WAR-TIME LIMING IN ESSEX. 245
(approximately below pH 5.2) and naturally it is an increase
in this type of crop that is desired. Land which needs liming
in order to produce satisfactory crops of wheat, barley, sugar-
beet, or any other crop able to grow only on a non-acid soil
requires some quickly available form of chalk or lime. Quick-
lime certainly fulfils this requirement, but, for a variety of
reasons it has been found impossible to increase the output
of this material, whilst, as stated above, chalk has certain ad-
vantages over lime for use on the Essex clay lands.
The lime trade in common with all other industries found
itself suffering from a shortage of labour after the outbreak of
war. Greatly increased production of quicklime was impossible
because of the lack of skilled lime-burners, whilst the heavy
fuel consumption necessitated by the moisture content of chalk
rendered such processing undesirable under war-time conditions.
The soft nature of chalk allows it to be dug with comparatively
unskilled labour, whilst the same quality renders it extremely
tractable for handling by mechanical excavators. The lump
chalk obtained by these methods is still not able to give the desired
quick result and to overcome this difficulty mechanical crushing
has been resorted to in order to render the chalk quickly available
for the needs of the soil. It is found that a reasonable dressing
of pulverised chalk—about five tons per acre—further aided in
its disintegration by the elements, viz. frost and rain—affects
acidity in a few months after spreading. It will, therefore, not
be surprising to note that shortly after the outbreak of war
increased production of ground chalk commenced in Essex
and the eastern counties in order to meet the unprecedented
demand for some quickly available kind of lime.
One interesting tendency brought about by the war is the
use of by-product carbonate of lime in agriculture. Limestone
and chalk are primary raw materials for many industries and
examples such as water-softening, gas purification, dyeing and
the iron and steel trades quickly spring to mind. The by-
products of these and other industries are often some form of
calcium carbonate or calcium hydrate, usually in a finely divided
state, and thus quite suitable as a form of ground carbonate of
lime. The rapid growth of industry along the lower Thames-
side has resulted in the production of many thousands of tons
of valuable liming material, and advantage of the situation was
rapidly seized by the South Essex farmers soon after the out-
break of war. The migration of industry outwards from London
during the last few decades also resulted in scattered factories
supplying their quota of valuable by-product carbonate of lime
from mid and south-west Essex. The rise of the sugar-beet