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Today is :
Archives (2003) : Soils
Growing money
on trees
by Likha
Cuevas |
January-March
2003
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In the Philippines, it's not surprising to
see mountains and hills that look like green or yellow-green
mounds. Some are entirely green, some have only patches of
greens. Upon closer inspection, the green expanse is due to
cogon grass (Imperata cylindrica). More often than not, trees
are sparse, or not present at all.
Usually, mountain grasslands are products of
kaingin or slash-and-burn cultivation. If the forest land
is frequently burned or grazed, pyrophytic (regenerates after
fire) grasses like cogon invades and replaces the formerly
dominant woody plants and trees in the area. Easily dispersed
by wind, Imperata flourishes with lots of sunshine and can
tolerate poor soil in erosion-prone areas.
Grasslands
Grasslands are for grazing or cropping using traditional farming
and/or shifting cultivation. Studies show that over-cultivated
upland areas result to extreme soil loss which threatens the
sustainable productivity of the upland.
According to Dr. Canesio D. Predo of Leyte State
University (LSU) and Dr. Herminia A. Francisco of UP Los Baños
(UPLB), "the Philippine government is concerned with
rehabilitating vast areas of grasslands in the country through
reforestation and other tree-based plantation establishment,
including agroforestry." This land use system can increase
income and improve water supply, carbon sequestration, reduce
soil erosion, and enhance biodiversity.
Based on this premise, the team conducted a
survey to evaluate the nvironmental and economic benefits
of alternative land use options in some grasslands in Claveria,
Misamis Oriental in Mindanao.
Results indicate the benefits from carbon sequestration
in tree-based farming systems. "Carbon sequestration,"
Predo and Francisco explained, "refers to the process
by which trees use carbon dioxide that otherwise could pollute
the atmosphere." By reducing carbon dioxide in the atmosphere,
trees can mitigate global warming or climate change.
Predo and Francisco also clarified that it is
important to provide farmers with incentives to encourage
them to adopt tree-based farming.
Alternative land-use
systems
The study used six models of land use systems to rejuvenate
Imperata grasslands. These were:
- IMPLUS Imperata land use for animal pasture or grazing
system
- FPLUS farmers' current practice of annual maize cropping
system (100% of the area devoted to corn); soil is cultivated
before planting corn; inorganic fertilizers were applied
- TIMPLUS timber trees with Imperata for animal pasture
or silvopastoral system; 85% is allocated to Imperata while
15% is planted to trees
- TCLUS timber trees planted in hedgerows with annual maize
cropping system at the alley areas; 85% is devoted to corn
and 15% to timber
- TCSFLUS social forestry model of agroforestry system wherein
the bigger areas are devoted to timber trees in hedgerows
with annual maize cropping at the alley areas; 40% devoted
to timber while 40% is devoted to corn
- TPLUS timber plantation land use system
The tree species used were the Gmelina arborea
(non-nitrogen fixing tree) and Acacia mangium (nitrogen-fixing
tree). In all of the systems, 60% of the tree component is
Gmelina arborea and 40% Acacia mangium. In the TCSFLUS system,
the tree components were equally distributed (20%-20%).
Results showed that it was profitable to retain
Imperata grassland for animal grazing purposes; however, it
was not the most efficient type of land use," the research
team said. "Conversion of Imperata grassland into tree-based
systems were more efficient than other land use systems."
TPLUS (timber plantation system) was the most
efficient land use system among the tree-based systems because
of the high value of harvested timber, lower predicted soil
loss, and high level of soil nutrients sustained. From data
collected over 20 years, the researchers concluded that TPLUS
system had the highest NPV over 20 years, followed by TCSFLUS
system. Losses in the FPLUS system increased due to lowering
yields from high soil erosion.
If tree-based systems are profitable, why do
farmers insist on the traditional farming system (FPLUS)?
The researchers explained that smallholder farmers do not
want to risk their income from crops with the projected income
from trees.
Benefits from
trees
So how will farmers adopt tree-based farming if it's too risky
and the benefits are not immediate? The study showed the potential
of the TCLUS system where farmers can get income from corn
while waiting for timber to grow. Predo and Francisco projected
that farmers can get their money back from timber in seven
to ten years.
There are also environmental benefits of tree-based
systems. Soil erosion can be reduced by 20% - 91% compared
to farmers' practice, with soil loss up to 75%.
Tree-based farming was introduced by the World
Agroforestry Centre (ICRAF) in Mindanao in cooperation with
LGUs, farmers associations, and other government institutions.
In the Visayas, ICRAF, and LSU/Cornell University are involved.
"In Northern Luzon, farmers are planting trees because
of the demand for wood by a private company," the team
reported.
"Farmers like tree-based farming systems.
It makes the soil fertile, the environment cooler, and it
increases their income," Predo and Francisco replied.
The farmers also said this system is a good investment for
their children. However, some farmers are hesitant to adopt
this system because of small farm size, lack of capital, and
lack of access to planting materials.
But with proper policies, good governance, and
support, it's not impossible for farmers to plant trees for
a better future.
References: Predo, C.D. and Francisco, H.A.
Bioeconomic Analysis of Land Use Options for Grassland Areas
in Claveria, Misamis Oriental. 2002; Masipiqueña, A.B.,
Person, G.A. and Snelder, D.J. The Use of Fire in Northeastern
Luzon (Philippines): Conflicting Views of Local People, Scientists,
and Government Officials. Cagayan Valley Program for Environment
and Development. http://www.lucy.ukc.au.uk/Rainforest/Workingpaperspublic/Fire/fire_9.html;
Mueller-Dombois, D. Biological Invasion and Fire in Tropical
Biomes. January 2002. University of Hawaii. http://www.nif.gov/joint_fire_sci/invasive%20publications/
Hrs_22pr_10_112_121_c.pdf 
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