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Sustainability of Dryland Mixed Farming Systems

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Presentation on theme: "Sustainability of Dryland Mixed Farming Systems"— Presentation transcript:

1 Sustainability of Dryland Mixed Farming Systems
Dr Andrew Dougill, School of Earth and Environment, University of Leeds

2 Sustainability of Dryland Mixed Farming Systems
What do you understand by the term – “Land Degradation”? Write down features typical of a farming region suffering from land degradation

3 Definitions of Degradation
“a reduction in the resource potential by one or a no. of processes operating on the land” UN, 1997 “an effectively permanent decline in the rate at which land yields agricultural products” Abel and Blaikie, 1989  Drought - “a period of 2 or more years with substantially below average rainfall” (Warren and Khoghali, 1992)  Desertification - “land degradation in dryland areas” (UNEP, 1997)

4 Sustainability of Dryland Mixed Farming Systems
What are mixed farming systems? What is Degradation? How has / can it be measured? Break Sustainable Livelihoods literature How can SL frameworks be integrated with soil degradation assessments? Case Study – Nutrient balance studies in Molopo Basin, Southern Africa – Dougill et al., 2002 Concept Mapping

5 Dryland Mixed Farming Systems
Mixed farming simply implies use of both arable and pastoral production within household livelihood strategies Is the main production system followed by hundreds of millions of dryland farmers, notably in sub-Saharan Africa Key text book discussions – Whiteside, 1998; Scoones, 2001; Bassett & Crummey, 2003

6 Problems of Mixed Farming Systems
Found in semi-arid and dry sub-humid ecosystems that are seen as suffering from both hunger & poverty (social) and land degradation (environmental) problems

7 Problems of Mixed Farming Systems
Dryland sub-tropical environments typified by soils of low organic matter (compared to temperate systems) and nutrient status (due to intense weathering & leaching) Soils viewed as highly susceptible to wind and water erosion leading to many external agricultural development initiatives (Transfer of Technology) to reduce soil erosion However, now widely questioned, as: “From the early colonial era to the present, attempts have been made to introduce SWC measures in a wide range of settings, yet many have failed.” Scoones et al., 1996; p.1 Partly due to mis-representation of problems

8 Contemporary Debate “Environmentalism in general, & ideas about land degradation in particular .. have been jeopardized by weak arguments about the basis of their environmental appraisal, and can only survive in the new more competetive green political environment if they are more rigorous” “The only valid assessment is by those who may suffer the consequences” Warren (2002; p.457) Oct 8th 2004 – Wangari Maathai wins Nobel Peace Prize for work as leader of Green Belt Movement in Kenya

9 Advantages of Mixed Farming Strategies
Developed from traditional practices using ‘Indigenous Technical Knowledge’ Offers flexibility to enable opportunities to be realised within dynamic environment – e.g. opportunistic cropping when wet; sale of cattle when dry Labour intensive, but low external inputs required so not capital intensive Vulnerability to market collapse, disease & external policy shocks reduced by diversity in production outputs Social networks across regions (& to cities) vital in reducing livelihood vulnerability

10 Land Degradation Research on Mixed Farming Systems
Need to better understand the environmental context of dryland soils, for SWC measures that will increase yields and/or livestock output Must identify the social networks and indigenous knowledge on farming systems that any development initiative must work with Need to discount many conventional wisdoms, e.g. “All soil erosion is bad”; “Gullies are the worst” etc. etc. “Population growth leads to environmental degradation” “Secure (privatised) land tenure is essential for environmental conservation” “Overgrazing is leading to extensive desertification of communal rangelands” Needs case study research involving intensive field study & innovative hybrid research methodologies that seek to establish and measure real environmental changes & their social, economic or political root causes

11 Methods for Assessing Land Degradation
Expert opinion - e.g. Global Assessment of Soil Degradation (GLASOD) - Use ‘Indicators’ Remote sensing - satellite monitoring e.g for green biomass cover Field monitoring - ecological or soil-based Productivity changes - crop yields, biomass production or livestock outputs (FAO statistics) Sample studies at farmer level - Participatory approaches Modelling - e.g. soil erosion hazard maps, GIS etc.

12 Conflicting Land Degradation Messages - through time
UN estimates of Dryland Degradation (Desertification) - 1977 UNCOD - 3,970 million ha 1984 GAP: Mabbutt - 2,001 mill ha Dregne - 3,271 million ha UN - 3,475 million ha 1992 UNEP - 3,592 million ha 1997 UNEP - 1,036 million ha (based on GLASOD, 1990) extended GLASOD using RS database to produce Soil and Terrain Database (SOTER) D.S.G. Thomas (1993) - Sandstorm in a Teacup? GJ 159, 3,

13 Conflicting Land Degradation Messages - Spatially
Global assessments and regional assessments differ to local-scale and some recent national studies e.g. GLASOD v. SA National Botanical Institute

14 Reasons for Conflicting Degradation Assessments
Subjective nature of visible indicators used in expert analysis - e.g. does a gully or a dune really = degradation in economic or social sense? Integration of different information sources - more than just soil erosion Importance attached to environmental sustainability - is some loss of natural resource base acceptable for a socio-economic gain? A. Warren et al., Geographical Journal, 167(4),

