bloweth where it
listeth brings fresh supplies of carbon on its wings with every breeze
to the mouths and throats of the greedy and eager plants that long to
absorb it.

It is quite otherwise, however, with the soil and its constituents.
Land, we all know--or if we don't, it isn't the fault of Mr. George and
Mr. A.R. Wallace--land is 'naturally limited in quantity.' Every plant
therefore struggles for a foothold in the soil far more fiercely and
far more tenaciously than it struggles for its share in the free air of
heaven. Your plant is a land-grabber of Rob Roy proclivities; it
believes in a fair fight and no favour. A sufficient supply of food it
almost takes for granted, if only it can once gain a sufficient
ground-space. But other plants are competing with it, tooth and nail
(if plants may be permitted by courtesy those metaphorical adjuncts),
for their share of the soil, like crofters or socialists; every spare
inch of earth is permeated and pervaded with matted fibres; and each is
striving to withdraw from each the small modicum of moisture, mineral
matter, and manure for which all alike are eagerly battling.

Now, what the plant wants from the soil is three things. First and
foremost it wants support; like all the rest of us it must have its
_pou sto_, its _pied-a-terre_, its _locus standi_. It can't hang aloft,
like Mahomet's coffin, miraculously suspended on an aerial perch
between earth and heaven. Secondly, it wants water, and this it can
take in, as a rule, only or mainly by means of the rootlets, though
there are some peculiar plants which grow (not parasitically) on the
branches of trees, and absorb all the moisture they need by pores on
their surface. And thirdly, it wants small quantities of nitrogenous
matter--in the simpler language of everyday life called manure--as well
as of mineral matter--in the simpler language of everyday life called
ashes. It is mainly the first of these three, support, that the farmer
thinks of when he calculates crops and acreage; for the second, he
depends upon rainfall or irrigation; but the third, manure, he can
supply artificially; and as manure makes a great deal of incidental
difference to some of his crops, especially corn--which requires
abundant phosphates--he is apt to over-estimate vastly its importance
from a theoretical point of view.

Besides, look at it in another light. Over large areas together, the
conditions of air, climate, and rainfall are practicall