Initial spacing of teak (Tectona grandis) in northern Lao PDR: Impacts on the growth of teak and companion crops

Teak (Tectona grandis) has been planted extensively by smallholder farmers in Luang Prabang province of northern Laos, primarily in small woodlots established at high initial stocking rates with little/no management until the largest trees are harvested selectively, commencing at 15–20 years after planting. This study used a Nelder wheel experiment planted in 2008, and measured annually after the end of the first 10 growing seasons, to evaluate the effects of the initial planting density on the growth of teak. The potential for intercropping established teak was also evaluated using this Nelder wheel, when the trees were 5–6 years of age, to emulate what might be achievable from companion cropping under an agroforestry system with teak. Individual tree diameter was maximised at the lowest initial stocking, but tree height showed optimum development between 637 and 1020 trees ha−1. While standing volume (m3 ha−1) was maximised at the highest initial stocking (2424 trees ha−1), merchantable volume maximised at initial stocking rates between 423 and 637 trees ha−1. Companion cropping demonstrated that modest yields of maize, cassava and pigeon pea are possible under established teak, where the spacing between trees exceeds 8 m. Both maize and cassava achieved yields of over 2 t ha−1 with a spacing of 8 m between trees, while pigeon pea achieved 3 t ha−1 at 10 m spacing between trees. These results demonstrate that the adoption of reduced initial stocking rates for teak (i.e. below 1000 trees ha−1) can significantly increase the growth rates of teak, improving individual tree volumes, and potentially reducing time to commercial harvest. Further, where row spacing is at least 8–10 m, these results suggest that extended periods of companion cropping (2–6 years after planting) may be possible. Finally, given that Lao farmers are reluctant to adopt pre-commercial thinning, serious consideration should be given to the promotion of simple, regimes for teak woodlots using an initial stocking rate of around 600 trees ha−1. Alleys widths of 10 m are recommended for farmers wishing to establish grow teak in an agroforestry system and extend the period for companion cropping. Nevertheless, revision of Government of Lao policy frameworks are required to support the adoption of more appropriate initial spacing in teak woodlots and agroforestry systems by smallholders

Imperata Grassland Mapping in Northern Uplands of Lao PDR: Area, Distribution, Characteristics, and Implications for Slash-and-Burn Cultivation

Slash-and-burn cultivation (SBC) is an important food and cash crop production system in mountainous regions of many countries in Southeast Asia. While links between unsustainable SBC and the formation of Imperata grassland (IGL) have been well documented, there has been limited research on the issues with the intention of providing appropriate information to communities in Laos aiming at better use of natural resources. This paper reveals the IGL area, distribution, and characteristics in the uplands of northern Laos, and discusses the importance of IGL for upland development based on the synthesis of remotely sensed Landsat-5 TM and GIS data. We have demonstrated the potential use of geoinformation technology as a set of informatics tools that can be applied in other area studies in Laos. Nineteen land uses/land covers of 196,317 hectares in Nambak District in northern Laos were mapped with an overall accuracy of 92.1% and a kappa statistic of 91.3%. IGL achieved >90% mapping accuracy. The current IGL was estimated at about 2.5% (4,878 hectares) of the district area and characterized as a "micro-grassland," with most patch sizes being less than half a hectare. About 37% of the district area in the southeastern part was identified as the most Imperata-infested zone. The study suggests that improper SBC intensification into more permanent crop production systems is a major cause of Imperata infestation in the upland areas and that the spread of IGL can be a threat to the productivity and sustainability of traditional SBC systems and already intensified land use systems. In order to utilize land resources more effectively, government intervention is indispensable; and development efforts should initially focus on the most affected areas

<Research Report>Farmers' Perceptions of Imperata cylindrica Infestation in a Slash-and-Burn Cultivation Area of Northern Lao PDR

