ABSTRACT In the Cienega de Chapala region of the state of Michoacan, Mexico, forage crops form a major pillar for traditional livestock systems. In this region, high soil salinity due to poor groundwater quality is a common problem. Thus, the objective of this research was to evaluate the potential of the forage species Vicia sativa L. for improved saline soil in a greenhouse and non-leaching conditions over the course of 90 days. In this experiment, three levels of NaCl salinity were tested: 5.3, 7.12 and 10.8 dS∙m–1. Samples of soil were analyzed for electrical conductivity of the saturation paste extract (ECe), soluble and interchangeable cations (Na+, K+, Ca2+ and Mg2+) content. Then, the forage species Vicia sativa L were divided into three categories (leaf, stem, and root) and their shoot biomass production and Na+, K+, Ca2+ and Mg2+ content was determined. Analysis of variance was performed to examine the effects of salinity on each of the evaluated variables; Tukey’s test was used to detect differences between the mean values of the variables per treatment. In a greenhouse experiment, the species V. sativa is confirmed to be tolerant to a moderately saline level. The high concentrations of Na+ found in both the stems and leaves of this plant confirm that it may be used for the improvement of moderately saline soils. The decrease in pH, ECe, SAR and ESP in the pots via non-leaching conditions confirmed their role in the improvement of the chemical characteristics of the soil.

Abstract In the Ciénega de Chapala región, portion of Michoacán most of the forage crops are the main sustenance of the traditional livestock systems. However, water scarcity and increasing salinity are the main limiting environmental factors that directly affect both its establishment and development. In this research, the ability of germination and emergence of seven forage species was evaluated in in vitro conditions, when exposed to different concentrations of NaCl. The evaluation was carried out in a period of 21 days, in which the seeds were placed in an incubator without light at a temperature of 25/17 °C (day/night) respectively. Acid digestion method was used for the removal of Na+, K+, Ca2+ and Mg2+ cations from the germinated seedlings. Salinity treatments were 0.0 mM, 50 mM; 100 mM; 200 mM and 400 mM. In the imbibition stage a differential response was observed between species under conditions of saline stress, mainly at 200 and 400 mM, producing a drastic reduction in the absorption levels with respect to its own controls and later reflected in its germinative capacity. H. vulgare and L. perenne species showed a lower K+/Na+ ratio, confirming to be more tolerant to this level of salt concentration.

Resumen En la región de la Ciénega de Chapala porción Michoacán la mayor parte de los cultivos forrajeros son el sustento de los sistemas ganaderos tradicionales. Sin embargo, la escasez de agua y la creciente salinidad se presentan como los principales factores ambientales limitantes que afectan directamente a su establecimiento y desarrollo. En esta investigación, se evaluó la capacidad de germinación y emergencia de siete especies forrajeras en condiciones in vitro, al ser expuestas a diferentes concentraciones de NaCl, Se llevó a cabo en un período de 21 días, en el cual las semillas fueron colocadas en una incubadora sin luz a una temperatura de 25/17 °C (día/noche). Se utilizó el método de digestión con ácido para la extracción de los cationes Na+, K+, Ca2+ y Mg2+ a partir de las plántulas germinadas. Los tratamientos de salinidad fueron 0.0 mM, 50 mM; 100 mM; 200 mM y 400 mM. En la etapa de imbibición se observó una respuesta diferencial entre especies en condiciones de estrés salino, principalmente a 200 y 400 mM, al producir una reducción drástica en los niveles de absorción respecto a sus propios testigos y posteriormente se vio reflejado en su capacidad germinativa. Las especies H. vulgare y L. perenne mostraron menor relación K+/Na+, ratificando con ello, ser las más tolerantes ante este nivel de concentración salina.

Abstract: The Duero river basin is located northwest of the state of Michoacan, with an area of 2531.3 km2. A diagnosis of the current situation of its operation, quality and quantity of water from its springs was performed. A total of 52 were identified, of which 49 were afored, yielding a cumulative expenditure of 8.526 m3/s. The waters are mainly exploited for agricultural, urban consumption, aquaculture and recreation. The annual volume of water generated by the springs is 268 876 Mm3, which more than meets the needs of the region. The chemical quality of the springs is excellent for the different uses but not the bacteriological quality. In terms of its condition and operation, only 27 % of them has serious problems of efficient management, which threatens its sustainability.

