Rethinking Agriculture in the Greater Mekong Subregion
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Rethinking Agriculture in the Greater Mekong Subregion. How to sustainably meet food needs, enhance ecosystem services and cope with climate change. Robyn Johnston - International Water Management Institute
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Rethinking Agriculture in the Greater Mekong Subregion
- 7. Mega-deltas Coasts Plains and plateaus Uplands – forested vs intensively used
- 9. 25% more people by 2050 >25% more food
- 13. Global trade and investment Rubber imports to China
- 15. Agriculture for Development “ GDP growth in agriculture benefits the poorest half of the population substantially more” World Bank 2008
- 18. Rainfall variable, but no trend Stationarity 95% Stationarity 99% Stationarity 99% Scenario A2 Scenario B2 Stationarity 99% Stationarity 99% Stationarity 99% Stationarity 99% Stationarity 99% Stationarity 95% Percentage deviation of annual rainfall from long-term average
- 26. Water management is more than irrigation
- 28. Current recommended practice Clay + compost Clay
- 34. Proposed Don Sahong dam at Khone Falls Spawning Feeding Fish and dams Eggs, larvae, juveniles, adults Adults 60-90 % of migrating fish must pass upstream to maintain viable populations We were unable to find evidence in the literature to suggest that the necessary rates of upstream passage success to sustain even the small species … have been achieved elsewhere Halls and Kshatriya (2009)
Notes de l'éditeur
- Report commissioned by Sida to look at issues around agriculture and environment in the region, in context of climate change - in particular, looking at security of food production over next 20 – 30 years. A lot of CC literature has focused – quite rightly – on long term; wanted to look at the immediate future, period that is being shaped now – out to 2050.
- 5 big messages from the report. Breathing space in next 20-30 years to reshape agricultural systems to deal with more extreme changes expected after 2050.
- GMS region comprises 5 countries of mainland SE Asia plus Yunnan; 5 major river basins inc Mekong and Irrawaddy. Geographically and culturally diverse, but in agro-ecological terms, zones with common production systems and constraints, following similar development trajectories – eg mega-deltas, plains.
- Agro-ecological zones with common production systems, biophysical constraints and risks Similar development trajectories Transferable technologies and lessons
- Agriculture in the region is changing very fast. Lots of influences, but 4 big drivers: population growth, urbanisation, global trade and ec development. Population growth – not as fast as in past, but 25% more people by 2050. That means at least 25% more agricultural production is needed. Global assessments suggest more like 50% because of dietary changes
- Urbanisation –20-30% of people in the region now live in cities. This has a huge impact on the way food is produced and consumed. 50 years ago most of population grew most of own food; means that agriculture has to move to different modes and different products. Also means that many people in rural areas depend on income from work in city, or remittances from family who have move - money flowing back from cities; over a million Burmese work in Thailand, remitting an average of US$300 per person annually to their home villages.
- Trade and investment. Devt of rice exports transformed rice production in Mekong and Chao Phraya during 80’s and 90’s. Transformation of similar magnitude going on now with China opening up to imports. Example is rubber – buying from VN and TH; but investing in plantations in Lao, MY and CAM. N. Laos is transforming at very rapid rate. Some very significant shifts – small scale to plantation; smallholder to commercial; food to non-food; replace forest cover. Debates about land ownership, biodiversity, food security, national sovereignty. . (Ag can no longer be seen as a local or regional issue – biggest markets for rice exports from VN and TH are in Africa, so production in region is very much a part of global food security).
- How does climate change fit with all this? As part of study, reviewed current studies, plus IWMI scientists analysed historical trends and projections from global models. Lot of rhetoric about dire consequences of CC in the region. T is definitely rising, with consistent trend of 1 degree rise in mean annual T over 30- 40 years – for comparison, 2 degree difference in MAT between Chiang Mai and Khon Kaen. Change singificant but not catastrophic
- Rainfall much less clear cut. Rainfall in region is very variable from year to year – flood in 2008, drought this year. BUT No clear trend either over last 50 years or in projected rainfall patterns to 2050. Hier T, more demand for water, but otherwise very uncertain. Sensible approach is to plan for uncertainty – recognise that variability might increase, make water management a priority. No regrets approach
- Sea levels are also rising – this is a serious issue in area where major productive areas of mega-deltas lie at less than 5m above SL. Risen about 20cm since 60s, expect another 30 cm to 2050, beyond that more rapid 1 m SL rise in VN could affect as much as 5% of land area (mostly in highly productive deltas) and 10% of population. In short term, rise in slow and can be managed; in longer terms, becomes a very significant threat to production.
- Context of rapid change, where climate change is one of a number of drivers. Agriculture in region is already transforming – production has doubled over last 20 years in many sectors, using techniques of green revolution – intensification, irrigation, improved seed varieties, fertilizers, pesticides. BUT has been a significant environmental cost: deforestation, erosion, declines in soil fertility and WQ. What are the elements of a second green revolution that can sustain increasing production without depleting environment? Intensification, diversification, integration across sectors and across landscapes.
