Revista de Investigación Agraria y Ambiental

13-25

Authors: Sonia Esperanza Aguirre Forero, Nelson Virgilio Piraneque Gambasica y Juan Carlos Menjivar Flores

Black Sigatoka (Mycosphaerella fijiensis Morelet) disease is the greatest limiting factor affecting banana crop production across the world. The pathogen´s severity has reached epidemic levels and is exacerbated by the cultivation of monocultures and genetically uniform clones. In Colombia,losses occur in the exporting regions of Uraba and Magdalena, where its management depends on the use of agrochemicals, without achieving eradication. In the search for methods to reduce the pathogen’s effect within the banana zone of the departamento del Magdalena, Colombia, the relationship between climate, soil properties, and the presence of the disease was determined. Were utilized data from geographic informational systems, digitalized the data from the soil variables reported in the soil study conducted by IGAC (2009), records from weather stations in the region, and data showing the incidence rate of the pathogen. As a result of the study were established three areas (high, medium and low incidence rate) and discovered a positive correlation between the incidence rate of the disease with precipitation (r = 0.56), interchangeable magnesium, Mg+2 (r = 0.45), microporosity (r = 0.40), clay content (r = 0.54), and evaporation (r = 0.51). Were observed that there are soil conditions that influence the presence of the disease, variables that should be kept in mind in the management of banana cultivation.

37-48

Authors: María Alejandra Trujillo Toro y Juan Fernando Ramírez Quirama

This study analyzes bioremediation processes of hydrocarbon contaminated soils in Colombia as a sustainable alternative to the deterioration of environmental quality by hydrocarbon spillage. According to national and international environmental law, all waste contaminated with hydrocarbons is considered dangerous waste, and therefore it cannot be released in the ground, water or be incinerated. Such legislation has motivated companies around the world to implement treatment processes for contaminated soils. Within Colombia, oil companies have been implementing the bioremediation of hydrocarbon contaminated soils in order to manage the waste coming from activities of oil drilling, refinement, transport and distribution.These practices must be considered viable for their ease of implementation, their low overhead costs, and for the benefits they provide towards environmental quality. Among the positive impacts that these practices have generated, it may consider the following: a solution for the problem of hydrocarbon contaminated soils, alternatives for the ultimate disposal of said waste without affecting ground, water or air resources, the low cost of the operation, and the technical experience of sustainable development which can continue to be implemented in companies dealing with dangerous waste.

63-71

Authors: Alejandra Plata Pinzón, Sandra Milena Ramírez y Campo Elías Riaño

Goat milk whey is a byproduct of low economic value, and is perceived within Colombia as industrial waste with a negative environmental impact on ecosystems (BOD and COD of 60,000 ppm and 80,000 ppm respectively). Therefore this paper seeks to characterize this whey, and evaluate the effectiveness of the Lactobacillus Helveticus (LH) strain from 0 to 0.91 for the production of lactic acid from whey goat milk enriched with three nutrients. The variables studied follow a Greco-Latin model. To this effect, 16 kinetics were conducted in an intermittent bio-fermenter containing 250 milliliters of goat milk whey wherein the highest production of lactic acid, 17.72 grams per liter, is achieved after 50 hours for a medium containing 2.5% yeast, 0.6% riboflavin, 0.45% ammonium sulfate, and the bio-fermenter operating at 42 ° C. The study concludes that apart from producing lactic acid, LH is an alternative towards avoiding contamination of ecosystems in as much as it would generate an added value to the cheese industry.

85-97

Authors: José Alejandro Cleves Leguízamo, Javier Orlando Orduz Rodríguez y Jorge Armando Fonseca Carreño

Agricultural technology has significantly increased production by relying on monocultures. Conventional practices are reaching the limits of unsustainable agriculture, characterized by high pollution rates, natural resource degradation, overuse of agrochemicals, materials and energy; all towards low or no profitability. Therefore the production process has to be reoriented by implementing an agroecological approach more closely linked to the environment and more socially sensitive, and which promotes the design of sustainable agroecosystems with an integrative vision. The aim of this paper is show the results of research conducted between 1994 and 2012, concerning the systematics of citrus production under tropical conditions, specifically in the foothills of Meta Department in Colombia. As a result of this review, missing elements were identified which serve as a basis future research projects towards the establishment and development of sustainable and agroecological units.

109-121

Authors: José Manuel Alba Maldonado, y Andrea Carolina García Cabana

The following article is the product of a master`s thesis in Rural Development, entitled “Post-rural development. A pedagogical proposal for the recovery of memory in the municipality of Toca-Boyacá”. The article is divided into three parts: the first focuses on describing the problem and the objective, and is centered on a critique of development while arguing for post-development as a viable route, based on the collective memory of a pedagogical proposal. The second part is a brief description of the methodology of the study, placing it in a historical hermeneutic focus using an ethnographic method that recovers the collective memory of the municipality, and participatory action research relating to students of the Instituto Técnico Agrícola de Toca. Furthermore, this part includes a literary review on the concept of post-development. The last part presents the results, divided into two sections, the first showing, the fruit of ethnographic investigation, the recovery of memory, discovery of historically and culturally important sites, and folktales among others. The second part presents the work of the students, their transformation into the role of researchers and their encounter with memory, all framed in the post-development process foundation

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.