Revista de Investigación Agraria y Ambiental

15-23

Authors: Thomas May, Sesar Rodríguez

Se estudiaron la flora melífera y su floración en la zona del bosque seco subtropical de la Línea Noroeste, de República Dominicana. Se aplicó una encuesta a 30 apicultores locales, así como 4 entrevistas semiestructuradas, sobre plantas de importancia para la actividad apícola. Se calificaron las plantas según su importancia; mediante observación, se confirmaron en campo las visitas de las abejas a las especies observadas y se consultó información secundaria sobre fechas de floración y características melíferas, información secundaria, y se aplicó el índice de Jaccard para determinar el grado de similitud entre el conjunto de las plantas mencionadas por los apicultores y las observadas en el campo. La coincidencia, relativamente buena, entre las plantas identificadas por los apicultores y las plantas en las que se observaron visitas de abejas en el campo confirma la validez del método. La mayoría de las plantas identificadas como melíferas son silvestres y pertenecen a la vegetación del bosque seco. Hay un período de floración abundante de marzo a junio y un período de escasez de septiembre a diciembre. Se recomienda la conservación de áreas significativas de bosque seco y de manglares en las áreas costeras, así como el establecimiento de cercas vivas y otros sistemas agroforestales en el paisaje agrícola, que tengan en cuenta especies arbóreasrelevantes para la apicultura, con floración complementaria.

41-46

Authors: Óscar Eduardo Sanclemente Reyes, Carlos Omar Patiño Torres y Liliana Rocío Beltrán Acevedo

In a Typic Haplustalfs (USDA) soil of the municipality of Palmira – Valle (Colombia) the rotation system velvet bean Mucuna pruriens Var. Utilis – maize Zea mays L. was established in design of complete blocks at random with seven treatments and three repetitions. The treatments in the rotation were: T1 (Without M. pruriens and fertilizing), T2 (green manure of M. pruriens without fertilizing), T3 (mulching of M. pruriens without fertilizing) T4 (green manure of M. pruriens more compostado organic manure), T5 (green manure of M. pruriens more fertilizer of chemical synthesis), T6 (green manure of M. pruriens plus complemented compostado organic manure with fertilizer of chemical synthesis), T7 (mulching of M. pruriens plus complemented compostado organic manure with fertilizer of chemical synthesis). The energy balance was characterized and contributes nutritional using software Energy 3.01., from the entrances energetics in each treatment. The greater efficiency was obtained energetics in the T2 with 114.1 Mj.Mj-1 that was significantly greater (p<0.05) to the other treatments. The T5 where fertilization of chemical synthesis was used obtained value of 19.1 Mj.Mj-1, reflecting high entrances energetics and low productivity. The majors contribute nutritional were obtained in T3, T4, T6 and T7. Nevertheless, the treatments T3 and T4 stand out respectively where it was used mulching and green manure of M. pruriens more compost; since they are treatments where more efficient use becomes of the power resources by the use of consumptions readily accessible for the producer, being able to generate benefits like feeding for almost 50 persons.ha-1.year-1. These results suggest this valuable alternative association as for use in familiar agriculture farmer.

53-62

Authors: Luz Elena Santacoloma Varón y Jairo Enrique Granados

Samples were collected from 2 forage plants (leaf stalk) of the species Gliricidia sepium and Tithonia diversifolia in different soil conditions (departments of Valle del Cauca and Cesar) and evaluated for total polyphenol content, total tannins, condensed tannins and Saponinas. The purpose was to detect the effect of the conditions of electrical conductivity on the concentration of these secondary fitobiomoléculas metabolized by the plant cell. We applied analytical techniques and instrumental AOAC (2005) to determine the presence of such fitometabolitos side. The results obtained for each variable were subjected to analysis of variance two-way, in order to determine statistical differences between areas sampled and evaluated species. Additionally, we performed a multiple correlation analysis using the Pearson coefficient, in order to detect any correlation between electrical conductivity and the content of secondary metabolites quantified in the species sampled. It was concluded that the content of total polyphenols, total tannins, condensed tannins and saponins did not show statistically significant differences between the three areas sampled, and there was high correlation between the value of the electrical conductivity of soil and content of secondary metabolites

67-76

Authors: Julián Leal Villamil y Luis Alfredo Lozano Botache

Based on the methodology of potential soil fragility, described by Alarcón and Gayoso (1999), the evaluation and spatial distribution of the potential fragility for erosion and landslides, was carried out in the soils of the municipality of Ibagué. Edaphic variables were taken from units of soils according to two systems of classification: Comité de Cafeteros de Colombia (1973) and IGAC (2004). Environmental variables of precipitation and altimetry were obtained from the hydrographic basin ordination and management plan of the Coello and Torare rivers (CORTOLIMA, 2006) and the forestry planning project for the Department of Tolima(Universidad del Tolima and CORTOLIMA, 2007). According to the numerical information organized in maps and the mathematical models established for the nomograms of the base methodology, the rates of potential fragility of the two phenomena of soil degradation were determined. The results show that with the soil classification system IGAC, the municipality of Ibagué is more sensitive to phenomena of landslides rather than to erosion, opposed to what is shown in the system of the Comité de Cafeteros de Colombia. Both systems coincide in stating that the zones with higher propensity to these phenomena are located mainly near the Combeima Canyon, in the mountainous area near the municipality of Cajamarca, as well as the hills and mountains that surround the urban area.

85-88

Authors: Óscar Emerson Zúñiga M.

In recent decades, the list of concerns which accompanies human existence has donned a new item: the effects lifestyles are having on the ecosystem due mainly to the fact that the changes introduced are of such magnitude that not only is a kind of tropical frog or a tiger that inhabits floodplain systems at risk. There is a pressure factor submittingmillions of human beings located in the most diverse, but at the same time most fragile, ecosystems to a high degree of vulnerability. This moral concern extends to the fields of politics and epistemology where, from the perspective of ecological economics, the relevance of existing indicators for development drawn from neoclassical economics is being questioned, as an expression of a deeper discussion of the relationship of society-nature.