Extensive literature on trials shows this biomass species grows better in drier climates

Dear Editor,

Although Go-Invest and the Ministries of Agriculture and of Tourism, Industry and Commerce do not seem to have the information, I was pleased that the family owners of Pinnacle Green Resources (Guyana) Inc. have provided some data about the company ownership and its state of knowledge of production of plantation woody biomass (Stabroek News, 22 October 2014, ‘Pinnacle Green Resources’ research has shown that this biomass plant is suitable for local climate, Pomeroon soils’).  So we now know that this is a family business – the Beekay Group – first registered in 1966 and mainly engaged in iron and steel work in India.  It is not clear what are the actual businesses of the daughter company Pinnacle Commodities (Asia) Limited registered in Hong Kong in 2007, and the grand-daughter company Pinnacle Green Resources Pte. Ltd. (Singapore) formed in 2012.  The great-grand-daughter company Pinnacle Green Resources (Guyana) Inc. was registered in 2013 to process wood and crop waste in Guyana into pellets for biomass heating in Sweden.  It is not clear that a market survey or economic study has been made, and it is difficult to see how pellets from Guyana could compete with pellets from the plantations and forests in the southeastern states of the USA for biomass heating in Europe, given the probably much lower production costs in the USA and the certainly cheaper shipping costs: see  http://www. globaltimber.org.uk/guyana.htm.

As regards the production of economically profitable woody biomass from plantations of ‘jumbie bean’ (Leucaena leucocephala), the literature cited by the Pinnacle company is mostly to do with growing the shrubby or ‘common’ species and varieties of Leucaena as forage for cattle.  Those are not the species and arborescent ‘giant’ types which are grown elsewhere for wood; see Colin Hughes (1998, pages 19-21) ‘The genus Leucaena: a genetic resources handbook’, Tropical Forestry Papers 37, Oxford Forestry Institute.  As regards matching of Leucaena to the soils of Pomeroon, the Pinnacle company relies on a couple of CARDI papers from August 2002 about an agroforestry trial from 1997-2000 on Kasarama loamy sand in the Intermediate Savannas.  As these papers note, the soils are acidic and of low fertility.  The Leucaena was grown from seed but the variety and seed origin are not described.  The Leucaena produced much less leafy biomass for crop mulching than the second woody species on trial, Gliricidia sepium, which was grown from stakes.  The CARDI staff noted that ‘The Leucaena trees were treated with liming material, because it is well known that Leucaena requires more alkaline conditions’.  The CARDI trial was on the effects of mulching sorghum, cowpea and maize with tree leaves compared with synthetic fertilizer from a sack, so we do not know how much woody biomass was produced.  However, the trial used between three and five times greater weight of Gliricidia leaves than Leucaena leaves, apparently because the Gliricidia stakes grew much better than the Leucaena seedlings, in spite of the liming.

The Pinnacle company also references an introductory agroforestry handbook written by Thorwald Geuze and Pauline van den Ende in London for VSO volunteers and published by IICA in 1996, in which Leucaena is described in three pages (out of 96). It seems clear that the Pinnacle company is unfamiliar with the extensive literature on international and multi-country comparative trials of Leucaena varieties, species and hybrids.  Some of these comparisons also include other multipurpose, nitrogen-fixing, dry-zone hardwoods.  Guyana did not participate in these trials.  Lascano and colleagues summarized findings for  ‘Leucaena in central and south America’ on pages 152-158 of the compilation edited by Shelton, Piggin and Brewbaker in 1994 (‘Leucaena – opportunities and limitations: proceedings of a workshop held in Bogor, Indonesia 24-29 January 1994’,  ACIAR Proceedings number 57).  Lascano’s map on page 156 shows ‘Areas in South America with potential to grow leucaena’ but Guyana is a blank except possibly the south Rupununi savannas.  What this and another map show clearly is that the growth potential is in areas with drier climates: ‘Leucaena can grow well in a wide variety of environments in the tropics and sub-tropics, but it has some well-defined limitations, such as acid soils with low base saturation, soils with poor drainage and environments with low temperature.  A multi-locational trial in Costa Rica showed that leucaena performed better in sites with a well defined dry season’.  These findings concur with the larger review of  literature on soil-climate-species matching by Colin Hughes, mentioned above.

In summary, even if production costs were very low, the shipping costs bearable and the market still available, growing an undefined variety of Leucaena leucocephala in Pomeroon for wood pellets to be burned for heating in Sweden does not look like a business-minded investment.

Yours faithfully,
Janette Bulkan

 

 

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