This study was presented during the conference “Production and Carbon Dynamics in Sustainable Agricultural and Forest Systems in Africa” held in September, 2010.
Swedish University of Agricultural Sciences www.slu.se Assessing multi-functionality of agroforestry systems in Western Kenya. Food security, climate change adaptation and mitigation Ingrid Öborn, Ylva Nyberg, Mattias Jonsson, Fergus L Sinclair ABSTRACT: Agricultural productivity in sub-Saharan Africa is stagnant or declining and the rural population is increasing which has resulted in land shortage and food insecurity. Increased pressure on natural resources is also increasing the vulnerability to climate change. Although Africa accounts for only 3 to 4 % of global carbon dioxide emissions, it will be among the regions of the world to be hardest hit by climate change. To be able to enhance productivity and improve the livelihood in the long-term the declining trend in soil fertility and tree cover has to be reversed and the resilience of farming systems enhanced. The overall aim of the project is to contribute this. This study focuses on carbon and nutrient fluxes and stocks, soil fertility and agricultural productivity in small-holder farming systems in Western Kenya combining crops and trees (agroforestry) with and without livestock. Field studies of fluxes and stocks of carbon and nutrients will be combined with simulation modelling at field (plot), farm and landscape scale. The study will cover a chronosequence of agroforestry farms in an area where trees have been promoted since 1995, a comparative study of farming systems with different level of integration between crops, trees and livestock, and development of a set of quick and easy field, farm and landscape level indicators of climate change adaptation potential. The research will be carried out by the Swedish University of Agricultural Sciences (SLU) and the World Agroforestry Centre (ICRAF) in collaboration with the NGO Vi Agroforestry (Vi-skogen). The newly initiated project funded by Formas and Sida includes senior scientists as well as students at PhD and MSc level. At present one PhD study and two Minor Field Studies are carried out within the project.
Transcript
Swedish University of Agricultural Scienceswww.slu.se
Assessing multi-functionality of agroforestry systems in Western Kenya. Food security, climate change adaptation and mitigation
Ingrid Öborn, Ylva Nyberg, Mattias Jonsson, Fergus L Sinclair
ABSTRACT: Agricultural productivity in sub-Saharan Africa is stagnant or declining and the rural populationis increasing which has resulted in land shortage and food insecurity. Increased pressure on naturalresources is also increasing the vulnerability to climate change. Although Africa accounts for only 3 to 4 % ofglobal carbon dioxide emissions, it will be among the regions of the world to be hardest hit by climatechange. To be able to enhance productivity and improve the livelihood in the long-term the declining trend insoil fertility and tree cover has to be reversed and the resilience of farming systems enhanced. The overallaim of the project is to contribute this.
This study focuses on carbon and nutrient fluxes and stocks, soil fertility and agricultural productivity insmall-holder farming systems in Western Kenya combining crops and trees (agroforestry) with and withoutlivestock. Field studies of fluxes and stocks of carbon and nutrients will be combined with simulationmodelling at field (plot), farm and landscape scale. The study will cover a chronosequence of agroforestryfarms in an area where trees have been promoted since 1995, a comparative study of farming systems withdifferent level of integration between crops, trees and livestock, and development of a set of quick and easyfield, farm and landscape level indicators of climate change adaptation potential.
The research will be carried out by the Swedish University of Agricultural Sciences (SLU) and the WorldAgroforestry Centre (ICRAF) in collaboration with the NGO Vi Agroforestry (Vi-skogen). The newly initiatedproject funded by Formas and Sida includes senior scientists as well as students at PhD and MSc level. Atpresent one PhD study and two Minor Field Studies are carried out within the project.
Swedish University of Agricultural Scienceswww.slu.se
Assessing multi-functionality of agroforestry systems in W Kenya
Food security, climate change adaptation and mitigation
Ingrid Öborna*, Ylva Nyberga,b, Mattias Jonssona, Fergus L Sinclairc
a Swedish University of Agricultural Sciences (SLU)*Email: [email protected]
b Vi Agroforestry, Kisumu, Kenyac World Agroforestry Centre (ICRAF), Nairobi, Kenya
Swedish University of Agricultural Scienceswww.slu.se
Outline• Multi-functionality• What is agroforestry? • Aim of the project• Study areas and research plan
Swedish University of Agricultural Scienceswww.slu.se
Ecosystem services and multi-functionality
• Multi-functional agricultural system - produce and provide multiple products and functions -food, other products and services
Swedish University of Agricultural Scienceswww.slu.se
What is agroforestry, and why?
