-drill on the 20th of June. Subsequently all the plots were treated in 

 precisely the same way, and care was taken to render the experiments in every 

 respect comparative. 



One of the plots was left unmanured, the nine remaining were manured as 

 follows : 



Plot 1 received 56 Ibs. of Peruvian guano, or at the rate of 4 cwt. per 

 acre. 



Plot 2 received 84- Ibs. of Suffolk coprolites, treated with one-third their 

 weight of sulphuric acid and 28 Ibs. of guano, or at the rate of 6 cwt. of 

 dissolved coprolites and 2 cwt. of Peruvian guano per acre. 



Plot 3 received 100 Ibs. of bone-dust, or 7 cwt. 16 Ibs. per acre. 

 Plot 4- received 93 Ibs. of bone-dust dissolved in one-third its weight of 

 sulphuric acid, or at the rate of 6 cwt. 72 Ibs. per acre. 



Plot 5 received 56 Ibs. of economical manure, or at the rate of 4 cwt. 

 per acre. 



Plot 6 received 120 Ibs. of nut-cake, or at the rate of 8 cwt. 64- Ibs. per 

 acre. 



Plot 7 was manured with 140 Ibs. of dissolved coprolites, or at the rate of 

 10 cwt. per acre. 



Plot 8 was left unmanured. 



Plot 9 received 180 Ibs. of commercial night-soil manure, or at the rate of 

 12 cwt. 96 Ibs. per acre. 



Plot 10 was manured with a mixture of 1 bushel of soot, 30 Ibs. of guano, 

 and dissolved coprolites and dissolved bones. 



The respective quantities of these fertilizing matters were all obtained 

 at the same cost of 5s. per plot, or at the rate of 2 per acre. 



All the different fertilizers were carefully analysed ; but in order not to 

 swell too much this Report I abstain from giving the details of the analyses. 

 I may, however, observe that the guano contained 14*177 per cent, of nitro- 

 gen, and 25*06 of bone-earth, and nearly 3 per cent, of phosphoric acid 

 in combination with alkalies. We have "thus in Plot 1 a manure contain- 

 ing a large proportion of nitrogenized matters as well as phosphates and 

 alkalies. 



In Plot 2 only half the amount of guano was used, and phosphates more 

 largely supplied in the shape of dissolved coprolites. 



The coprolites, however, having been treated with only one-third their 

 weight of acid, contained scarcely more than 6 per cent, of soluble phosphates; 

 and it is to be feared that the remainder of the undissolved phosphates in the 

 coprolites exercised little or no effect upon the turnip-crop. 



In Plot 3 we have a manure which contains 4-4*22 of insoluble phosphate 

 of lime, and 4*28 per cent, of nitrogen. 



