Some remarks and experiences on higher education and sustainable development

7Education for sustainable development should be based on proper environmental management. The general objective of this study is to highlight key aspects of environmental education, with specific objectives. Inclusive education addresses the learning needs with a focus on those who are vulnerable to marginalization and exclusion. Ethics plays a vital role in environmental management and should be a cornerstone to raise awareness of new forms of relationship with the particular and global environment. The cosmovision of indigenous peoples should be respected, including the indissoluble union of each culture with the environment. The feminization of labor is relevant in horticulture crops, with an active role of women in the organization of work. The connections between education and the world of work are key, with preparation for new and indeterminate forms of employment, paying attention to social skills in the context of increasing globalization. University Social Responsibility (USR) implies that the University must act ethically in knowledge transfer, promoting sustainable development. Sustainable development involves new systems of thought, it requires creativity and critical thinking, and an alternative is the creation of role-playing, to lead people to thinking in different ways. It is essential that the new professionals act without static patterns, integrating interdisciplinary teams, to search for the answer to a problem, offering original and innovative alternatives

A soil quality index to evaluate the vermicompost amendments effects on soil properites

502-510The aims of this work were 1) to evaluate the changes in soil properties with the application of different amounts of vermicompost (10 and 20 Mg·ha–1), and 2) to construct a soil quality index that allows the evaluation of changes in the most sensitive soil parameters. The study was carried out in a cattle field of General Alvear, Buenos Aires, Argentina. Vermicompost application showed a positive effect on most of the chemical and biological soil properties evaluated, especially with the higher dose (20 Mg·ha–1). There were slight but significant increases in electrical conductivity and soil pH with the higher dose of vermicompost. Physical soil properties were not affected by the vermicompost amend-ment. The SQI showed a significant increase of soil quality with the vermicompost dose of 20 Mg·ha–1, especially by enhancing the biochemical and biological properties

Stevia, ka'a he'e, wild sweet herb from South America : an overview

746-750The use of Stevia rebaudiana Bertoni, perennial indigenous native plant from the tropical region of South America is presented, with a brief outlook on the history and uses of the wild plant by Guarani Indians, the crop domestication, and the authorization of its use as a natural sweetener in food and beverages. Other aspects considered are natural glycosides and physicochemical properties for food processing, nutritional information, medicinal properties, Stevia market and household uses. The future of this plant is promising but more research is needed to ensure use of leaves and steviosides, and also to study cultivation practices in various regions of the world

Sustainable management in pecan cultivation in Argentina

243-248Pecan nut "Carya illinoinensis" is native from central and western U.S.A. and arrived in Argentina in the nineteenth century. The difference with other nuts is that it presents an 80 percent oil composition, with polyunsaturated fatty acids omega 3 and 6 that help to reduce cholesterol and also prevent the risk of cardiovascular disease. It contains an antioxidant: vitamin E, and has a high content of fibre that helps to prevent colon cancer. Reduces bad cholesterol, helps keep blood pressure low and is recommended especially for patients with cancer and cardiac problems. A pecan sustainable farming system intends to be productive but at the same time, to preserve enviromental quality, favouring the use of biological practices over chemical inputs. Surface application of compost to pecan trees, is a common practice in organic orcharding. The objectives of the work were to compare compost and vermicompost with liquid fertilizer and a control without fertilization in a completely random block design with four replications, in a one-year crop with a planting frame of 8m x 8m. The application of organic amendments produced statistically significant changes in soil properties with reference to inorganic fertilizer, especially in the total carbon, microbial biomass carbon and phosphorus. Compost and vermicompost treatments produced statistically significant increases in factors related to production as tree height and diameter

