ist, and must be
largely decided by economic considerations. There is an aspect, however,
of the question which may well be treated here. The first point in the
production of good manure is in connection with its even distribution.
It is of great importance that the excrements of the different farm
animals be thoroughly mixed together. By the intimate incorporation of
the "hot" horse-dung with the "cold" cow and pig dung, uniform
fermentation is secured. Fire-fang--or too rapid fermentation--may occur
from this not being properly done, and from the manure becoming too dry.
It is important, also, as we shall see immediately, to have the manure
uniform in quality when applied to the field. The manure ought to be
firmly trodden down, to moderate the rate of fermentation. Where the
manure-heap is exposed to rain, the quantity of water it will naturally
receive will probably be quite sufficient, if indeed not too much, to
ensure a proper rate of fermentation--except, perhaps, in very warm
weather. The great point to be aimed at is to ensure regular
fermentation. What has to be especially avoided is any sudden exposure
of the manure to large quantities of water. The result of such a
washing-out of the soluble nitrogen is to retard fermentation, besides
incurring the risk of great actual loss by drainage.[170]

_Application of Farmyard Manure to the Field._

In applying the manure to the field, and before ploughing it in, two
methods of procedure may be pursued. First, the manure may be set out in
heaps, larger or smaller, over the field, and be allowed to remain in
these heaps some time before being spread; and secondly, it may be
directly spread broadcast over the field, and thus allowed to lie for
some time. Lastly, the manure may be ploughed in immediately; and it may
be stated that such a method is, where circumstances permit, the safest
and most economical method.[171]

In discussing the merits and demerits of these two methods, Dr Heiden
points out, first, with regard to the distribution of the manure in
small heaps over the field, that this is not to be recommended, on the
following grounds:--

1. Because the chances of loss by volatilisation are thereby increased.
The manure is distributed several times instead of only once or twice.

2. It is apt to ensure unequal distribution. The separate heaps run the
risk of losing their soluble nitrogenous matter, which soaks into the
ground beneath the heaps. The other p