not only protect the tree but, once decomposed, provide an air duct
for ventilation. Into the hollow is placed a 20cm thick layer of Sun-
dried leafmould and vegetable matter. This is covered with an equally
thick mixture of earth, river gravel and fine sand. This is similar to
remineralization, just described. A small amount of copper and zinc
filings is added to this mixture (see p. 232).
To stop the compost heap getting wet, it is then temporarily cov-
ered with clay or some other waterproof material. Insects, earth-
worms, and micro-organisms are quickly attracted into the heap
because it is a cool process. Helped by the diffused oxygen, nitrogen
and other trace gases penetrating the newspaper round the trunk
and the layer of earth and sand, they begin to break down the
refuse.
The heap is built up into the stable shape of the egg shown in
Fig. 17.1, as more vegetable refuse becomes available. To protect the
cold decomposition from being spoiled by rain, the finished heap
is then coated with a layer of clay. Any rain will run down the near
vertical surfaces.
The earthworms and microbes will now have multiplied in their
thousands through the whole pile and aerated it. As they will begin
to die off, their bodies add nutritive value to the compost heap, hav-
ing by now infiltrated the whole of the compost heap. As the autumn
Sun loses its strength, the ground starts to cool and a significant
positive temperature gradient is established between the ground
and the air. The compost heap is now ready; it is taken down to
ground level, and what remains in the cavity is left to nourish the
tree.
The material is spread evenly over adjacent fields towards
evening, for under the positive temperature gradient — most pow-
erful at this time — rain or dew will carry the nutrients into the
ground. This method produces a far richer and higher-quality nat-
ural fertilizer, which not only maintains, but actually increases fer-
tility. The host tree also benefits and will produce a copious crop of
healthy, tasty and blight-free fruit. Such compost heaps may be
built under different trees each year, eventually fertilizing all the
fruit trees. If there are no suitable trees, similarly constructed
heaps can be built as dome-like humps or barrel-shaped clumps,
protected from rainwater and insulated from the heating effect of
the Sun.
HIDDEN NATURE