MEKARN 2001-12: achievements
Contents
The MEKARN program (http://www.mekarn.org), a regional network on sustainable agriculture in South East Asia, financed by Sida/SAREC, has provided the means for incubating agricultural technologies through its core activities including research, research training, and exchange and dissemination of information in the countries in the Lower Mekong Basin (Laos, Vietnam, Cambodia and Thailand). The aim has been the improvement of rural livelihoods through more efficient utilization of local resources, with emphasis on the role of livestock in the farming system and recycling of organic waste through biodigesters. All achievements are results of research performed by students from Vietnam, Cambodia or Laos at Master or PhD level.
The MEKARN program (http://www.mekarn.org), a regional network on sustainable agriculture in South East Asia, financed by Sida/SAREC, had as its core activities, research, research training, and exchange and dissemination of information in the countries in the Lower Mekong Basin (Laos, Vietnam, Cambodia and Thailand). The project, managed by Nong Lam University in Vietnam, was initiated in 2001 with the first phase ending in December 2003, and the second phase in December 2007. In 2007, the achievements of the project were evaluated and endorsed by the Sida Evaluation Committee; and a phase from 2008 to 2011 was recommended and subsequently approved by Sida. The activities in this phase were concentrated on institutions in the poorer countries – in Laos and Cambodia - and in An Giang University in Vietnam, which had recently been established.
The thrust of the MEKARN progam has been the improvement of rural livelihoods through more efficient utilization of local resources, with emphasis on the role of livestock in the farming system and recycling of organic waste through biodigesters and gasifiers. The aim has been to improve the overall use of local resources by considering livestock as fundamental components of environmentally friendly integrated farming systems. The goals have not been on maximizing yields of livestock products but rather how livestock can play a role in the more efficient use of local resources with special emphasis on their effects on the environment. All achievements are results of research performed by students from Vietnam, Cambodia or Laos at Master or PhD level.
Five MSc programs were completed in the period 2001-2012 with a total of 65 students. On average 36% of the students were female. To date 17 students from the region have completed the requirements for a PhD and have received their degree from SLU. Eight students will defend their PhD thesis during 2012. Many of the former students have today positions at ministries, as heads of research institutes/departments at universities or work as researchers.
A total of 198 scientific papers have been published in peer-reviewed journals (http://mekarn.org/home/training/courses/research-papers). Regional workshops were held on 13 occasions, and the proceedings published on the Mekarn web site (http://www.mekarn.org).
More than 110, 000 low-cost tubular polyethylene biodigesters have been installed and paid for by farmers. Large scale biodigesters constructed with high density polyethylene (HDPE) have been installed in 2 cassava processing factories, 2 abattoirs and 26 large pig farms.
With support from MEKARN, the Cambodian NGO CelAgrid imported the first gasifier from India in 2004 (http://www.mekarn.org/msc2003-05/theses05/phallacont.htm) for research purposes. Since then, the gasifier technology has spread considerably with close to 50 large and small units in operation, chiefly in rice mills. At present there are at least three local companies producing gasifiers for the demand of the market in Cambodia.
The gasification technology has also been adapted for use in cook stoves (http://www.mekarn.org/workshops/pakse/html/olivier.docx). Gasifier stoves produce a clean gas with no smoke, thus the technology directly benefits women and children as these are the major players in the process of collecting fuel wood and later its use for cooking usually in open fires.
Biochar is an important byproduct of gasification, whether in up-draft cook stoves or in down-draft gasifiers for electricity generation. Research by MEKARN (http://www.mekarn.org/workshops/GHG-CC/content.htm) has shown that biochar can be used for soil amelioration, supplementation of livestock diets and decontamination of waste water streams. It is also considered to be highly probable that the carbon incorporated in soils in the form of biochar will remain there for thousands of years and thus be a means of sequestering carbon from the atmosphere. Thus the gasification technology has important implications for improving the environment, contributing both to mitigation of, and adaptation to, global warming, climate change and depletion of non-renewable resources. Use of improved gasifier stoves for cooking will directly improve the health of women and children by reducing emissions of Black carbon (www.unep.org/dewa/Portals/67/pdf/BlackCarbon_report.pdf).
