42 



The Country Gentlemaiis Magazine 



then 4, and then 9. There was not very 

 much difference in the appearance of the 

 other plots, that is to say, the nothing plots 

 and the remainder of those dressed with arti 

 ficials alone. On the 5th August, they were 

 again carefully looked at, and the note made 

 that the plots having most sulphate of am- 

 monia were looking best. 



THE RESULTS OF THE EXPERIMENTS. 



The different plots were Hfted and weighed 

 on 2d November. They were dressed over 

 i^ inch riddle, the large ones [and the 

 small separately weighed, and pitted. No 

 diseased tubers were taken out at this time. 

 They were left in the pits until the 15th 

 March last, when they were dressed over, the 

 diseased ones thrown out, and the sound ones 

 weighed. This was done for the purpose of 

 ascertaining which of the manures tended 

 most to increase the spread of disease. As 

 already stated, although the plots were only 

 ^tli of an acre each, the following results 

 are all calculated to the imperial acre : — 



THE INFLUENCE OF ARTIFICIAL MANURE. 



The first point to which I would wish to 

 call your attention in regard to these experi- 

 ments is the quality of the ground, as indi- 

 cated by the returns from the plots which got 

 no manure, as well as by plots i and 16 and 

 plots 2 and 15, which were respectively 

 manured alike. The average of the four 

 nothing plots is 5 tons 3 cwt. i qr. 22 lb. 

 p€r acre ; while the lowest of these plots only 



differs 2 cwt. 2 qr. and 26 lb. from that aver- 

 age, and the lowest plot is only 3 cwt. 3 qr. 

 20 lb. less than the highest of them. Again, 

 you will observe that the difference between 

 plots I and 16, situated at opposite sides of 

 the experiment ground, and which were 

 manured alike, is very slight. The same re- 

 mark applies to plots 2 and 15, which were 

 also manured alike. All this shews that the 

 ground was of remarkably uniform quality, 

 and, so far, most suitable for such a set of 

 experiments. I will now ask your attention 

 to some of the most important points brought 

 out by these experiments. In the first place, 

 the influence of sulphate of ammonia 

 is very marked, either alone, or in com- 

 bination with the other manures. In every case 

 it has caused a very considerable increase 

 of crop. Even when, as in plot 10, 4 cwt. 

 alone was used, the crop reached a total of 

 8 tons 18 cwt. 3 qr. 4 lb. per acre, being 3 

 tons 15 cwt. I qr. 10 lb. above the average of 

 the nothing plots. Again, in plot 9, where 



2 cwt. of sulphate of ammonia was used in 

 conjunction with 4 cwt. dissolved coprolites, 

 the results obtained were still more favourable, 

 viz., 9 tons 9 cwt. and 16 lb., being 4 tons 5 

 cwt. 2 qr. 22 lb. above the average of the 

 plots which got no manure. Plot 4, again, 

 where the same manure was used as in plot 

 9, with the addition of 2 cwt. potash salts per 

 acre, the results were fully as favourable ; 

 while plot 5, which got 4 cwt. of sulphate of 

 ammonia and 4 cwt. superphosphate per 

 acre, gave the very large return of 1 2 tons 



3 cwt. I qr. 12 lb., being 6 tons 19 cwt. 3 qr. 

 18 lb. above the nothing plots. Potash salts 

 alone and dissolved coprolites alone gave only 

 a very trifling increase over the nothing plots. 

 Kainit in combination with sulphate of am- 

 monia, as in plot 8, gave a less return by i 

 ton 2 qr. 16 lb. per acre than sulphate of am- 

 monia alone. This result is doubtless due to 

 such a large dose of saline manure as 8 cwt. 

 per acre coming into too direct contact with 

 the roots of the plant. In this case, had one- 

 half the quantity been mixed with the soil 

 previously, and the other half applied in the 

 drill, the results would in all probability have 

 been somewhat different. The addition of 



