vol. 1 núm. 2 (2010)

La Universidad Abierta y a Distancia UNAD ha entrado en un proceso de autoevaluación institucional para lograr la excelencia académica en los programas ofrecidos y en la formación integral de los futuros profesionales. Esto implica el fortalecimiento de la investigación como función sustantiva de la universidad. En este sentido presentamos el segundo número de la Revista de Investigación Agraria y Ambiental (RIAA) teniendo como norte el proceso de indexación, con lo cual a partir del próximo número emprendemos un nuevo reto en el proceso de evaluación ante Colciencias para acceder al Sistema Nacional de Revistas Científicas y Tecnológicas Colombianas y pertenecer al Índice Bibliográfico Nacional Publindex. Nos anima saber que podremos contar con la participación activa de todos los miembros de la comunidad científica que participa con RIAA, en el momento de la apertura de la convocatoria, evaluación de los manuscritos y corrección de los mismos; la calidad y profundidad manifiesta la capacidad de investigar, analizar y transmitir las ideas que se desean expresar. Esperamos que la indexación transforme la revista en su versión impresa como en línea y se mantenga el espacio propicio para quienes deseen publicar y difundir en el medio académico los resultados de sus investigaciones y trabajos, así como sus reflexiones y ensayos sobre los temas agrarios y ambientales.

This study focuses on Assessment of Environmental Sustainability in Three systems of agricultural production: Conventional, Agroecological and Transition to Agroecological. The conventional system is a system that uses chemical supplies such as herbicides, insecticides and pesticides, heavy machinery such as tractors and irrigation, and emphasis on agriculture as a business. The Transition to Agroecology systems is in the process of conversion from conventional to agro-ecological technology. In the Agroecological farming systems there is a strong human-nature relationship. Studies of Sustainability of production systems are a valuable tool to determine the impact of agro-ecological technologies and identify weaknesses in systems that threaten their sustainability in the short, medium and long term. They allow fast and continuous monitoring within systems, which facilitates their assessment, monitoring and improvement.For the assessment of environmental sustainability the methodology known as Framework for Assessment of Natural Resources Systems was adopted, incorporating sustainability indicators (MESMIS). The attributes evaluated were productivity, adaptability, resilience, self-management, reliability and stability.The agro-ecological production system is environmentally more sustainable than conventional production and transition to agro-ecological systems, because this production system emphasizes the conservation of natural resources, preservation of biodiversity, the use of biological supplies for control of pests and diseases and there is an interaction between man and nature that is not mediated by agro-productivity but respect for the cycles, rhythms and rhythms of nature, forming a biologically diverse landscape and rich in singularities.

Case studies and modeling of logistics systems are the basis for the formulation of the content and structure of a reference model for the organization and management of Value Networks as a higher stage of integrated development of supply chains. The definition of a mathematical model for the balance of the Value Network can reveal the characteristics and principles of organization and management of Value Networks.The instrument obtained enables supply chains to assess their level of development and identify the characteristics that should be developed to reach the concept of Value Network, which is based on knowledge development and environmental integration as supports of the same and its competitive position in the global market.Proper integration into the model of environmental factors ensures that Value Networks are inserted into the objectives of promoting sustainable development. The current concept of logistics flow is extended to incorporate within it the exchange of energy, resources and impacts to the environment. The research methods used were based on a combination of study and experimentation of cases and the conceptual and mathematical modeling of systems.

The patterns of current land use in the Rabanal paramo suggest a slow and progressive deterioration of the vegetation of this ecosystem, probably due to the current practice of disturbances imposed apparently largely by human causes, mainly the expansion of the agricultural frontier (mechanized potato crops) and grazing. The typical situation of the pattern of occupation and land-holding in these places, as well as the established production system, is the starting point to determine its effect on this sector of the Rabanal paramo ecosystem and define whether or not this fact is crucial to its conservation and management.The study was conducted in three stages that included the characterization of the area done through surveys, a review of primary and secondary education, followed by field work, and final tabulation of information.The present study obtained results which were intended to contribute to the knowledge of current land use in a sector of the settlement of San Antonio - Township Guachetá, bordering the Rabanal Paramo and with this give the necessary foundation for understanding how anthropogenic intervention operates in the area and its implications for vegetation dynamics and knowledge of its production systems.

Rural Schools of Agroecology (ECAS) are a strategy of sustainable endogenous development (DES) “To Live Well” in Andes Tulueños (Valle del Cauca). This paper analyzes the philosophical, methodological and ethical-political approaches that guide the formation of the ECAS in two settlements in the municipality of Tuluá. The methodology is framed in Research-Action-Participation (IAP) and the Historic Logical Cultural Approach (HLC). ECAS as a strategy of DES becomes spaces of resistance for the rescue of culture, history, territory and care of natural assets by the revaluation of local knowledge and the historical contents that have been excluded by the dominant discourse of the West. Rural farmers exist because they have historically managed natural assets in a sustainable manner.

The principal objective of this study was the production of intermediate syrups by enzymatic hydrolysis using the enzyme α-amylase on solutions of 36 and 46% (D. rotundata) The response variable was the dextrose equivalent in each syrup obtained. A completely randomized design was used. The data was analyzed using Statgraphics ® statistical package. The products obtained were intermediate sweeteners syrups with a dextrose equivalent of 18.81 and 22.15%, respectively; after liquefaction, -which allows classification as a low conversion syrup because of its low content of glucose syrups- the syrups obtained can be used for their functional properties as intermediate syrups or as raw material for various food industry processes such as fermentation by yeast or obtaining syrups rich in glucose by saccharification. This allows establishing a guideline for the use of yam as a non-conventional raw material in the production of products from starch.