15 Problems for Soils and Land Degradation Research
Requires a completely new way of doing research to match holistic view of farming systems and farmers livelihoods “Soil science has been brilliantly informed by reductionist physics and chemistry, poorly informed by ecology and geography, and largely uninformed by the social sciences” Swift (1998) quoted from Scoones et al., 2001 “Land degradation cannot be judged independently of its spatial, temporal, economic, environmental and cultural context. Evaluations are therefore almost infinitely variable and very dynamic” Warren, 2002; p.49. Key aspect is that – Environmental Change  Degradation Global / regional / national estimates contain major uncertainties / oversimplifications

16 Sustainability of Dryland Mixed Farming Systems
What are mixed farming systems? What is Degradation? How has / can it be measured? Break Sustainable Livelihoods literature How can SL frameworks be integrated with soil degradation assessments? Case Study – Nutrient balance studies in Molopo Basin, Southern Africa – Dougill et al., 2002 Concept Mapping

17 Alternative Sustainability Assessments – Sustainable Livelihoods Approach
SL – a way of thinking about objectives, scope and priorities for development, formalised by many development agencies (DFID, UNDP, World Bank etc.) Formalises need for integrated social, economic, political & environmental basis for research “A livelihood comprises the capabilities, assets (both material and social) and activities required for a means of living. A livelihood is sustainable when it can cope with and recover from stresses and shocks and maintain or enhance its capabilities and assets both now and in the future, while not undermining the natural resource base” Chambers and Conway, 1992 See

18 Sustainable Livelihoods Research Framework (DFID, 1999)

19 Soils & SL Research in Practice
See Sahelian Soils debates of Warren et al., 2001 – The Geographical Journal, 167(4), Examines whether ‘capitals’ framework helps assessments of sustainability ‘strength’ “Strong sustainability” - no loss of natural capital (e.g. soil) “Sensible sustainability” - conversion of some natural into other forms of capital, increase total capital base over time “Weak sustainability” - just increase total capital

20 Sahelian Soil Erosion - E. Niger
“Despite high rates of erosion, we find it difficult to decide whether the system is sustainable (using the capitals or any other framework). It is even dubious whether sustainability is an urgent concern” Warren et al., 2001; p.324 Other (more important?) concerns - Rainfall (climate change) pests lack of labour / illness prices Livestock / urbanisation futures => why conserve soils ??

21 Problems of Environmental Sustainability
Drive for soil conservation from agronomists and soil scientists, rather than from local communities Can the sustainability of natural capital conflict with the sustainability of livelihoods (social sustainability) “to be ‘socially sustainable’, some farmers must engage in practices that lead to erosion” (Warren et al., 2001; p.333) How can you monitor / assess the ‘critical natural capacity’ needed for ‘sensible sustainability’ ? Often relates to maintaining environmental diversity that enables risk management by societies Often less visible environmental changes (nutrient depletion) more important than visible soil erosion Concept has serious operational and methodological difficulties

22 Sustainability Science and New Methods of Soil Degradation Assessment
Must involve farmers in assessment process to focus on issues of real concern and with a definite impact on yields Usually involves simple, reliable ‘degradation indicators’ that are well known to farmers – e.g. yellow leaves for N deficiency; stunted patchy crop growth – general nutrient deficiency; scorching of leaf margins, restricted root growth and plant death – low pH leading to metal toxicity See Stocking and Murnaghan (2001) for excellent review

23 Farmer-led Degradation Monitoring
UN FAO now formalising farmer-led assessment approaches to attempt more applicable (than GLASOD) degradation assessments (LADA programme) Starts from Livelihoods analysis of farmers concerns (threats) and opportunities (strengths) with eventual aim to provide improved development support Uses Participatory Rural Appraisal approaches (PRA) such as field sketches, timelines, semi-structure interviews and field nutrient budgets Develop check-list for Participatory Monitoring and Evaluation (PME)

24 Andrew Dougill, Chasca Twyman and David Thomas
Land Degradation in Mixed Farming Systems on the Southern margins of the Kalahari: Soil chemical processes and farmer perceptions Andrew Dougill, Chasca Twyman and David Thomas

25 Methodological Context: Key Research Questions
How best to provide simple, reliable and applicable assessments of land degradation in mixed farming systems? How to integrate simple environmental indicators (e.g. crop yields and growth characteristics, erosion and deposition features) into Participatory Learning and Action (PLA) approaches? What extra information can partial nutrient budget approaches provide for assessments of soil chemical processes (and degradation)?

