Field Experiments on Root-Crops. 373 
IIksui.ts of SwEiiic Exri-uiMioNTS at Tudney Waiiren, AniNODoy. 
riots of 
55 of 
an Acre. 
Kinds and Quantities of Manures 
per Acre. 
Produce per 
Acre. 
Increase over 
Average Produce of 
Unniaiiurcd Plots 
per Acre. 
cwts. 
tons 
cwts. 
lbs. 
tons 
cwts. lbs. 
1 
10 
10 
60 
- 
Aliiieriil Siiporphosphato 
3 
i 0 
Q 
o 
i5-i 
0 
1 O 
1 
jNIineral Superphosphate . , 
3 
3 I 
IG 
1 
Ot> 
4 92 
( 
2 
Miueral Superphosphate .. 
3 
4 I 
and 
16 
3 
G4 
5 
0 100 
( 
Peruvian Guano 
1 
5 
Peruvian Guano 
3 
15 
C 
108 
4 
4 32 
I 
Mineral Superphosphate .. 
3 > 
and 
G 
2 
16 
11 
8 
5 
8 44 
1 
and 
I 
Sulphate of Ammonia 
1 , 
tons 
7 
20 
19 
10 
60 
8 
7 96 
cwts. 
1 
Mineral Superphosphate .. 
3 > 
and 
8 I 
2 
17 
3 
64 
6 
0 100 
1 
and 
Nitrate of Soda 
1 , 
tons 
10 1 
9 
I and 
cwt. 
19 
3 
84 
8 
1 & 
Mineral Superphospliate . . 
li 
3 
10 
and 
15 
15 
80 
4 
13 4 
Miueral Superphosphate .. 
11 
11 
14 
92 
3. That 3 cwts. of Peruvian guano per acre produced a 
smaller crop than an equal weight of mineral superphos- 
phate. 
In IMr. Wall's experiments Peruvian guano gave the best 
results, even rotten dung not excepted. The difference in the 
effect of guano in the north of England and in the county 
of Oxford, where Mr. Kimber's farm is situated, no doubt, is 
due principally to difference of climate in the two localities ; for 
it is well known that guano does not exert its full fertilising 
effect upon root-crops in a very dry season, and sometimes even 
does positive harm. 
4. That the addition of potash-salts to superphosphate in- 
creased but slightly the efficacy of the latter. 
5. That the effect of nitrate of soda in the combination in 
which it Mas used in Plot 8 was rather better than that of 
sulphate of ammonia in the same combination. 
