404 
Field Experiments on Potatoes. 
Plot 6. — Mineral superphosphate, crude potash-salts, and 
nitrate of soda. Sets irregular, hut of a good colour. 
Plot 7. — Peruvian guano. Sets regular, the tops were the 
strongest, and had a darker green colour than any of the other plots. 
Plot. 8. — Mineral superphosphate and common salt. Sets 
irregular, weak tops, and general unpromising appearance. 
Plot 9. — Rotten dung. Strong but pale green tops ; sets regular. 
Plot 10. — No manure. The same as Plot 1 and 5. 
Judging from the appearance of the potatoes on the several 
plots, common salt, and to a minor but perceptible extent crude 
potash-salts affected the sets injuriously at this early period. 
Subsequently the potatoes manured with superphosphate, crude 
potash, and sulphate of ammonia, and those planted with super- 
phosphate, crude potash, and nitrate of soda, recovered, and, as 
will be seen presently, produced good crops ; whilst those manured 
with superphosphate and common salt throughout the experi- 
mental period looked weakly, and finally gave but a slight increase 
over the average yield of the unmanured plots. 
Although the potatoes on Plot 7, dressed with Peruvian 
guano, at first looked very luxuriant and promising, the dry 
weather which set in subsequently sadly interfered with their 
progress. The guano plots evidently could not stand the inju- 
rious effect of the dry weather. 
On the other hand, the farmyard-manure plots were much less 
affected by the dry weather than any others. The produce of 
each plot was carefully weighed, and the following results 
obtained : — 
Table VII. — Showinci; the amount of Cloan Potatoes from eacli Experimental 
Plot of j'jjth of an Acre, and Weight calculated per Acre. 
Plots. 
Manures used per Acre. 
Weight ia 
Stones and lbs. 
per Plot. 
Weight per Acre. 
7 
8 
9 
10 
No Manure 
Mineral Superphosphate 
Crude Potash-salts .. 
Sulphate of Ammonia 
Good Rotten Dung .. 
Mineral Superphosphate 
Crude Potash-salts .. 
No Manure 
Mineral Superphosphate 
Crude Potash-salts .. 
Nitrate of Soda 
Peruvian Guano 
(■Mineral Superphosphate 
(Common Salt 
Good Eotten Dung .. 
No Manure 
4 cwts. 
2 
2 
20 
4 
4 
tons, 
cw 
^ts.j 
4 cwts. 
::l 
tons. 
Stones 
lbs. 
Tons cwts. 
qrs. 
lbs. 
27 
1 
3 
7 
2 
20 
65 
7 
8 
3 
3 
0 
60 
10 
7 
11 
3 
4 
58 
0 
7 
5 
0 
0 
22 
11 
2 
IG 
3 
24 
58 
12 
7 
7 
0 
16 
36 
0 
4 
10 
0 
0 
30 
0 
3 
15 
0 
0 
72 
0 
9 
0 
0 
0 
28 
12 
O 
12 
0 
16 