This paper discusses farmers' perceptions of Imperata infestation and its impact on agricultural land uses in a slash-and-burn area of Nambak District in Luang Prabang Province, northern Laos. Our study showed that slash-and-burn cultivation (SBC), which has been practiced for generations, remains the main agricultural land use system and provides an important source of food and income for farmers. Imperata, which first took root one and a half decades ago, is gradually proliferating, affecting the livelihoods of nearly 38% of households in the five target villages of this study. The positive cause-and-effect relationship among such factors as accelerated land clearing, young fallows, declining soil fertility, and land shortages—suggested to be the main cause of the Imperata infestation—has reduced not only cultivable land but also its productivity. According to the majority of farmers, the most significant problems caused by Imperata infestation are reduced crop yields, increased weeding, and reduced crop growth. To overcome the problems, farmers employ a combination of strategies—the most common being weeding, fallowing the land, applying chemicals, and exchanging labor. However, the implementation of these strategies is encumbered by many constraints, primarily lack of labor and capital, rice insufficiency, and limited land. Given the constraints and the available technologies, it will be very difficult for farmers in the study area to adopt a more permanent, diversified, and productive agricultural system, which is a high priority of government development policy in the uplands. To meet this challenge, the thrust of research and development communities working in the uplands should be on more systematic and integrated interventions that combine technological, social, economic, and political resolutions based on knowledge of the causes of Imperata infestation, the problems it creates, management strategies to cope with the infestation, and the specific constraints perceived by farmers

Sustaining Biomaterials in Bioeconomy: Roles of Education and Learning in Mekong River Basin

The demands to improve the livelihood of small farmers require a systemic shift from fossil fuel-based and destructive approaches to sustainable renewable raw materials and non-destructive approaches. This should be accompanied by a fundamental reorganization of education and learning policies to create new bio-oriented value chains for biomaterials, food, wood, and energy, as well as in large parts of the health, manufacturing, and service industries. In the long run, the successful implementation of bio-oriented production depends on the systemic linking of both first- and second-hand learning in communities in rural as well as urban settings. The purpose of this paper is to present a concept for the co-design of a new curriculum to better equip new graduates with the ability to support the effort of the sustainable production of biomaterials that are non-destructive to the environment. To sustain biomaterials and enhance non-destructive ways of thinking, learning needs a community of practice in both online and onsite platforms—allowing students to better understand and support cascade use. Therefore, the use of by-products and recycling products after use will increase in importance. A community of practice, and institutions, must create education and learning platforms for improved actions regarding biomaterials across generations and experiences, which will subsequently be integrated into the circular value chains of the bioeconomy. The first- and second-hand learning to sustain these value chains depends on higher education and learning institutions with both legal mandates and systems approaches

Sustaining Biomaterials in Bioeconomy: Roles of Education and Learning in Mekong River Basin

The demands to improve the livelihood of small farmers require a systemic shift from fossil fuel-based and destructive approaches to sustainable renewable raw materials and non-destructive approaches. This should be accompanied by a fundamental reorganization of education and learning policies to create new bio-oriented value chains for biomaterials, food, wood, and energy, as well as in large parts of the health, manufacturing, and service industries. In the long run, the successful implementation of bio-oriented production depends on the systemic linking of both first- and second-hand learning in communities in rural as well as urban settings. The purpose of this paper is to present a concept for the co-design of a new curriculum to better equip new graduates with the ability to support the effort of the sustainable production of biomaterials that are non-destructive to the environment. To sustain biomaterials and enhance non-destructive ways of thinking, learning needs a community of practice in both online and onsite platforms&mdash;allowing students to better understand and support cascade use. Therefore, the use of by-products and recycling products after use will increase in importance. A community of practice, and institutions, must create education and learning platforms for improved actions regarding biomaterials across generations and experiences, which will subsequently be integrated into the circular value chains of the bioeconomy. The first- and second-hand learning to sustain these value chains depends on higher education and learning institutions with both legal mandates and systems approaches