26 Study Site : Molopo Basin, South Africa and Botswana
Mixed farming region classed by international (e.g. GLASOD) and national surveys (e.g. NBI, 2000 below) as affected by severe degradation

27 Study Site : Molopo Basin, South Africa and Botswana
Traditional system involves transfer of organic nutrients (as kraal manure) from rangeland to arable fields, complementing fertiliser additions Communally owned rangeland, but with individual farmer kraals (manure supply) and privately owned (or leased) arable lands - see Whiteside 1998 for Sn African context

28 Study Site : Molopo Basin, South Africa and Botswana
Low and variable crop growth recognised by increasing no. of farmers as livelihood constraint Fencelines and nebkha dunes around arable fields indicate wind erosion occurrence (but limited extent)

29 Research Methods Aim - combine different information sources for simple and applicable land degradation assessment at a field scale 1. Inventory of conventional environmental indicators of soil degradation (fencelines, nebkha dunes, rills) and livelihoods survey identifying farmers concerns 2. Participatory nutrient budget studies - farmer interviews aimed at quantifying nutrient fluxes at field and farm scales 3. Soil chemical analysis (N, P, K, pH and OM) from fields chosen by farmer 4. Soil degradation discussions - two-way discussion of soil degradation constraints on farming practices and crop yields 5. Local and national workshops

30 Model of Nutrient Dynamics

31 Research Results – Mean Field Budgets
Field nutrient budgets conducted for 24 fields of varying land use over 2 growing seasons – 98/99 drought year; 99/00 wet year Mean budgets show N depletion with good crop harvests, but hide many management – degradation messages

32 Research Results - Key Findings
Field-scale nutrient budget analysis highlight that for 1998 / 99 growing season nutrient inputs > outputs when farmers add fertilisers - excess nutrients will increase risk of soil acidification Manure inputs alone lead to soil nutrient depletion (even for low rainfall study year) Perception of need for no fertiliser addition to groundnuts leading to soil nutrient depletion Integrated nutrient management as used by 2 of 15 study farmers capable of avoiding most soil degradation processes

33 Opportunities Provided by Combining Information Sources
Simultaneous collection of several indicators of land degradation (and processes causing it) leads to more applicable assessment of land degradation and relevance to land users - better assessment Shared understanding of land degradation pressures provides the basis for Learning and Action - better management Improved extension advice can involve some farmers in experimentation, monitoring and evaluation of adaptations to farming systems Lack of farmer interest in integrated nutrient management decisions (due to non-farming livelihood options, or due to lack of manure caused by decline in herd size) will lead to difficulties in ensuring long-term environmental sustainability - i.e. social not an environmental problem?

34 Conclusions Soil fertility assessments in combination with farmer interviews suggest acidification (due to fertiliser inputs) or nutrient depletion (due to reduced manure inputs) are the main processes of land degradation Participatory studies highlight key constraints as a decline in flow of nutrients from rangeland to arable and need to facilitate changes in livelihood systems to encourage integrated nutrient management Institutional frameworks need to enable increased availability and use of organic manure inputs as key factor affecting sustainability of arable production on sandy soils

35 Remaining Research Questions
How worthwhile are Participatory Land Degradation Assessment approaches to – Improved degradation mapping? Farmers management practices? Policy Development and Agricultural Support? Are major environmental issues (e.g. biodiversity loss) or resilience mechanisms (e.g. soil crusts) ignored by participatory approaches? Is applicability & reliability compromised? & how can triangulation of data be improved? Can results / methods be used on a national or regional scale in a cost-effective manner?

36 Preliminary Reading List
Bassett, T.J. & Crummey, D. (2003) African Savannas: Global Narratives and local knowledge of environmental change. James Currey. Dougill, A.J., Twyman, C., Thomas, D.S.G. & Sporton, D. (2002) Soil degradation assessment in mixed farming systems of southern Africa: use of nutrient balance studies for participatory degradation monitoring. The Geographical Journal, 168 (3), Dougill, A.J. & Thomas, A.D. (2002) Nebkha dunes in the Molopo Basin, South Africa and Botswana: formation controls and their validity as indicators of soil degradation. Journal of Arid Environments 50, DFID (1999) Sustainable Livelihoods Guidance Sheets – Hilhorst, T. & Muchena, F. (2000) Nutrients on the move: Soil fertility dynamics in African farming systems. IIED. Hoffman, T. & Ashwell, A. (2001) Nature Divided: Land Degradation in South Africa. UCT Press. Reij, C. & Waters-Bayer, A. (2001) Farmer Innovation in Africa. Earthscan. Scoones, I. (2001) Dynamics & Diversity. Soil fertility and farming livelihoods in Africa. Earthscan. Stocking, M. (1996) Soil Erosion: Breaking new ground. In Leach, M. & Mearns, R. The Lie of the Land: Challenging received wisdoms on the African Environment. James Currey. Stocking, M. & Murnaghan, N. (2001) Handbook for the Field Assessment of Land Degradation. Earthscan. Stocking, M. (2003) Tropical Soils and Food Security: the next 50 years. Science 302: Warren, A., Batterbury, S.P.J. & Osbahr, H. (2001) Sustainability and Sahelian Soils: evidence from Niger. The Geographical Journal, 167 (4), Warren, A. (2002) Land Degradation is Contextual. Land Degradation and Development, 13, Whiteside, M. (1998) Living farms: Encouraging sustainable smallholders in Southern Africa. Earthscan.

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