were
done to the soil, in qualifying it for the production of the subsequent
crops of a course of rotation. In Peru it is used topically, but such
applications are always followed by immediate irrigations of the soils
to which it is applied, the Peruvians acting upon the philosophical
principal, whether they comprehend its theory or not, that to secure the
nutrient properties of this active fertilizer to their growing crops, it
is essential that they provide an absorbent, and that they find in the
water furnished by their processes of irrigation. Experience, practice,
and irrigation have taught them, that unless they cause the carbonate of
ammonia, and the various compound substances with which it exists in the
guano, to descend speedily to the roots of their plants, that from the
volatility of its more active and efficient elements, they will be
expelled by the heat of the sun, escape into the air, and be lost for
all the purposes of vegetable growth.

"But in view of the whole ground, taking into consideration the
evanescent nature of any ammonia in guano in the compounds in which it
exists, to be converted into that form, we honestly believe, that so far
as lasting benefit to the land may be concerned, guano should be
ploughed in.

"In all tolerably good Guano, there is a sufficiency of the carbonate
already formed to carry on healthful vegetation, and therefore, it is
best to place it sufficiently deep to prevent the waste of an element so
essential to the growth of plants, and so liable to loss.

"It is possible where the soil had been, by repeated harrowings, reduced
to a state of very fine tilth, that guano may be covered sufficiently
deep with the Cultivator to become mixed with, and consequently be
absorbed by the vegetable remains of the earth, and thus be prevented
from loss by escape of its volatile gases; especially would this be the
case, if the process of cultivating it in, were soon after followed by
penetrating rains. In admitting this, we still adhere to the opinion,
that so far as permanent benefits are concerned, the most economical
mode of applying guano to the earth, is by the plough.

"As soon as the guano is ploughed in, the wheat should be sowed and
harrowed in, in the usual way. In our climate we can sow wheat on the
poorest corn ground late in November and have as fine a crop, and
harvest it as soon, as we can obtain from well prepared and fallowed
without guano sowed early in the season,