Arable Lands in Dry Climates. 
341 
marl. Without this, indeed, every other attempted method of 
improvement may be nearly thrown away. Calcareous marls are 
much the best for all sorts of light soils of a sandy nature. Marl 
not only acts upon the soil, mechanically changing its texture so 
that it will retain more moisture, but also partly as a manure and 
a conservative of every other fertilising substance, such as dung, 
sheep's droppings, or any artificial manures which may be applied 
as top-dressings. There are clays which appear alike to the eye, 
but possess very different manurial values. The most calcareous 
marls readily shatter to pieces after having been exposed to frost 
in winter, or after having been dried in summer, and crumble to 
pieces when wetted. A few drops of muriatic acid applied to the 
best marls make a considerable effervescence at once. Such marls 
or clays as neither slack to pieces after exposure to the weather, 
nor effervesce on the application of an acid, should be avoided. It 
frequently happens that clay-marls of a good and of a bad kind may 
be found within a few yards even of one another. I have seen 
some very bad clay applied to sandy soils — some of the pipe-clay, 
or porcelain, kinds, which never mix properly with the soil, but 
are found in fragments, as plastic cakes, or hard knobs, according 
to the weather. It is a great error and a great loss when an expen- 
sive improvement is attempted with a bad clay. When good 
marl cannot be found within a moderate distance from where it is 
wanted, chalk, or what is locally termed hurlock, may be used 
as a substitute. Lime on all but the poorest sands may also take 
the place of either marl or chalk. I have tried lime, gas-lime, 
and marl in the same field, one against the other, and found the 
results very similar. On some poor ground which had once 
grown furze, gas-lime made the most rapid improvement. Even 
after well dunging, and also applying artificials, some ground 
failed to produce half a good crop, year after year, until gas-lime 
hot from the retorts was used ; then the following crop was really 
better than that of the rest of the field, and every crop for years 
has succeeded very well. The cost of filling, carting, and 
spreading marl, is generally about equal to buying lime ; but 
various circumstances should guide any one as to the probable 
comparative cost and ultimate results. 
I have seen some mere barren sand converted into a pretty 
good soil by first trenching 18 inches deep, then marling, and 
afterwards following up with plenty of manure. True, the various 
improvements cost as much as the land in its once barren state ; 
but this does not affect the question in the mean time, as it is not 
one of cost, but how moisture is to be retained. I may add, 
however, that the land referred to carries average crops, and is 
so much increased in value as would cover every expense, looking 
from a landowner's point of view. 
