oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 374 )

2018 ( 531 )

2017 ( 539 )

2016 ( 768 )

Custom range...

Search Results: 1 - 10 of 331813 matches for " Ignacio Sánchez Cohen "
All listed articles are free for downloading (OA Articles)
Page 1 /331813
Display every page Item
Increasing Water Use Efficiency in Husk Tomato (Physalis ixocarpa Brot) Production in Tabasco, Mexico with Improved Irrigation Water Management  [PDF]
Rutilo López-López, Ignacio Sánchez Cohen, Marco Antonio InzunzaIbarra, Andrés Fierro álvarez, Gerardo Esquivel Arriaga
Journal of Water Resource and Protection (JWARP) , 2014, DOI: 10.4236/jwarp.2014.613114
Abstract: Husk tomato production technology was developed utilizing plastic sheeting and drip irrigation based on the results of reference evapotranspiration and crop coefficients (Kc) proposed at different phenological stages. The objectives of this study were as follows: 1) to evaluate the effect of plastic sheeting on the yield of husk tomato fruit with drip irrigation based on crop evapotranspiration; 2) to validate the use of drip irrigation technology and plastic sheeting in husk tomato production using demonstration plots; and 3) to determine the profitability and economic viability of the product in the domestic market. The proposed Kc values were 0.25, 0.71 and 0.56 in the initial, intermediate and final stage of crop development, respectively. Irrigation rates ranged from 2.5 to 6 mm·day-1, which was equivalent to an irrigation time of 0.6 to 2.5 hr. Soil moisture tension was monitored with tensiometers at depths of 15 and 30 cm in a loamy eutricfluvisol. The use of plastic sheeting increased husk tomato yield by 56.2% and water productivity by 63.5% under drip irrigation conditions when basing irrigation levels on crop evapotranspiration. Soil matrix potential varied between depths of 15 and 30 cm based on irrigation or rainfall amounts and the use of plastic sheeting with values being higher when the plastic sheeting was used. The husk tomato fruit yield in validation plots was 46 and 54.6 t·ha-1 with water use efficiencies ranging from 16.1 to 19.1 kg·m-3. These results exceeded the national average of 14 t·ha-1 and water use efficiency of 2.54 kg·m-3. With this new technology, a cost benefit ratio of 3.6 is obtained, which represents an economically profitable margin for farmers in the region.
Proceso jerárquico analítico para la toma de decisiones en el manejo de los recursos naturales
Sánchez Cohen, Ignacio;Díaz Padilla, Gabriel;Macías Rodríguez, Hilario;Estrada ávalos, Juan;
Revista mexicana de ciencias agrícolas , 2010,
Abstract: the multiobjective and multicriteria vision helps identify agreed actions with common benefits and shared commitments in decision making, for the conservation of natural resources. the aim of this study was to propose an analysis model for the management of natural resources in the basin of lobos, in the municipality of leon, guanajuato; which could be applied to any basin in the country in 2008. the alternative topics of action proposed by the participants and users of the basin interviewed were: organization, environmental services, training, culture, reforestation, rational ordering and law abiding, which were analyzed based on economic, technical, social and environmental criteria. the results showed that the alternative "culture", followed by rational arrangement and law abiding were the most significant. the ecological criterion was a large contribution for "culture" to be the most important alternative. the influence of technical and economic criterion was limited, due to the relatively low importance assigned.
Proceso jerárquico analítico para la toma de decisiones en el manejo de los recursos naturales Analytical hierarchical process for decision taking in natural resources management
Ignacio Sánchez Cohen,Gabriel Díaz Padilla,Hilario Macías Rodríguez,Juan Estrada ávalos
Revista mexicana de ciencias agrícolas , 2010,
Abstract: La visión multiobjetivo y multicritero permite identificar acciones consensuadas de beneficio común y compromisos compartidos en la toma de decisiones, para la conservación de los recursos naturales. El objetivo del trabajo fue proponer un modelo de análisis multiobjetivo desarrollado para el manejo de los recursos naturales en la cuenca de Lobos del municipio de León, Guanajuato; que puede ser extrapolado a cualquier cuenca del país en 2008. Los temas alternativos de acción propuestos por los participantes y usuarios de la cuenca entrevistados fueron: organización, servicios ambientales, capacitación, cultura, reforestación, ordenamiento racional y cumplimiento de la ley, los cuales se analizaron con base en criterios económicos, técnicos, sociales y ecológicos. Los resultados mostraron que la alternativa "cultura", seguida de ordenamiento racional y cumplimiento de la ley fueron las más significantes. El criterio ecológico aportó alta contribución para que "cultura" fuese la alternativa más importante. La influencia de los criterios técnico y económico fue limitada debido a la baja importancia relativa asignada. The multiobjective and multicriteria vision helps identify agreed actions with common benefits and shared commitments in decision making, for the conservation of natural resources. The aim of this study was to propose an analysis model for the management of natural resources in the basin of Lobos, in the municipality of Leon, Guanajuato; which could be applied to any basin in the country in 2008. The alternative topics of action proposed by the participants and users of the basin interviewed were: organization, environmental services, training, culture, reforestation, rational ordering and law abiding, which were analyzed based on economic, technical, social and environmental criteria. The results showed that the alternative "culture", followed by rational arrangement and law abiding were the most significant. The ecological criterion was a large contribution for "culture" to be the most important alternative. The influence of technical and economic criterion was limited, due to the relatively low importance assigned.