- At least 25% more food is needed, but clearly don’t have 25% more land for agriculture – so intensification will have to be at least part of the solution; in a lot of the region, that translates to a second dry season irrigated crop. So Governments and investors very focussed on providing large scale irrigation BUT Rainfed ag still provides 75% of production in region; these are areas with greatest yield gaps and best prospects for significant increases in production. Irrigation very successful in some areas, not technically or economically feasible everywhere; and in some areas has been spectacularly unsuccessful. Eg in Cambodia, a recent study found that only 6% of irrigation schemes working properly, 62% not working at all. Despite this, over a billion in irrigation investment proposed. One way to increase production in rainfed areas is to make better use of the full range of water storage options…
- Important to take a broader view of water in ag – irrigation is not the only way to get water to crops - whole range of proven technologies that have an important role to play in increasing production in rainfed area..
- For example – this field trial that IWMI was involved in in NE Thailand; used clay additives to improve retention of both water and nutrients, very significant increases in yield.
- Second element is diversification. Green revolution was about increasing efficiency of monocultures, but in context of change and uncertainty, diversification of production is very important for lots of reasons. All eggs in one basket argument, both for food and livelihoods. Diverse systems more resilient to climate change. Tradiationally in the region, rice provided bulk and calories; most of the high nutritional value foods came from wild capture and collection – fish for protein, vegetables and fruit from wetlands and forests. Rising population, land tenure issues, deforestation, clearing of wetlands mean that access to wild resources / common pool resources is decreasing. Have to build nutritional balance into ag systems.
- Fish. Provides 40-80% of protein; even in mtns >50% are fishers. Importance of the natural capture fishery to region can’t be overstated. It is an integral part of food production systems. It is a free resource. It is available to the poorest. Under pressure from overfishing, but just as much (or more) from loss of habitat – clearing of wetlands, disruption of floodplains, and blockage of migration paths. It is CRITICAL that fishery be managed as part of the food production systems. Food security of region rests on fishery. Aquaculture an important developing sector, but still only 10% of production and relies on capture fishery for stock and feed. Bnd b/w aqc and capture hazy anyway – studies in Cambodia indicate that even in Battambang value of fish caught from paddy field more or less equals value of rice. Important to take that into account when thinking about intensification.
- Fish are a free resource – but still have to be managed. If you don’t protect their habitat, you lose the fish. Mekong system has one of the largest inland fisheries in the world, based largely on migratory fish species that spawn in the river and tribs, but feed in Tonle Sap – big, diverse, interconnected system. Currently proposal to build dams on mainstream Mekong - even small ones such as Don Sahong will block fish passage. WorldFish study from last year found that there were 58 migratory species, almost 40% of the total catch weight, >US $1,000 million per annum ; to maintain populations need 60 – 100 percent passing upstream. Very important study – indicates that very little likelihood that impacts of dams can be mitigated - that is, mainstream dams will inevitably lead to a significant decline in the migratory fishery of the Mekong. Need to give very serious consideration to whether that is a price we are prepared to pay.
- So this brings us to another of the big messages from this report. Agricultural landscapes provide lots of benefits other than crop production. Term “ecosystem services” is coming into common use, and it is an important concept. Some of these are about protecting or enhancing production – like protecting fish habitat – but some are about other things.
- Eg landscapes provide and regulate water supply. If you do this (PHOTO) you get this (PHOTO). Cyclone Nargis illustrated that if you clear mangroves, much more vulnerable to storm damage – as well as losing fisheries habitat. If you put roads and levees through floodplains, you get floods in places you used not to. Need to recognise and value these functions of the landscapes, and move to a model where we manage agricultural landscapes to retain them – because NOT to do also threatens the productive capacity.
- SO – important message is that ag landscapes have to be managed for multiple purposes, not just for crops and livestock. Two aspects to this. First, integrating and optimising production across sectors – rice / fish is one example; small scale aquacutlure; integrating livestock into grain production systems; livestock grazing in upland forests. Traditional small holder agriculture has actually been very good at this – aim is to retain that while scaling up production. Intensification often focuses on optimising single crop – have to look more broadly than that.
- Second is need to integrate and optimise across landscapes, to ensure best use of land and best mix of land uses, taking into account functions other than straight agriculture. You can only push the crop productivity of a field so far – but if look at a whole landscape, and move production to the most suitable areas, you have much better chance of both improving production and protecting the resource base. First green revolution was about mazimising field productivity and individual farmers; second will need to be about working with communities to optimise productivity across a broader landscape.
- All sounds very sensible and straightforward – and there are very good examples within the region, for example, community forestry initiatives in Cambodia to conserve forests while managing access to grazing on a community basis; and community fisheries groups which work to protect habitat as well as control access and catch. But in many cases, you are seeking change from poor farmers who have very few options. Change is not going to happen of its own accord. Government, companies and communities have to work together. It will take changes in the way we view and value ecosystem services, and in the way common property resources are managed and owned; changes in land tenure arrangements; and changes in markets. For example Growing understanding of importance of forests in sequestering carbon, and schemes are being established to pay communities to retain their forests – agricultural landscapes can also play an important part in that, as well as regulating water and nutrients. Payment for environmental services, and other financial mechanisms are ways to kickstart change.
- 5 big messages from the report. Breathing space in next 20-30 years to reshape ag systems to deal with more extreme changes expected after 2050