Shrubs and trees to enhance agroecosystem productivity and counter land degradation in semi-arid West Africa
Does Piliostigma-based mulch from in situ vegetation result in increased sorghum and cowpea yield?
Phillipe Belliard completed his internship for his BSc in Plant Sciences at Wageningen University within the WASSA project in October and November 2014. He studied the effects of woody mulch on yields in a farmer-led experiment in Yilou, Burkina Faso. These are partial results from a long-term experiment that started in 2013.
Woody amendments: what availability at village scale?
Gaelle Feur defended her MSc thesis for the Master of Organic Agriculture (MOA) at Wageningen University in April 2015. She intended to answer the following research question (in parenthesis the hypotheses for each).
1. What is the species composition at the landscape level in Yilou? (Hyp 1:It is assumed that there are distinct vegetation types across the landscape in Yilou which are related to a diversity of soil classes)
2. What is the available standing woody biomass at the landscape level in Yilou? (Hyp 2: It is assumed that vegetation composition and its corresponding biomass quantity are related to each other ( more diversity= more biomass)
3. What is the potential standing woody biomass available for soil amendment? (Hyp 3: It is assumed that woody biomass for soil amendment use concerns mostly shrub-shaped species and that the available biomass is distributed unevenly across the landscape)
In the following link you may take a look at her Power Point presentation: Thesis presentation_Gaelle Feur_March 2015
Pilot test on farmer fields: the effect of woody amendments on sorghum yields
Pilot tests have been installed in 2013 on four farmer fields in Yilou, a village located in semi-arid Central Burkina Faso. We evaluated the effect of different amounts of locally available woody amendments from native shrubs on soils and crop yields. Preliminary results show that yields increased (in average) from 460 kg/ha to 1063 kg/ha of sorghum when 2 t of woody branches are applied as mulch. These yields remain low but the experiment is promising to show the benefits of this practice and eventually (re) design agroecological systems in the region.
One of the interesting aspects of this experiment is that the protocol is inspired on local farmer innovations and knowledge of the landscape. Our aim is, together with local farming families, to better understand how the system performs in order to optimize and maximize natural resources use and management in a sustainable way. This protocol is being re-conducted in 2014 and will be on 2015 to support analysis and (re)design of current farming practices in Yilou.
You may find more information on this research by downloading on the link below, the scientific poster presented by WASSA at the 1st International Symposium on Agroecology for Food Security and Nutrition, FAO September 2014:
PhD research project on woody amendments
Download the presentation of Georges Félix PhD proposal. Georges started this year (May 2013) as a PhD researcher at the chairgroup of Farming Systems Ecology (FSE) of Wageningen University.
Identify opportunities, trade-offs, and optimisation pathways to enhance resource-use efficiency of semi-arid agricultural landscapes through the use and improved management of woody amendments from the local flora as a renewable source of organic matter to restore soil productive capacity and ensure food security, based on local farming families’ insights and priorities.
Specific Objectives and Hypotheses
1. Characterise current state of soil degradation and identify productive and socio-economic diversity of land-uses.
- Soils are heterogeneous in terms of their degradation state.
- Optimal strategies to reverse soil degradation may be derived by studying current land-uses and management practices.
2. Characterise the availability of ligneous resources and explain landscape-level allocation rules as related to the use and management of native woody shrubs (NWS) as a soil amendment.
- Organic matter from ligneous shrubs is an entry point for sustainable soil fertility management.
- This woody resource can enhance food security since it will not require capital investments, only extra labour.
3. Quantify the effect of ligneous amendment on environmental, hydrological, biological and chemical properties of degraded soils
- Localised soil enhancement is directly linked to physical, chemical and biological soil characteristics
- Appropriate use of NWS will enhance soil quality.
4. Explore trade-offs at the community level in terms of resources use efficiency (land, labour, NWS, among others) in order to attain community defined objectives (food security, farm income, labour use, among others) and contribute with participatory options to re-design of existing farming systems.
- By integrating plot, farm and landscape-scale models for NWS-management along with community-based surveys related to their distribution and governance, it is possible to more effectively allocate resources and enhance overall community well-being.
- It is therefore hypothesized that options to restore degraded soils are not solely technical but are also constrained by social decision-making processes at the community level.