Indicadores comparativos del uso del agua en la agricultura
Sánchez Cohen, Ignacio;Catalán Valencia, Ernesto;González Cervantes, Guillermo;Estrada Avalos, Juan;García Arellano, David;
Agricultura técnica en México , 2006,
Abstract: the evaluation of productivity of the natural resources is an essential task for promoting its sustainability and optimal use. the overall objective of this study was to expose the relevance of the use of efficiency and vulnerability indexes for the use of water in agricultural systems under irrigation. a study case is presented regarding the evaluation of crop patterns for the agricultural year 2003 during the spring-summer season and fall-winter 2003-2004 of two irrigation districts in the central-north region of mexico. also, the evaluation of the operation of four irrigation districts is presented. in both cases, indexes developed for the international water management institute were used. we concluded on the utility of these indexes for satisfactory decision taking processes and for clasifing farmers according to their capacity to cope with climatic uncertainty.
Reconstrucción de la precipitación estacional para el barlovento de la Sierra Madre Occidental con anillos de crecimiento de Pseudotsuga menziesii (Mirb.) Franco
Villanueva Díaz, José;Fulé, Peter Z.;Cerano Paredes, Julián;Estrada ávalos, Juan;Sánchez Cohen, Ignacio;
Ciencia forestal en México , 2009,
Abstract: northwest mexico is a leader region in terms of agriculture, but is highly dependant on aquifers and on surface water from watersheds of the sierra madre occidental draining toward the pacific. paleoclimate studies to determine historical hydroclimate variability are rare in this region. two earlywood chronologies of pseudotsuga menziesii were developed for mixed-conifer stands in the sierra madre occidental. one of them is 531 years in length (1472-2002) and is located in tutuaca, chihuahua; the second one located in el cócono, guanaceví, durango, is 554 years length (1449-2002). the earlywood chronologies are significantly related to the seasonal winter-spring precipitation (october-may) and respond similarly (r = 0.61, p<0.00001; period 1472-1999) to precipitation. they detect drought periods of greater intensity than those witnessed during the 20th century. the most intensive and prolonged drought episodes were reconstructed for the 1560s, 1700s, and 1770s. historical archives indicate that some of these droughts were related to famine and epidemic outbreaks. the warm phase of enso has a strong signal in this region and produces above normal precipitation, whereas the cold phase is related to drought. moreover, the enso signal is not stable and changes through time as indicated by the correlation between precipitation and the tropical rainfall index. the development of a greater number of tree-ring chronologies is basic to understand the hydroclimate variability of the warm season (summer), which is of greater hydrological importance.
Variabilidad climática y productividad agrícola en zonas con errático régimen pluvial Climate variability and agricultural productivity in areas with erratic rainfall patterns
Ignacio Sánchez Cohen,Marco Antonio Inzunza Ibarra,Ernesto Alonso Catalán Valencia,José Luis González Barrios
Revista mexicana de ciencias agrícolas , 2012,
Abstract: La alta variabilidad en espacio y tiempo de los regímenes pluviales, hacen que la agricultura en zonas de temporal esté sujeta al riesgo climático. En esta tesitura, la mejor herramienta para sustentar la toma de decisiones lo constituye la modelación hidro-climática en donde se considera lo estocástico de los procesos hidrológicos. En el presente trabajo se hace uso de una serie de algoritmos anidados (AA) para llegar a estimar el rendimiento del cultivo maíz bajo diferentes escenarios climáticos. El algoritmo es calibrado y aplicado a una región de temporal deficiente en el norte de México (Cuencamé, Durango). Se parte de un generador climático (WXPARM) para obtener los parámetros de clima que definen a la región; posteriormente, para cuantificar el impacto del rendimiento del cultivo bajo condiciones de cambio climático, se hace uso de un modelo de reescalado para aplicar los datos de modelos climáticos globales (modelos de circulación general) a nivel parcelario (SDM) y finalmente las matrices que definen las condiciones climáticas mensuales en la región de estudio son utilizadas en un modelo para evaluar el impacto en rendimiento (EPIC) mediante la modelación del balance de humedad en el suelo. Los resultados indican que bajo escenarios de cambio climático, se esperarían incrementos en rendimiento de hasta 0.3 tha-1 dado el cambio en los patrones climáticos esperados en los que se vislumbra un comportamiento bimodal de la lluvia. Acorde al comportamiento del clima en el futuro, sería recomendable el ajuste de fechas de siembra para que los máximos requerimientos del cultivo coincidan con la presencia de lluvias The high variability in space and time of the rainfall patterns, make agriculture in rainfed areas subject to climatic risk. In this situation, the best tool to support decision-making is the hydro-climatic modeling, where the hydrological stochastic processes are considered. In the present study, nested series of algorithms (AA) are used in order to estimate maize crop yield under different climate scenarios. The algorithm is calibrated and applied to a poor rainfed region in northern México (Cuencamé, Durango). It is part of a weather generator (WXPARM) for climate parameters that define the region later to quantify the impact of maize yield under climatic change conditions; using are scaled model to apply global climatic data models (GCMs) at plot level (SDM) and finally the matrices that define the monthly weather conditions in the region of study are used in a model to assess the impact on yield (EPIC) by modeling the balance of moistur
