December 11, 2012
Dar
es Salaam – Growing coffee and banana together not only generates more
income for small-holder farmers, compared to growing either crop alone, but it
can also help coffee production to better cope with the effects of climate
change, a recent study has shown.
The study, which sought to understand the
potential impact of climate change on coffee-based livelihoods in the East
African highlands, found that the areas suitable for growing Arabica coffee
will drastically decrease in the future leading to losses in the region that
may exceed US$100 million annually. This is not only a threat to the countries’
foreign revenue, but it also puts at risk the livelihoods of millions of
small-holder farmers depending on the crop.
The researchers from the International
Institute of Tropical Agriculture (IITA) in collaboration with those from the
Colombian-based International Center for Tropical Agriculture (CIAT), used
climate models and climate analogues to predict the impact of climate change on
coffee production. The researchers walked down the slopes of Rwenzori
Mountains, in Uganda, where the lower one goes, the temperatures get
progressively warmer and drought stress becomes a more serious problem—similar
to walking into a “future climate”.
The approach illustrated that areas below
1300 m may well become completely unsuitable for Arabica coffee production. In
areas between 1300-1700 m, coffee will be severely affected if current farming
practices that use traditional varieties and make limited use of water
conservation and shade technologies remain unchanged.
In Uganda, coffee is the most important
export crop generating approximately 20% of the foreign exchange earnings.
One-third of the coffee export value is from Arabica coffee, which requires a
particularly cool tropical climate that is only found at higher altitudes,
generally above 1400 m. Arabica is therefore very sensitive to a rise in
temperature induced by climate change. Coffee is also among the top three
commodity exports in Ethiopia, Rwanda, Burundi, and Tanzania.
Shade provided by shade trees or banana can
help coffee to cope with the warmer climate and with drought shocks. Research
has shown that shade can reduce the temperature in the understory plants by up
to 2º C or more. Past research by IITA also showed that growing coffee and
banana together increased the farmers’ income – the coffee yield remained the
same despite creating room for the banana and the farmer gained additional
income from selling the banana. This study strengthens the case for growing
coffee and banana together as it provides both short- and long- term benefits
to farmers.
“Strategies to help farmers cope with climate
change will often be more successful if farmers are also able to see the immediate
benefit of their investment. By growing banana and coffee, in a year’s time,
the farmers will be earning extra money from selling banana,” says Dr Piet van
Asten, an agronomist with IITA based in Uganda and one of the researchers. “And
if coffee fails, then bananas will still provide the farmer with food and
income. It is a perfect win-win situation for both crops and the farmers.”
The researchers also interviewed farmers in
the region who said the climate was already changing—the droughts were becoming
longer, rainfall was becoming more erratic, and the rainy seasons were becoming
shorter. This negatively affected the flowering of coffee and reduced the sizes
of the berries.
The farmers had also observed that pests and
diseases such as leaf miners, coffee berry borers, mealy bugs, and leaf rust
were on the rise. However, the study found that leaf rust incidences were 50%
lower in coffee that was shaded by banana compared to the unshaded plants.
The findings are supported by another study
by Alessandro Craparo from the University of Witwatersrand with support from
IITA, CIAT, and CGIAR Consortium Program on Climate Change and Agricultural
Food Security (CCAFS) and the Tanzania Coffee Research Institute (TaCRI) that
is looking at the influence and impact of climate change variability on Arabica
coffee in the Mt Kilimanjaro area. It found that every minimum temperature
increase of 1º C would lead to a yield loss of almost 100 kg/ha, representing
20% of the current yield.
The only drawback to adding shade to coffee
is that it demands more nutrients and farmers will have to invest in
maintaining the soil fertility.
“The downside of adding shade or shade crops
to a coffee system is that it increases competition among the different plants
for water, nutrients, and light. This competition needs to be managed by using
good agronomic practices such as integrating fertilizers and organic nutrient
inputs, appropriate plant density and canopy management, and good soil and
water conservation practices to adapt successfully to climate change,” Dr Van
Asten said.
The studies on impact of climate change on
coffee systems in Uganda received support from Climate Change, Agriculture and
Food Security (CCAFS), the Consortium for Improving Agriculture-based
Livelihoods in Central Africa (CIALCA) project, Oxfam, USAID, Wageningen
University (WUR), and a wide range of coffee sector partners in the region.
The studies on impact of climate change on coffee
systems in Uganda received support from Climate Change, Agriculture and Food
Security (CCAFS), the Consortium for Improving Agriculture-based Livelihoods in
Central Africa (CIALCA) project, Oxfam, USAID, Wageningen University (WUR), and
a wide range of coffee sector partners in the region.
###
For more information, please contact:
Catherine Njuguna (c.njuguna@cgiar.org)
IITA East Africa Hub
Dar es Salaam, Tanzania
IITA East Africa Hub
Dar es Salaam, Tanzania
Oliver
Jeffrey, O.Jeffrey@cgiar.org
IITA hub for Southern Africa
Lusaka, Zambia
IITA hub for Southern Africa
Lusaka, Zambia
Godwin
Atser g.atser@cgiar.org
IITA-hub for West Africa
Ibadan, Nigeria
IITA-hub for West Africa
Ibadan, Nigeria