LIQUID MANURE.
The adoption of irrigation as a means of utilising sewage, suggests a
short consideration of the value of liquid manures. It has been a custom
on many farms to apply the liquid manure got from the oozings of
manure-heaps, the drainings of the farmyard, byres, stables, piggeries,
&c., directly to the soil. Indeed, so strongly has the belief in the
superiority of liquid manure over other manure been held by certain
farmers, that they have washed the solid animal excreta with water, in
order to extract from it its soluble fertilising constituents. The late
Mr Mechi was one of the foremost exponents of the value of liquid
manure. His farm of Tiptree Hall was fitted up with iron pipes for the
distribution of the manure over the different fields. Superphosphate, it
may also be added, as first made from bones by Baron Liebig, was applied
in a liquid form. As to the general merits of liquid manure, there can
be no doubt that it is the most valuable form in which to apply manure.
It secures for the manurial ingredients it contains a speedy and uniform
diffusion in the soil; but, on the other hand, the expense of
distributing it makes its application far from economical. The chief
ingredient in liquid manure is urine. Now the removal of urine from the
farmyard manure-heap entails a severe loss of the ingredient which is
most potent in promoting fermentation. Separation of the urine from the
solid excreta is on this very account not to be recommended. Urine, when
applied alone, is lacking in phosphoric acid, of which it contains mere
traces. It is not, therefore, suitable as a general manure. It has to be
pointed out, however, that the drainings from a manure-heap in this
respect are superior to pure urine, since they contain the soluble
phosphates washed out of the solid excreta. The objections against using
liquid manure may be summed up as follows:--
First, it is too bulky a form in which to apply the manure, and hence
too expensive; secondly, it is not advisable to deprive the solid
excreta of the liquid excreta, as the one supplements the other;
thirdly, fermentation is largely fostered in the solid excreta by the
presence of the liquid excreta--hence fermentation will not take place
properly in the solid excreta when deprived of the liquid excreta.
If, however, the production of liquid manure on the farm is in excess
of what can be used for the proper fermentation of farmyard manure, it
will be best to utilise it for composts. No better addition to a compost
can be made than liquid manure, as it induces speedy fermentation in
nearly all kinds of organic matter.