Swedish University of Agricultural Scienceswww.slu.se
• Integration of trees with crops and/or livestock on farms and in agricultural landscapes
Agroforestry – trees on farms and in agricultural landscapes
Swedish University of Agricultural Scienceswww.slu.se
Trees and shrubs for fodder, fruit, fuel, shelter, construction, medicine, green manure, mulch etc
Swedish University of Agricultural Scienceswww.slu.se
Tree, crop and livestock products for the household and for generating income
Swedish University of Agricultural Scienceswww.slu.se
Overall aim• Agroforestry is a promoted land use system in E
Africa to increase on-farm food production and income, generate tree products and provide environmental services (e.g. Amos Wafula Wekesa, Carbon Project)
• The aim of the project is to assess and quantify some of the multiple functions and to identify potential synergies and goal conflicts at different scales.
Swedish University of Agricultural Scienceswww.slu.se
• Focus on productivity, nutrient cycling, soil fertility, carbon stocks and biological pest control in small-holder agroforestry systems, as compared to crop based systems, in different landscapes
• Identify coping strategies for climate adaptation, in particular to rainfall variability, in two contrasting areas in W Kenya
• Combine on-farm biophysical and participatory studies with simulation modelling at different scales.
The project will
Swedish University of Agricultural Scienceswww.slu.se
Swedish University of Agricultural Scienceswww.slu.se
Chronosequence
From maize to agroforestry
Tranz Nzoia (Kitale)
Swedish University of Agricultural Scienceswww.slu.se
Chronosequence• Careful selection of on-farm fie
(6 ages 0-15 years and 5 of ea age)
• Sespania and/or Calliandrahedgerow systems with maize/beans as main crops
• Representative soil samples fo bulk density and total organic- and N analyses.
• If successful – more studies w carried out on these farms (nu cycling, productivity, income, biological pest control, etc.)
Swedish University of Agricultural Scienceswww.slu.se
Expected outcomes
Quantifications of the soil C and N stocks and soil bulk density in cbased and agroforestry systems of different agesSimulations of the development of C and N stocks over time in orde compare and contrast the field estimates with model predictions (understanding effects of water, nutrient and light competition betw trees and crops).
Swedish University of Agricultural Scienceswww.slu.se
Adaptation/Coping strategies for rainfall variability
• Focus group discussions and questionnaires to identify and score strategies.
• Semi-structured interviews with local advisers
• Compare:– 2 climatic conditions (Trans Nzoia and Nyando)– Farmers receiving or not receiving agroforestry advisory services– Women and men perspectives
Swedish University of Agricultural Scienceswww.slu.se
Expected outcomes
• Understand of how climate, agroforestry advisory services and gender affect the choice of strategies and their importance
• A monitoring tool for assessment of households’ relative climate adaptation potential based on local and scientific knowledge
Swedish University of Agricultural Scienceswww.slu.se
The project is funded by Formas-Sida and SLU
Swedish University of Agricultural Scienceswww.slu.se
Overall aim To improve agricultural productivity and livelihood for small-holder farmers in the long-term the declining trend in soil fertility and tree cover has to be reversed and the resilience of farming systems enhanced. The overall aim is to contribute to this.
This study focuses on productivity, soil fertility, and carbon and nutrient fluxes and stocks, in small-holder agroforestry systems in W Kenya
Swedish University of Agricultural Scienceswww.slu.se
• Focus on productivity, nutrient cycling, soil fertility, carbon stocks and pest control in small-holder agroforestry systems
• Combine on-farm biophysical and participatory studies with simulation modelling at different scales.
Specific objectives are to:• Quantify soil carbon stocks in a chrono-sequence where trees
have been promoted since 1995• Compare nutrient cycling and soil fertility in farming systems
with different level of integration between crops, trees and livestock
• Study biological pest control in maize in agroforestry and monoculture systems in different landscapes
• Identify coping strategies for climate adaptation, in particular to rainfall variability, in two contrasting areas in W Kenya
The project will
Swedish University of Agricultural Scienceswww.slu.se
Studies planned/initiated1. Pilot study: sugarcane vs agroforestry (MFS
Gustaf Magnusson Kroon & Ida Lindell, 1. 16.40)2. Farmer adaptation/coping strategies for rainfall
variability – climate, advisory, gender (PhD)3. Soil C and N stocks, and bulk density, in a 15
(20) year chronosequence - from crop (maize) to agroforestry (mixed tree –crop) system (PhD)
4. Farm gate and field plot nutrient and carbonbalances
Swedish University of Agricultural Scienceswww.slu.se
Field, farm and landscape scale -modelling
• The WaNuLCas model (van Noordwijk et al, 2004) will be parameterised and used to simulate the development over time of biomass and soil C and nutrient in the agroforestry plots in the chrono-sequence. Explore more/other options, O Andrén et al?
• In the farm level study the NUANCES framework will be used to explore the effects on C and nutrient cycling of increased diversity/complexity starting with a maize-bean rotation (Wijk et al, 2009). Possible collaborations? S Dahlin et al?
• For the landscape modelling, Polyscape will be used for exploring synergies and trade-offs amongst the impacts of trees on different ecosystem services depending on where and to what extent trees are established (Pagellaet al., 2009). Explore links and joint interests with G Nyberg et al?
Swedish University of Agricultural Scienceswww.slu.se
