Tony Bartlett is Forestry Research Program Manager with the Australian Centre for International Agricultural Research (ACIAR). A version of this story was originally posted on the ACIAR website. ACIAR will host a session titled Equitable development: Improving livelihood benefits for smallholders in the forestry value chain at the Forests Asia Summit in Jakarta on May 5 and 6. Follow @ACIARAustralia on Twitter
Smallholder farmers in the Luang Prabang region of northern Laos have planted at least 25,000 ha (61,750 acres) of teak over the past 20 years, and current government policies support continued expansion.
In most cases, farmers plant up to 2,500 trees per ha and farm the land around the trees for three to four years until the tree canopy blocks out sunlight and inhibits growth of plants growing below.
This can make life difficult for farmers who don’t have enough land to grow crops somewhere else while they wait for their teak trees mature to a size of high value.
Due to the lack of teak markets for selling small logs, farmers are reluctant to thin out densely-planted teak forests, even though this maximizes growth and improves the quality of the remaining trees. So, how can research help farmers overcome these issues?
ACIAR’s teak research in Laos, led by the University of Queensland in Brisbane, Australia, studies the growth of teak at different initial stockings (concentrations of trees planted) through the use of “Nelder Wheel” trials.
In these trials, teak is planted in rows along the “spokes” of a wheel shape in the field. Because the distance between rows increases along the rows from the center of the trial, there are different planting densities at each point along the spoke.
By monitoring these trials over a 5 to 10 year period, you can determine the average growth of teak at different stockings (from 100 to 2,500 trees per ha).
After five years, the research shows that the best rate to plant and maximise tree width and height is 600 trees per ha. This is a fraction (a third or less) of the number of trees traditionally grown per hectare.
This approach gives farmers the option of growing crops in the extra space between trees. In 2012, we tested the growth-rate of crops including maize, pigeon pea, soybean and cassava under different teak spacings.
The crops were planted in the spokes of a Nelder Wheel trial and early results indicate that they can all be grown very successfully when the five-year-old teak stocking is 600 or less per hectare. This system would have a triple benefit to farmers: the trees grow faster to high-value size, crops can continue to be planted between maturing trees, and non-commercial tree thinning is no longer needed.
In the small village of Ban Phonsavanh, I met local farmer Khamsone Phonsavanh who has worked with project staff to develop an agroforestry system.
He plants paired rows of teak, with banana, broom bush and upland rice planted in the spacing between the paired rows. He told me he is happy with the four-year-old teak trees and knows that they will provide him with a good return in the future, and in the meantime he can still earn some income from his other crops.
More information: ACIAR project FST/2004/057 Enhancing on-farm incomes through improved silvicultural management of teak and paper mulberry plantations in Luang Prabang Province of Lao PDR Led by University of Queensland, Australia. Other partners include: Salwood Asia Pacific Pty Ltd, Australia Luang Prabang Agriculture and Forestry College, Laos National Agriculture and Forestry Research Institute, Laos Souphanavong University, Laos ACIAR’s forestry research in Lao PDR (2011 bulletin) Lao PDR research strategy.