Project leader: Erik Karltun
Sub-project 1: Soil and water management in agricultural production – participatory management of natural resources for intensified production
Principal investigator at SLU: Erik Karltun, Department of Soil and Environment
Popular summary
Higher crop production needs higher nutrient input and more available water. However, fertilizer is expensive and not always available and the use of available water sometimes sub-optimal. This is problematic since production needs to be intensified (higher crop yield per ha) due to population increase. This project will contribute to an improved food security by development of soil and water management options that will improve nutrient use efficiency (higher harvest/added nutrient) and water use efficiency (higher harvest/unit available water). The relevance of the research is improved by addressing both socio-economic as well as biogeophysical limitations and by involving the farmers through participation in formulation of research priorities and evaluation of results.
The two overall aims for our research are (1) to identify the factors that prevent farmers in the Ethiopian highlands from a sustainable management of their soil and water resources and (2) together with the farmers test management options that are affordable and locally acceptable. In this work we work inter-disciplinary and with participatory methods.
We will investigate why some farmers adopt new plant nutrient management methods while others do not in order to identify the bottlenecks that prevent farmers from adoption. We will also look at how traditional institutions and networks can be used to disseminate information and knowledge about sustainable crop management. We will also continue the work with on-farm experiments that we have established together with the farmers.
One of the most important questions we want to answer is to try to explain why a combination of fertilizer and compost (each given as half-dose) consistently gives higher yields for several crops than fertilization with mineral fertilizers or compost alone. Water availability is a key factor in crop production. We will in the project also study how management of water can be improved both at landscape and field scale.
During the project we will arrange different types of dissemination towards stakholders at various levels (farmers, extensionists, policy makers). We will also arrange a scientific workshop on how climate change influences food security and water access in Ethiopia.
Our project builds on an on-going collaboration with Wondo Genet College of Forestry and Natural Resources at Hawassa University and the Department of Department of Geography and Environmental Studies and the Institute for Ethiopian Studies at Addis Ababa University. Participating departments from SLU is the Dept. of Soil and Environment, Dept. of Water and Environment and Dept. of Urban and Rural Development. We will support on-going PhD and MSc thesis projects with support to fieldwork and analyses.
Questions about the project can be directed to Erik Karltun (erik.karltun@slu.se).
Sub-project 2: Evaluating organic matter dynamics, soybean production, value-addition and Striga weed suppression in Integrated Soil Fertility Management systems - towards improved productivity, sustainability, and livelihoods of smallholder farmers in Kenya and Uganda
Principal investigator at SLU: Kristina Röing de Nowina, Department of Soil and Environment
Popular summary
Researchers at the Institution of Soil and Environment will together with collaborators from CIAT-TSBF (www.cgiar.ciat.org) work together within the theme “Diversified and sustainable farming systems – effective resource utilization and soil fertility” to improve the terms of production for smallholder farmers through an increased soil fertility.
Improved soil fertility can be attained by increasing the content of soil organic matter with addition of crop residues in different forms (fresh or degraded) and with different origin (manure, bio-char etc). In production systems including for example soybean, an increase in soil fertility has been documented as well as a decrease of the seed bank of the weed Striga hermonthica, which can causes severe yield losses.
Students from SLU and universities in Kenya and Uganda will, together with researchers and smallholder farmers, analyze which system improvements are possible, through field trials, variety evaluations, greenhouse experiments, modeling and participatory methods.
In collaboration with the African Network for Soil Fertility (AfNet) a scientific conference will be arranged during 2012.
Sub-project 3: Multifunctionality of agroforestry systems; can introduction of trees and crops contribute to enhance agricultural productivity, resource utilisation and livelihoods for smallholder farmers? A quantitative approach
Principal investigator at SLU: Ingrid Öborn, Department of Crop Production Ecology
Popular summary
Agricultural production in sub-Saharan Africa is stagnant or declining while there is a population growth. This has resulted in shortage of land and food insecurity in many parts of East Africa. . Increased pressure on natural resources, including deforestation, is also increasing the vulnerability of small holder farmers to climate change, often resulting in rainfall variability and water scarcity. Low input of mineral fertiliser and manure has led to nutrient mining and reduced soil fertility.
In order to enhance the productivity and improve the livelihood in the long run, the declining trends in soil fertility and tree cover need to be reversed and the resilience of the farming systems to climate variability and other stress factors enhanced. More trees on farms and in agricultural landscapes are needed to produce firewood, timber, fodder, fruit, etc. and to deal with environmental problems caused by deforestation. There is an expressed interest in farming systems with intercropping of trees and crops, in combination with livestock for eggs, milk and meat, so called agroforestry systems.
The main research question in this project is: Can integration of trees and crops, and often livestock, contribute to enhance agricultural productivity and resource utilization, and contribute to improved living conditions for smallholders?
We are using a quantitative approach to assess the productivity and multifunctionality of agroforestry systems at different scales applying available modelling tools. Data collected in ongoing projects will be used as a base together with additional data gathered within this project. The aim is to quantify the biomass production, carbon storage and nutrient flows on field (field plot), farm and landscape level in some areas in western Kenya with different soils, climates and types of agroforestry systems. At the field scale, the WaNuLCAS (the Water, Nutrient and Light Capture in Agroforestry Systems) model that includes competition between trees and crops for light, nutrients and water will be applied. Different tree species (native and exotic) will be selected and the competition between tress (of different age) and maize will be studied. At farm scale the NUANCES framework (Nutrient Use in ANimal and Cropping Systems - Efficiency and Scales) will be used to study flows of nutrients and other resources on farms with increasing complexity; crops, crops and trees, crops and livestock, crops and tress and livestock. At the landscape level, the GIS-based model Polyscape tool will be used to study the synergies and trade-offs between the trees, agricultural productivity and other ecosystem services (water and sediment flows, contiguous habitat, development of carbon storage).
The work builds on established partnerships and networks, and will be linked to ongoing research and PhD projects. The project involves researchers and students from Sweden and Kenya, and it aims to develop good cooperation and communication between research, education and extension. During the project, workshops will be held and we will be involved in different types of capacity building including courses and training programs. In addition to scientific publications and student theses, the project will contribute to produce materials that can be used by advisors, teachers and other stakeholder groups.
Sub-project 4: Soil carbon, water infiltration and root competition; implications for management in African cropping and agroforestry systems
Principal investigator at SLU: Gert Nyberg, Department of Forest Ecology and Management
Popular summary
Increasing soil carbon and the possibility for water to infiltrate into the soil is key to improve agricultural productivity in degraded and erosion prone agricultural systems as in the Nyando basin. To understand competition and/or ameliorative effects/synergies between trees and crops are fundamental in management of integrated agroforestry systems. These issues are also very relevant in a regional and global perspective for e.g. carbon sequestration, climate change and water quality.
The project consists of two parts, both with the objective to better understand and improve agriculture and food production.
- To study changes over time in soil carbon content and the infiltration rates of water in different rehabilitation and agroforestry measures (exclusion of grazers and planting along contours; woodlots planted on small farms; erosion control by terassing) in Western Kenya.
- To quantify competition between crops and trees in agroforestry systems through the analyses of isotope ratios of respired CO2 in Ethiopia and Kenya.
Both parts are extensions in time and/or in scope (geographical or methodological) of ongoing research projects with different funding. The project is in cooperation with ICRAF, TSBF and Wondo Genet College of Forestry, Ethiopia. It is part of the main research theme Diversified and sustainable cropping systems – efficient use of resources and soil fertility.