Field Experiments on Mangolds. 
153 
1 cwt. of guano, practically speaking, had the same effect as 
3 cwts. of superphosphate and 2 cwts. of potash sahs. 
5. 3 cwts. of Peruvian guano yielded an increase of 5 tons per 
acre, and appears to have had a better effect than either a lull 
dressing of larmyard manure or half a dressing and 1^ cwt. of 
superphosphate. 
6. Lastly, it will be noticed that the addition of a small 
quantity of nitrogen to the mixture of mineral superphosphate 
and potash salts produced a considerable increase. 
On Plot 7 we have the same quantity of superphosphate and 
potash salts as on Plot 3, with the addition of 1 cwt. of sulphate 
of ammonia per acre, and the effect of this addition of sul- 
phate of ammonia was to raise the produce to 30 tons 10 cwts. in 
round numbers, or to give 5J tons more than the superphosphate 
and potash salts without ammonia. 
Practically speaking, the same effect which the sulphate of 
ammonia produced in conjunction with potash and superphos- 
phate was obtained on Plot 9, on which the nitrogen was 
applied in the shape of nitric acid instead of that of ammonia ; 
for both the Plots, No. 7 and No. 9, the addition of nitrogen 
to available phosphates and potash has proved very beneficial to 
the mangold crop, producing an average increase of 8 tons in 
round numbers. 
Experiments on Mangolds at Escrick Park, near York, in 1869. 
The mangolds were sown on 11th May, 1869, on a barley 
stubble in 1868. The soil of the experimental field was of a 
light sandy character, and, though naturally poor, it was in a 
good agricultural condition, as the produce from the unmanured 
plot showed. 
The mangold crop was taken up, topped, tailed, and weighed, 
on the 11th November, 1869, when the following results were 
obtained : — 
Results of Experiments on Mangolds at Escrick Parle, near Yorlc, 1869 . 
Plots of 
55 of 
na acre. 
Manure per Acre. 
Produce per Plot of 
1 of an Acre. 
53 
Produce per Acre. 
Tons. 
cwts. 
lbs. 
Tons. 
cwts. lbs. 
1 
1 
2 
56 
22 
10 0 
2 
Mineral Superphosphate 3 cwts. . . 
1 
3 
."56 
23 
10 0 
j Mineral Superphosphate 3 cwts. .. ) 
.3 
I and [ 
1 
9 
28 
29 
5 0 
j Mineral Superphosphate 3 cwts. .. j 
4 
1 and > 
1 
6 
0 
26 
0 0 
(Peruvian Guano .. .. 1 cwt. ..) 
