84 BULLETIN OF THE BUSSEY INSTITUTION. 
The third division of the field was devoted to phosphates of lime 
applied in the ordinary proportions to the plots in Section C, and by 
equal money-values to the plots of Section CC. The standard of 
comparison in this case was the highest priced superphosphate. Upon 
Section D several nitrogenous manures were applied in chemically 
equivalent quantities, and Section DD was devoted to various salts 
and fertilizers not otherwise provided for ; they were applied, as nearly 
as might be, at the rates ordinarily used by farmers. 
It was no part of my plan to apply at this stage of the research 
any mixtures of fertilizers which could be regarded as complete ma- 
nures, or could pretend to compete with the dung of animals. It was 
thought that such mixtures, proper for the soil of the experimental 
field, could probably be best prepared in the light of the results of one 
or two years’ experience with single fertilizers. With the view, how- 
ever, of using mixtures in future years, a considerable part of the ex- 
perimental field, upon three sides of the portion occupied by the plots 
represented in the foregoing diagram, was left fallow for the present. 
Preparation of the Field, and Methods of Manuring and Planting it. — 
The entire field was ploughed four inches deep, April 5-7; it was 
then harrowed parallel with the furrows, and finally cross-harrowed, 
before the plots were staked out. With the exception of the dungs 
and peat and one heavy dressing of wood-ashes, which were measured, 
each of the fertilizers was carefully weighed and spread evenly upon 
the surface of the plots. The heavy manures, such as stable-manure, 
peat, lime, ashes, and leather-scraps, were spaded under ; bone-meal, 
fish-scrap, guano, flocks, oil-cake, and pearlash were raked in, while 
the superphosphates and various salts and chemicals were simply mixed 
with a portion of the earth of their respective squares, and then spread 
upon the surface of the ground, without spading or raking. 
The barley (ordinary two-rowed seed-barley, from Messrs. J. Breck 
& Son, of Boston) was sown towards the close of April at the rate of 
two buslels per acre, or 0.4 quart (== 292 grammes) to each of the 
5 & 5 metre squares. It was spread evenly upon the surface of the 
' ground, raked in as thoroughly as possible, and the soil smoothed 
down upon it with the flat of a spade. The ripe plants were finally 
pulled up by hand in order that they might be harvested free from 
weeds, and that each crop should be collected precisely in the same 
way and as completely as the others. The soil that adhered to the 
