are a vital moderator of climatic extremes. They also tell how John
Hamaker was able to increase the depth of the topsoil at his Michi-
gan home, from about 10cm (4in) to about 1.2m (4ft) over a period
of 10 years.
More recently in Western Australia, an experiment by Barry Old-
field for the 'Men of the Trees' showed a remarkable increase in the
growth and health of seedlings planted with rock dust compared
with those without. Rock dust is easily available as a by-product of
road metal quarries.
An initial application of very fine rock dust will quickly attract
micro-organisms, but a mixture of small and large grains will allow
a slow release over a longer period. Rock dust has been shown to be
a buffer against nitrate, sulphur dioxide and nitroxide, and it
absorbs and fixes the negative ions while saving the positive ions
for the plants' use. Normally rock dust is applied about every five
years, the quantity depending on soil deficiency, although it is
always beneficial.^2
It is thought that the remarkable longevity (up to 140 years) and
health of the Hunza people of Northern Pakistan is as much due to
the mineral-rich glacial water, as to the clean mountain air. Callum
Coats tells of his neighbours in Queensland who fertilized their fruit
trees from a bucket of rock dust. Their dogs, who would eagerly
drink rainwater from this bucket, while leaving their usual water
bowls full, clearly knew what was best for them.Organic farming
Organic farming normally uses manure (generally cow's), farmyard
slurry and composted vegetable matter to increase the soil's fertil-
ity. The introduction of chemical fertilizers in the nineteenth cen-
tury was popular and soon supplanted the traditional organic
method, because it was much less labour intensive, and appeared to
give higher crop yields. A few farmers retained the traditional meth-
ods and, as the evidence has built up of the pollution of the water
table and rivers by these chemicals, there has been a renaissance of
organic farming in the last fifty years.
The sustainability of organic farming derives from the recycling
of organic material to maintain its fertility, just as in a natural for-
est. Modern organic composting tends to use green vegetable mat-
ter rather than dried, interleaved with layers of earth. Significant
HIDDEN NATURE