Financial Times

Coconut 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.

Catalysts and Ratalysts
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.

Analogies 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.

In 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 through photosynthesis.

In 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).

The 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.

The 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'!

Re-Greening Sri Lanka
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).

Thus continuing to provide the shade, and all the environmental and social benefits for which this increased ground coverage of green matter is well known.

Trials 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 in growing.

Continuing 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.

Proven 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.

This 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.

A 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.

The 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.

'Gasifiers'
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.

A '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.

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