Using ecological niche modelling to guide farmers and the Government of Nepal.
Banana is a high-value agricultural product and a major fruit in Nepal in terms of the potential growing area, production, and domestic consumption. It is currently grown in 68 of Nepal’s 75 districts, and the total productive area of banana plantations in 2012/2013 was 11,864 ha, with a total production of about 182,005 tonnes.
Although there is great potential for banana production in Nepal, there are few commercial banana plantations and current productivity is low. According to the Ministry of Agriculture, the current average productivity is 13.2 tonnes per hectare, with maximum yields reaching up to 20 tonnes per hectare.
Demand for bananas in Nepal currently exceeds the total national production. According to the Trade and Export Promotion Centre of the Government of Nepal, in 2011/2012 Nepal imported 27,878 tonnes of bananas from India to meet the domestic demand, particularly in urban and peri-urban areas.
The project 'Spatial Modelling of Climate Change Impacts on Two Major Cash Crops in Nepal' implemented by HELVETAS Swiss Intercooperation in collaboration with the Centre for Mountain Ecosystem Studies at the Kunming Institute of Botany and funded by ICIMOD under its SERVIR-Himalaya Initiative, developed a model that projected the impacts of bioclimatic conditions on the banana crop. The project provided interactive maps of suitable crop zones through a knowledge platform (http://landscapeportal.org) to improve understanding of the potential impacts of climate change on high-value cash crops in Nepal for policy dialogue and sub-sector planning. The project incorporated field work including farmer surveys, mapping of current banana plantation areas, and suitability modelling using bioclimatic, environmental stratification, land use, and geographical data. Altogether 105 farmers growing banana in two districts – Kavrepalanchok and Chitwan – were interviewed for the project.
In Chitwan District, banana is widely commercialized and the number of commercial plantations is rising, and current plantations are expanding, in the area. Most of the district is climatically suitable for growing banana, and hence the production potential is high. Farmers have adopted crop rotation that helps minimize insect and disease infestation: banana is grown for five to six years and then cleared for rice, maize, and mustard for one to two years.
In Kavrepalanchok District, banana is not widely commercialized. Farmers primarily plant banana for their own consumption or to sell at small-scale roadside markets. Although the low-altitude areas of Kavre District are climatically suitable for growing banana, niche modelling has identified new areas in the southern, eastern, and northern parts of the district that have potential for commercial plantation. “If necessary training for farmers and good knowledge sharing on proper variety of the crop could be assured, banana cultivation could be successfully commercialized in Kavrepalanchok District”, says Dr Sailesh Ranjitkar, the project’s lead researcher.
In addition to visible problems, like crop pests and a lack of proper market and crop information, there is a large silent threat approaching. Researchers around the world have already revealed the severe impact of climate change on agriculture, which includes a shift in the zone suitable for cultivating banana.
Dr Robert Zomer, Senior Landscape Ecologist at World Agroforestry Centre (ICRAF) and GIS backstop of this project, says, "Climate change is a slowly approaching disaster that will hit most structures and systems in the future. The agricultural system is no exception”. He further added, “There will be noteworthy change within environmental zones, which are equivalent to agro-ecological zones. Existing strata will decline while new strata will invade the landscape, and such changes in the environmental stratification will change the suitable production zone for agricultural crops” (Table 1).
Global environmental zone
|Current occupied %||Projected change in future %|
|Alpine||Extremely cold and wet 1||ECW1||0.04||-71.39|
|Alpine||Extremely cold and wet 2||ECW2||4.29||-60.92|
|Alpine||Cold and wet||CW||1.33||-69.35|
|Alpine||Extremely cold and mesic||ECM||13.17||-4.64|
|Alpine||Cold and mesic||CM||7.60||10.76|
|Cool temperate||Cool temperate and dry||CTD||1.41||-13.12|
|Cool temperate||Cool temperate and moist||CTM||5.92||-18.06|
|Warm temperate||Warm temperate and mesic||WTM||20.11||-9.38|
|Sub-tropical||Hot and mesic||HM||22.18||31.48|
|Drylands||Hot and dry||HD||13.00||-23.12|
|Drylands||Extremely hot and xeric||EHX||0.00||100.00|
|Tropical||Extremely hot and moist||EHM||10.95||12.06|
Map: Projected changes in suitable banana production zones
The results of the project were discussed with stakeholders from Nepal’s Ministry of Agricultural Development and Ministry of Forests and Soil Conservation, research institutes, non-governmental organizations, and farmers’ representatives during a consultation workshop on ’Present Status and Future Prospects of Agroforestry in Nepal’ in March 2015. Out of this discussion, a strategy for developing a banana-based agroforestry system, particularly with coffee, was proposed as an option for sustainable agriculture in banana and coffee-suitable zones identified by the project.
During the workshop, the need for a policy to promote agroforestry to facilitate food and nutritional security was emphasized by the Minister of Agricultural Development, who said, “Nepal needs an dedicated policy to accelerate efforts to mainstream agroforestry. In consultation with the Minister of Forests and Soil Conservation, I assure you this important development will receive our full support”.
The study identified suitable zones for planting banana in the future and promoted a more sustainable farming practice that included a mixed banana agroforestry system. The final research outputs are available on the geoportal of the World Agroforestry Centre GeoScience Lab (http://landscapeportal.org/). Users can easily search uploaded layers, and project information and layer descriptions can be viewed in the metadata. Each layer is provided with “create a map” option which can use to prepare map, overlay several layers and view current rainfall information for each grid using option in the tool button. This site is user friendly, and maps can be prepared according to user needs using the project’s research results.