Reconstrucción de 350 a?os de precipitación para el suroeste de Chihuahua, México
Cerano Paredes, Julián;Villanueva Díaz, José;Fulé, Peter Z.;Arreola ávila, Jesús Guadalupe;Sánchez Cohen, Ignacio;Valdez Cepeda, Ricardo David;
Madera y bosques , 2009,
Abstract: earlywood, latewood, and total ring width series from pseudotsuga menziesii were developed in a mixed conifer forest at cerro el mohinora", chihuahua. the tree-ring series extended for the period 1657-2005 (349 years) and were used to analyze hydroclimatic variability for southwestern chihuahua. a seasonal winter-spring precipitation reconstruction was developed with the objective to determine high and low frequency precipitation variability and to analyze the impact of dominant atmospheric circulatory patterns. the reconstruction indicated high interannual, decadal and multiannual variability. severe droughts were reconstructed for the periods 1695-1715, 1753-1760, 1785-1792, 1798-1806, 1819-1830, 1841-1870, 1890-1897, 1906-1912, 1924-1941, 1971-1977, and 1994-2005. the most extended droughts took place in the periods 1695-1715, 1841-1870, and 1924-1941. the last three decades of the 20th century and the current years of the 21st century have been particularly dry for northwestern chihuahua but the ecological and socieoconomical impacts have not been determined.
índice de estrés hídrico como un indicador del momento de riego en cultivos agrícolas
López López, Rutilo;Arteaga Ramírez, Ramón;Vázquez Pe?a, Mario Alberto;López Cruz, Irineo;Sánchez Cohen, Ignacio;
Agricultura técnica en México , 2009,
Abstract: crop water stress index (cwsi) is based on the determination of the actual crop transpiration rate by means of the measurements of canopy temperature and vapor pressure deficit. the objectives of this assay were: to present theoretical and methodological aspects of cwsi and its practical application for irrigation scheduling. the cwsi method has been of practical use in arid and semiarid regions mainly because the required equipment to calculate it is easy to use. this method can also be utilized in humid regions where irrigation is needed during the dry season and there is high solar radiation. the cwsi is based on the theory of energy balance on a surface, the linear functions of the differential temperature between the crop and the air and the vapor pressure deficit; which depends on the crop water status and the weather conditions. infrared thermometry is a simple, practical and reliable tool to estimate crop water stress, irrigation scheduling and yield prediction.
Interpolación espacial de la precipitación pluvial en la zona de barlovento y sotavento del Golfo de México
Díaz Padilla, Gabriel;Sánchez Cohen, Ignacio;Quiroz, Roberto;Garatuza Payán, Jaime;Watts Thorp, Christopher;Cruz Medina, Isidro Roberto;
Agricultura técnica en México , 2008,
Abstract: this study was conducted in the digital agro-maps laboratory of the central gulf region of the national research institute for forestry, agriculture and livestock in 2007. the objective was to compare four rain interpolation methods using the historic precipitation data of september from the period 1961 to 2003 of 147 climatic stations belonging to the national weather service. these stations cover a region of the windward and leeward direction in mexico. in order to define a suitable method, four interpolation methods were compared: inverse of the distance, krigging, co-krigging and thin plate smoothing spline. data was analyzed to define if there is relationship of rainfall with altitude, longitude and distance from the ocean. the method of thin plate smoothing spline was superior since it gave the lowest mean square error followed by the method of krigging and co-krigging using gaussan method. it is important to mention that with the co-krigging method, altitude was used as a covariate despite that there was not a strong correlation of this variable with precipitation. the last option for rainfall data interpolation was the inverse of the distance with optimized values.
Respuesta de la canola al déficit hídrico del suelo
Inzunza Ibarra, Marco A.;Catalán Valencia, Ernesto A.;Villa Castorena, Magdalena;Sánchez Cohen, Ignacio;Román López, Abel;
Revista fitotecnia mexicana , 2010,
Abstract: this work was carried out at gómez palacio, durango, méxico. the goal of the study was to find a production function for relating canola (brassica napus l.) yield with soil water content. seven irrigation treatments were applied, of which six were levels of residual available soil moisture depletion (0, 12, 24, 36, 48 and 60 %), and a treatment of one irrigation applied before sowing. the experiment was a complete randomized block design with four replications. the measured variables were grain yield, water use efficiency and water crop consumption. according to the production function obtained, it is possible to reach a grain yield of 3.1 t ha-1, with a water depth of 48 cm by irrigating at 35 % of residual soil available water, equivalent to a soil water tension of -0.74 mpa.
Page 1 /331813
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.