Resumen: La cuenca del río Duero se localiza al noroeste del Estado de Michoacán, cuenta con una superficie de 2531.3 km2. Se realizó un diagnóstico de la situación actual de la operación, calidad y cantidad de agua de manantiales de la cuenca. En total se identificaron 52, de los cuales se aforaron 49 que aportaron un gasto acumulado de 8.526 m3/s. Las aguas son aprovechadas principalmente para fines agrícolas, consumo urbano, acuacultura y recreativo. El volumen de agua anual que se genera por los manantiales es de 268 876 Mm3, lo que satisface ampliamente las necesidades de la región. La calidad química de los manantiales es excelente para los distintos usos, no así la calidad bacteriológica. En términos de su estado de conservación y operación, sólo el 27 % de ellos, presenta problemas serios de un manejo eficiente, lo que pone en riesgo su sustentabilidad.

The concept of aquifer vulnerability is defined as the probability of groundwater contamination by any substance in concentrations above the values established in the official Mexican Norms for drinking water or the values recommended by the World Health Organization. Although the concept was initially related to qualitative contamination aspects, nowadays it can include quantitative elements, by applying various methods. The main aim of this study was to determine the levels of aquifer vulnerability to ground-water in the Duero river watershed, Michoacán, by using the SINTACS method. The watershed is located northwest of the state of Michoacán, at the Hydrological Region No. 12, Lerma-Santiago, specifically in the Río Lerma-Chapala Hydrologic Area. In the region, volcanic sedimentary environment prevails, highlighting stratovolcano type structures, as well as alluvial and lacustrine deposits. The hydraulic behavior of the basin aquifers varies from free to semi-confined. The economy is based on the production of berries, a cultivation highly water demanding, aspects that promotes groundwater extraction by operating approximately 805 wells, and generating overexploitation in the main valleys. We determined two principal vulnerability levels: (1) low, 80-105 points, covering most of the watershed (50 %) and associated with semi-confined aquifer conditions and related to low hydraulic conductivity clay materials and (2) medium (105-140 points) in 25 % of the surface for aquifers in free hydrogeological condition, associated with alluvial deposits. Very low and high vulnerabilities were detected in few zones. Information focused on this area, helps the establishment of public policies for the protection of groundwater, by zoning potential sites to be contaminated as results of unplanned anthropogenic activities.

El concepto de vulnerabilidad acuífera se define como la probabilidad de que el agua subterránea se contamine con alguna sustancia en concentraciones por arriba de la normatividad para agua de consumo humano o de los valores recomendados por la Organización Mundial de la Salud. Aunque inicialmente se le relacionaba sólo a aspectos cualitativos de contaminación, actualmente puede incluir aspectos cuantitativos, mediante la aplicación de diferentes métodos. El objetivo de este estudio, fue determinar los niveles de vulnerabilidad acuífera para el agua subterránea en la cuenca del río Duero, Michoacán, mediante la utilización del método SINTACS. La cuenca, se localiza al noroeste del estado de Michoacán, dentro de la Región Hidrológica No. 12, Lerma-Santiago, específicamente en la Zona Hidrológica Río Lerma-Chapala. En la región, prevalece un ambiente volcánico sedimentario, destacando estructuras de tipo estratovolcán, depósitos aluviales y lacustres. La economía se sustenta en la producción de frutillas, muy demandante del recurso agua, lo cual hace que la extracción de agua subterránea se realice mediante la operación de aproximadamente 805 pozos, generando sobrexplotación en los valles principales. El comportamiento hidráulico de los acuíferos en la cuenca varía de libre a semiconfinado. Se determinaron primordialmente dos niveles de vulnerabilidad: baja, en el rango de 80-105 puntos, que cubre la mayor parte de la cuenca (50 %) y que se asocia con un acuífero en condiciones de semiconfinado constituido por los materiales arcillosos de baja conductividad hidráulica; y vulnerabilidad media (105-140 puntos) con el 25 % del área, para acuíferos en condición hidrogeológica de libres, asociados a depósitos aluviales. Sólo existen pequeñas porciones con vulnerabilidad muy baja y alta. La obtención de información enfocada hacia este ámbito, coadyuva en el establecimiento de políticas públicas orientadas a la protección del agua subterránea, zonificando sitios potenciales a ser contaminados por actividades antrópicas no planificadas