Feeding nitrate salts to manipulate the rumen fermentation in ruminants is predicated on the role of nitrate as a preferred sink for enteric hydrogen, resulting in the production of ammonia instead of methane. Nitrite toxicity, previously considered to be a risk in feeding nitrate salts to ruminants, was shown not to be an issue when animals were adapted gradually to incorporation of nitrate salts in their diet (http://www.lrrd.org/lrrd21/1/trin21010.htm) . Since this first report in 2009, Mekarn researchers have demonstrated that nitrate salts reduce methane production in both in vitro and in vivo experiments; and that widely available tropical forages such as the leaves from cassava also reduce enteric methane as do foliages from leguminous shrubs such as Mimosa pigra (http://www.mekarn.org/workshops/GHG-CC/content.htm).
A promising avenue of research is the use of biochar as a feed additive to reduce enteric methane. Recent in vitro incubations with rumen fluid in Souphanouvon University, Lao PDR, showed that biochar at 1% of the diet reduced methane production (http://www.lrrd.org/lrrd24/6/sang24103.htm), This is now being validated in a feeding trial with cattle in the same institution. Forages for pigs and ducks
Research with pigs has been directed to finding alternatives to conventional protein supplements such as fish meal and soybean meal. Initial studies were aimed at finding suitable ways to use the leaves of cassava, in view of potential cyanide toxicity problems . Sun drying and ensiling were found to be effective in reducing the potential risk from cyanide toxicity, and that the ensiled or sun-dried cassava foliage could provide most of the supplementary protein in diets based in rice bran .
Several other forage species such as sweet potato vines, mulberry leaves and water spinach were shown to be potential sources of protein in pig diets. However, most success has been achieved with the use of foliage from Taro, a member of the Aracaceae family. In contrast with most other forages, the stems (or petioles) of Taro are equally valuable as the leaves. The stems are rich in sugars which facilitates the ensiling process, when leaves and stems are ensiled together, rendering unnecessary any other additive. The ensiling procedure is now widely used by farmers who find it much more convenient than the traditional system of cooking or boiling. It has been found that the fibre in Taro foliage is more digestible than in other forages, thus the ensiled foliage has been fed even as the sole diet to both pigs and ducks.
Rabbits are herbivores and in the wild state forage is their main diet. Despite this dietary adaptation, the intensification of rabbit production has resulted in increasing dependency on concentrates based on cereal grains and protein meals as the basis of their diet.
A major achievement of Mekarn research with rabbits has been to demonstrate that there are many types of forage that can support growth and feed conversion rates comparable with those achieved by feeding concentrates. It has been shown that water spinach and sweet potato vines are highly digestible and can provide all the nutrients required for growth, reproduction and lactation in rabbits. As these forages are easily grown in the home garden, these developments target women and children as beneficiaries of this technology.
As with rabbits, intensification of aquaculture has seen the replacement of the natural food chain, by supplements derived from protein-rich byproducts from fish and oilseeds. This intensification of the production process gave initial economic benefits, but created new problems resulting from accumulation of uneaten feed and feces in the ponds and tanks which at the end of the production process were discharged into canals and rivers.
Mekarn research has focused on finding ways to strengthen the natural food chain in aquatic systems, with the dual aim of reducing the dependency on imported feeds and eliminating the pollution. Biodigester effluent has proved to be a valuable fertilizer to stimulate growth of Chlorella the natural feed of many fish species. Duckweed (Lemna spp) appears to offer most promise as a feed that can be grown initially in the same pond as the fish, and then in adjacent ponds fertilized with biodigester effluent. It has been shown that the productivity and nutritive value of duckweed are both enhanced by fertilization with this resource.