Direct seeding mulch-based cropping systems for rice-beef production in the plain of Jars. Xieng Khouang province,Lao PDR: an example of "creation-validation" méthodological approach.
The Plain of Jars is an acid, infertile savannah grassland covering an area of about 60,000 ha in the western region of Xieng Khouang Province, northeastern Lao PDR. In this
ecology, farming systems are mainly based on lowland rice cultivation and extensive livestock production. An increase in rice production and intensification of the livestock industry are two key components in the Lao government's poverty alleviation strategy for this area.
This rice-beef system "creation-validation" process shows the need to maintain research activities to feed the development process and the merits of the approach for determining the potential for technology dissemination.
The results of the WSA analysis are promising, highlighting the positive features of forage species like B. ruziziensis and S. guianensis, which seem able to aggregate smaller soil particles. Annual records should be made for B. ruziziensis, S. guianensis and others systems, and linked with analysis of microbial activities to show the beneficial functions of each species or system in soil aggregation. It is difficult to interpret the positive features of species in regard to bulk density and soil permeability as interaction is complex and various parameters are involved. At the same value of bulk density, this parameter will be affected by article size and arrangement, and organic content. In the case of rice and pine forest, the lower bulk density is mainly related to macro-porosity (high level of permeability). In contrast, B. ruziziensis and S. guianensis showed, for lower Da, a lower value of permeability probably related to an increase of micro-porosity. This characteristic has to be analysed during subsequent measurements of Da and soil permeability data as micro-porosity is a main component influencing water retention.
DMC Systems for Rice--Beef Production in the Plain of Jars, Xieng Khouang Province, Lao PDR: Province, An Example of Creation--Validation Methodological Approach