388 Experiments with different Top-dressings upon Wlieat. 
progress of the experimental plots, it is a sore trial for the ex- 
perimentalist to have to report, " Results vitiated by the ravages 
of the black caterpillar." Indeed any one who is not prepared 
to meet with more disappointment than success, will be wise 
to desist from trying his hand at field experiments. I am led to 
make this remark because only the season before last my experi- 
ments upon swedes were entirely spoiled by the black grub. 
Again last season I instituted an extensive series of experiments 
with top-dressings upon barley, and, after having incurred con- 
siderable expense and taken much trouble, all that I can report 
is, " Results vitiated by the ravages of the wire-worm." 
My experiments upon the wheat-crop, I am happy to say, were 
unusually successful. No hail, drought, mildew, or rust, inter- 
fered with the success of the trials. I was fortunate enough to 
find a good and most equal plant on a perfectly level and uniform 
field of the Royal Agricultural College farm. The day on which 
the top-dressings were applied was calm and cloudy ; a moderate 
rain that fell on the next day washed the various manures into 
the soil, and secured at once their uniform distribution. The 
season, on the whole, was favourable to wheat, the weather at 
harvest time was unusually splendid, and on none of the experi- 
mental plots was the crop laid in the slightest degree. 
The field on which the experiments were tried is perfectly level, 
and throughout of uniform depth. Its extent is about 20 acres ; 
and last season the whole was in wheat after seeds ; 2 acres 
covered with a very equal plant were measured out for the expe- 
riments and carefully divided into 8 parts of equal length and 
breadth. Each experimental plot thus occupied the space of 
:|- acre. The 2 acres under experiment were surrounded by a 
considerable breadth of the general wheat-crop, except on one 
side. Although the headland, and a portion of the rest of the 
land, separated on that side the experimental plots fiom the ad- 
joining hedge, it was considered prudent to reject the \ acre next 
to the hedge. Seven plots of \ acre each in extent thus were left. 
These plots were manured as follows : — 
To Plot I. was applied 70 lbs. of Peruvian guauo ; or at the rate of 2^ cwt. 
per acre. 
49 lbs. of nitrate of soda ; or at the rate of If cwt. 
jier acre. 
45 lbs. of nitrate of soda and 42 lbs. of common salt ; 
or at the rate of 1^ cwt. of salt and 180 lbs. of 
nitrate of soda per acre. 
1 cwt. of Proctor's wheat mannre ; or at the rate of 
4 cwt. per acre. 
1^ cwt. of the same wheat manure ; or at the rate of 
G cwt. per acre. 
Plot VI. was left luimanured. 
To Plot VII. was applied aliout 1 ton of chalk-niarl : or at the rate of alcut 
4 tons per acre. 
II. 
III. 
IV. 
V. 