Distintas fracciones de fósforo en suelos del norte de Entre Ríos

p.59-62El objetivo del presente trabajo fue evaluar y relacionar las distintas fracciones de fósforo en dos series de suelos con características vérticas. Durante las cuatro estaciones del año, se efectuaron las siguientes determinaciones analíticas: P total, P inorgánico total, P orgánico total, P-Bray 1, P-Olsen, Carbono orgánico total y pH en agua, en las series de suelos G arat (A rgiacuol vértico) y Esmeralda (Peluderte argiacuólico) bajo pastizal natura. El contenido de P total fue bajo y el porcentaje de P orgánico fue de un 63 por ciento, presentando su mayor valor durante el invierno. Esta variación estacional no fue significativa en los contenidos de P-Bray y P-Olsen. Esta homogeneidad puede estar relacionada con las características intrínsecas de los suelos vérticos, hecho que les confiere una especial capacidad buffer de fosfatos. Los niveles de P extractable fueron siempre deficientes, extrayendo Olsen un 62 por ciento del total extraído por Bra

Effects of two plant arrangements in corn (Zea mays L.) and soybean (Glycine max L. Merrill) intercropping on soil nitrogen and phosphorus status and growth of component crops at an Argentinean argiudoll

22-31Intercropping systems can provide many benefits through increased efficiency of land and light use. The objectives of this study were to assess the main effects on a soil and plant growth of two arrangements of corn - soybean intercropping. In a 1-year experiment at 2011, the following treatments were randomly assigned in a CRD to 16 plots located on a vertic Argiudoll from Argentina: sole corn (Zea mays L.), sole soybean (Glycine max L.), corn-soybean 1:1 intercropping and Corn-soybean 1:2 intercropping. Nitrate levels were modified by treatments, but these treatments did not affect available P contents due to very high levels of this element during the whole cropping cycles. The practice of intercropping did not enhance water uptake by crops in relation to sole crops, as might be expected from complementary root systems and development timelines. Corn N status improved with intercropping probably due to an enhanced growth of plants and their roots, but soybean chlorophyll content was decreased by intercropping treatments. Yield and growth of corn were stimulated by intercropping systems, but this system depressed soybean growth, particularly at 1:1 corn-soybean ratio. Based on the remarkable dominance of corn crop observed at this arrangement, it can be concluded that a 1:2 corn-soybean ratio could be more beneficial in terms of more symmetric ecological interactions

Glomalins and their relationship with soil carbon

5The activity of bacteria and fungi is a relevant issue in the process of humification of organic matter and physical stability of the soil, standing out the role of arbuscular mycorrhizal fungi (AMF). AMF synthesize a recalcitrant glycoprotein called glomalin, with hydrophobic characteristics. GSRP (glomalin soil-related protein) is the generic product of proteins extracted from soil. The aim was to quantify GSRP and evaluate its share in the total soil organic carbon (TOC). GSRP presented a direct and positive association with soil TOC (R²:0.73). The quantitative participation of GSRP regarding TOC (GSRP / TOC) revealed that as TOC content decreases, GSRP proportion increases. Within the TOC range explored in this paper (1.3 to 3.2%), the glomalin related protein pool of soil changes about 9%, representing between 27% and 36% of TOC. This behavior would indicate an increase of resistant carbon forms counteracting the effects of carbon loss

Catabolic response profiles, catabolic uniformity and richness as microbiological indicators in a soil of Pergamino, Buenos Aires Province, with and without previous application of glyphosate

85-91Incubation assay in trays was performed with two soils with different application histories of glyphosate: no application, and previous application. The soils used were Typic Argiudolls of Pergamino, province of Buenos Aires, and the treatments were: control (no application), and 20, 200 and 2000 mg of active ingredient per kg of soil. Sampling was performed at the beginning (T0) and 45 days after (T45). Catabolic response profiles (CRP), catabolic richness and catabolic uniformity were determined according to the methodology based on measuring the differences in respiration induced by substrate in a short time (4 hours). The substrates used in this study were 20, namely, two amines, 5 aminoacids, two carbohydrates, and 11 carboxylic acids. The objective of this work was to compare soils with different histories of application of glyphosate, measuring its effect on catabolic response profiles, catabolic uniformity and catabolic richness. In this study, no differences were observed between catabolic richness among the different sampling times and doses of glyphosate applied. Glyphosate application affected the structure of the soil microbial communities. At the end of the test, soils with all doses of previous herbicide application showed greater catabolic uniformity than soils without previous application

