growing with Gliricidia for fertility
By Ray Wijewardene, Chancellor of the Moratuwa University
A story which some of us may recall from our school days relates
to a unique business set up by a cat farmer (he sold the fur of
the Angora cat which was in demand in Europe during the early-nineteen-hundreds)
who also established, next door, a rat farm. He fed the cats with
the rats, and the rats with the (carcasses of the) cats, and his
business sold the furs.
The common dictionary defines a 'catalyst' as 'a substance
which assists a chemical reaction without taking part in it. Chemistry
books go further to explain that the presence of the correct catalyst
often helps accelerate a chemical reaction without itself changing
from not 'appearing' to taking part in it.
currently prevail with the story of the cat and rat farms in which
the presence of the latter 'ratalysed' the production of fur; although
the rat and cat must both have changed form during the process.
It still ensured the farmer's output of Angora fur with minimal
costs for production thereof. The fur, (largely an 'oxy-hydro-carbon',)
came mostly from the air!In the sunny tropics, coconut farmers are
blessed with a 'ratalyst' in the form of the nitrogen-fixing Gliricida
tree, which when systematically grown in avenues between the lines
of coconut palms provides a major source of the nitrogen fertility
needed by the coconut palm for production of coconuts.
fact, data from research at the Coconut Research Institute conducted
over the past several decades has revealed that just 50 kilograms
of foliage from the Gliricidia (leaf and tender stems, alone) can
provide, 'naturally', all the coconut palm's annual requirement
of nitrogen (equivalent to 800 gms of urea. Otherwise the most expensive
of imported chemical fertilizers were used). This, in addition to
supplying over half the palm's annual requirement of phosphate (Rock-Phosphate)
and of magnesium (dolomitic limestone) and of potassium (Muriate
of Potash). Nitrogen is a component usefully supplied throughout
the year by nitrogen fixing plants such as Gliricidia from the atmosphere
addition, the pruned or lopped branches of the gliricidia tree provide
an equal weight of fuel-wood (now termed SGF or Sustainably-Grown-Fuelwood)
which currently fetches an ex-farm price of Rs. 1.50 per kilogram,
for supply as process-fuel to millers (DC and oil millers) and factories
which themselves now claim a saving of over 65% in the price paid
for fuel (hitherto furnace-oil or 'dhara' - wild-timber from forests).
chipped wood is 'gassified' by a simple and proven technology which
provides a gas mixture for combustion which is virtually smoke-less
and pollution free! These remarkable fuel-wood benefits now extend
to production on coconut plantations, and in the coconut-growing
areas, of 'home-grown' electricity to meet their on-farm requirements
of lighting for farm-houses and cottages, as well as for the power
needed for irrigation pumps.
pumps are an essential component of 'drip-irrigation' systems, recently
introduced to combat the effect of drought which have increasingly
affected coconut-growers over the past several decades. The Gliricidia
tree thus sustainably, year after year, decade after decade, 'fixes'
both atmospheric nitrogen in its foliage and roots, as well as carbon
and 'woody-matter' in its branches from the carbon-dioxide naturally
present in the air. By showing the potential for small decentralized
electricity generation, this is real 'decentralisation of power'!
All this without affecting the continuing growth of the
Gliricidia trees, (the 'ratalyst' in this instance) which - if at
all - appear to benefit from their systematic pruning (lopping).
continuing to provide the shade, and all the environmental and social
benefits for which this increased ground coverage of green matter
is well known.
by the BEASL (Bio-Energy-Association-of Sri Lanka) all over the
country, also in association with the universities and departments
of forestry and agriculture in much of the 'dry-zone' have demonstrated
the remarkably 'sustained' production capability of such fuel-wood
plantations even where other commercial tree crops have difficulty
research by agronomists at the CRI has been devoted to optimising
the plant-spacing in the rows of Gliricidia in the avenues between
lines of coconut palms to meet the needs of both fertility for the
palms as well as fuel-wood which now becomes a major source of supplementary
income for the coconut farmer.
incomes for the coconut grower from this supplementary source have
been in the order of Rs. 6,000 per acre per year from a sale of
the (approx. 5 tonnes of) gliricidia loppings alone.
apart from the savings of over 50% in the costs for fertilizer amounting
to over Rs.30 per palm or about Rs.1,800 per acre, a useful supplement
to the Rs.20,000 or so which he earns through sale from an acre
of coconuts alone.
unique service also extends to the DC/Oil miller as logical partner
to the coconut grower. The coconut plantation not only becomes a
source of raw material the coconut to the miller, but also an immediate
supplier of fuel-wood for processing (drying) of the coconut produce.
miller has hitherto had to depend on diesel/furnace-oil for firing
the boilers for his DC-dryer … now supplied at ever increasing
costs from the imported petroleum…. Or for 'dhara' felled
from non-sustainable, dry-zone, forests, and from now dwindling
sources of rubber-wood.
Proven results from the several 'gasifiers' established
in the coconut-growing areas show a reduction in fuel-costs by over
60% over fuel-oils thus greatly contributing to reducing the costs
for production of the miller and enabling him to be more competitive
on the world markets to which he supplies the processed produce.
'win-win' situation for both coconut producer and coconut processor…
usefully 'ratalysed' by intervention of the multiple environmental
and economic benefits of the Gliricidia tree.