La percepción de la calidad del suelo por parte de los productores en una prueba piloto en el área pampeana

p.97-106Para conocer la percepción de la calidad de suelos por parte de productores agropecuarios del área pampeana se aplicó un cuestionario desarrollado en la Universidad de Nebraska (USA). El cuestionario utiliza propiedades consideradas indicadores de calidad y la calificación es de tipo cuali - cuantitativo, respondiendo a pautas establecidas. La muestra fue de tipo casual y se aplicó a productores de pampa ondulada (PO) pampa arenosa (PA) y pampa arenosa semiárida (PAs). Los resultados indican que para ser utilizado en estas zonas se deben introducir algunos ajustes. Las propiedades hídricas, retención de agua, drenaje e infiltración resultan de difícil interpretación y dan origen a respuestas contrapuestas. Los indicadores textura, actividad biológica, dureza y sensación al tacto requieren de una discusión previa con el encuestado y resultaron de difícil evaluación. La calificación final correspondió a 79 por ciento de la calidad en PO, 62 por ciento en PA y 56 por ciento en PAs. La identificación de rasgos positivos y negativos en las percepciones de los productores respecto de la calidad del suelo laboreado permitió recopilar información para el diseño de políticas de gestión. Se considera que la aplicación del cuestionario tiene un doble valor, el de enseñanza, por la inquietud que despertó en los productores y el de reconocimiento del recursos suelo. Se introduce modificaciones a ser aplicadas en futurras evaluaciones como la variabilidad espacial que responde a la morfología del paisaje y que es incluida an la valoración de los encuestados

Pedogénesis de sedimentos contaminados y dragados del Río Reconquista : evaluación y diagnóstico

323-339Se efectuó una evaluación de sitio sobre un relleno de sedimentos dragados al río Reconquista y dispuestos sobre geomembrana, con sauces criollos como vegetación.. Se tomaron muestras de sedimentos hasta una profundidad de 1 m. Se midieron variables físicas, químicas, biológicas y presencia de contaminantes potenciales. En superficie hubo acumulación de carbono orgánico y cambio de color.. La densidad aparente fue menor a 1 g cm-3 y la porosidad fue por grietas.. El pH medido fue ácido: 3,8 in situ y 4,5 en los ensayos, explicando la presencia de Al, Cd, Ni y Zn en la solución del suelo [relación 1:2,5] luego de 7 años de la disposición.. En superficie, la cantidad total de Cd fue de 1,2 mg kg-1; Cr 16,6 mg kg-1; Cu 43,9 mg kg-1; Ni 14 mg kg-1; Pb 32,9 mg kg-1 y Zn 131,7. mg kg-1. Mediante espectrometría de masa se identificaron compuestos orgánicos volátiles [PHAs] confirmando la contaminación original de los sedimentos.. La distribución de carbono orgánico en el perfil permitió inferir un proceso de atenuación natural.. Se aplicó el test TCLP [de calidad de lixiviados] para evaluar técnicas de estabilización de metales, con cinco tratamientos: testigo, cal en dos dosis de enmienda - sedimento 1:20 y 1:50, cemento en idénticas dosis y fertilizante superfosfato triple en dosis 1:40.. El TCLP produjo estabilización al 100 por ciento de Al, Cd y Ni pero no de Zn para las enmiendas con cal y cemento en ambas dosis.. El tratamiento con fertilizante disminuyó el pH de equilibrio favoreciendo la solubilidad del Al en todo el perfil, del Cd y Ni a profundidad intermedia, sin modificar. la solubilidad del Zn. Las técnicas de estabilización con enmiendas cálcicas serían la mejor alternativa para disminuir el riesgo de biomagnificación por entrada de los metales solúbles en la cadena trófica y podrían generar mejores condiciones para la atenuación de los hidrocarburos