1,463 research outputs found
Views on sustainability and the willingness to adopt an environmental management system in the Mexican vegetable sector
In Mexico, agriculture’s main environmental problems are related to water resources, deforestation and soil erosion. These problems are more acute in arid or semiarid regions such as in the state of Zacatecas. Environmental management systems (EMS) can be an alternate means for improving environmental conditions. In this study, factors that determine willingness to adopt an EMS in the vegetable production units of the state of Zacatecas were identified. We also analysed views on sustainability and production practices oriented toward environmental management and care of natural resources, as well as drivers and barriers to EMS adoption. Factors determining EMS adoption were level of education, awareness of the importance of caring for and protecting natural resources, application of agricultural practices oriented toward protecting the environment, and ignorance of environmental problems
Selecting strains of arbuscular mycorrhizal fungi in two production systems of chili pepper
The selection of native microorganisms of a region for biofertilizer production, gives higher possibilities of adaptation and multiplication thereof on the ground, because, among these, functional diversity of arbuscular mycorrhizal fungi (AMF) may depend on the origin of the isolates, rather than the fungal species. With the aim of selecting AMF native strains isolated from soil of two production systems of Mirasol chili pepper: technified (TEC) and traditional (TRA); as trap crop for selecting AMF Mirasol chili pepper seedlings which were inoculated with soil and TRA and TEC and a non-inoculated control, for selecting parameters were considered infectivity and effectiveness. Stablishing in a greenhouse 14 treatments with TEC and 15 with TRA, each with eight repetitions. For 40 days, the variable plant height and dry biomass were measured (leaves, stem, root and total), the percentage of root colonized at 90 days after transplantation was also evaluated. The TEC-11 and TRA-14 were those with the treatments most consistent by measured parameters, they had a total dry biomass production of (0.66 and 0.69 g, respectively), with percentage of root colonization (and 33.89 36.67, respectively).La selección de microorganismos nativos de una región para la producción de biofertilizantes, da mayores posibilidades de adaptación y multiplicación de los mismos en el suelo, debido a que, entre éstos, la diversidad funcional de los hongos micorrízicos arbusculares (HMA) puede depender de la procedencia de los aislamientos, más que de la especie fúngica. Con el objetivo de seleccionar cepas nativas de HMA aisladas de suelos de dos sistemas de producción de chile Mirasol: tecnificado (TEC) y tradicional (TRA); como cultivo trampa para la selección de HMA se utilizaron plántulas de chile Mirasol las cuales fueron inoculadas con suelo TEC y TRA y un testigo sin inocular, para la selección se consideraron parámetros de infectividad y efectividad. Se establecieron dentro de un invernadero 14 tratamientos con TEC y 15 con TRA, cada uno con ocho repeticiones. Durante 40 días se midió la variable, altura de planta y biomasa seca (hojas, tallo, raíz y total), también se evaluó el porcentaje de raíz colonizada a los 90 días después del trasplante. Los tratamientos TEC-11 y TRA-14 fueron los que presentaron los resultados más consistentes en los parámetros medidos, tuvieron una producción de biomasa seca total de (0.66 y 0.69 g, respectivamente), con porcentaje de colonización en la raíz de (33.89 y 36.67, respectivamente)
Oscillation tomografy study of Earth's composition and density with atmospheric neutrinos
Knowledge of the composition of the Earth's interior is highly relevant to
many geophysical and geochemical problems. Neutrino oscillations are modified
in a non-trivial way by the matter effects and can provide valuable and unique
information not only on the density but also on the chemical and isotopic
composition of the deep regions of the planet. In this paper, we re-examine the
possibility of performing an oscillation tomography of the Earth with
atmospheric neutrinos and antineutrinos to obtain information on the
composition and density of the outer core and the mantle, complementary to that
obtained by geophysical methods. Particular attention is paid to the D layer just above the core-mantle boundary and to the water (hydrogen)
content in the mantle transition zone. Our analysis is based on a Monte-Carlo
simulation of the energy and azimuthal angle distribution of -like events
generated by neutrinos. Taking as reference a model of the Earth consisting of
55 concentric layers with constant densities determined from the PREM, we
evaluate the effect on the number of events due to changes in the composition
and density of the outer core and the mantle. To examine the capacity of a
detector like ORCA to resolve such variations, we construct regions in planes
of two of these quantities where the statistical significance of the
discrepancies between the reference and the modified Earth are less than
. The variations are implemented in such a way that the constraint
imposed by both the total mass of the Earth and its moment of inertia are
verified.Comment: Already published in the European Physical Journal
Assessing Environmental Management of Tomato Production under Protected Agriculture
This study examines the impact of environmental strategies on profitability of protected agriculture production systems in the state of Zacatecas, Mexico using the approach of Total Quality Environmental Management (TQEM) and Total Cost Assessment (TCA). We identified environmental management practices currently used by production units and analyzed the existing situation, plus two hypothetical scenarios. Profitability indicators show that adopting conservation production practices will not only improve the image of the organization but permit better access to markets, maintain positive profitability and contribute to the conservation of natural resources
Total cost assessment of greenhouse tomato production in Zacatecas, Mexico
Agriculture in the state of Zacatecas, Mexico, consumes 77% of the available groundwater. In this region, the main source of water is 34 aquifers, of which 44% are over exploited. Over extraction of the aquifers damages the environment, increases pumping costs and decreases water quality. Greenhouse tomato production systems have increased considerably in recent years. Besides the environmental problems that agriculture generates, there is also the problem of emissions and solid waste. The objective of this paper is to assess the environmental impact on profitability of protected agriculture systems in the state of Zacatecas. The methodology used was total cost assessment. This study assesses the total cost of four production units in their present situation, as well as in two scenarios: one denominated sustainable and the other unsustainable. Profitability indicators in the sustainable and unsustainable scenarios show that adopting conservation production practices, besides improving the image of the organization and permitting better access to markets, will maintain profitability and contribute to the conservation of natural resources
Earth tomography with atmospheric neutrino oscillations
The study of the flux of atmospheric neutrino crossing the Earth can provide useful information not only on the matter density of the different layers that make up the planet but also on their chemical composition. The key phenomenon that makes this possible is flavor oscillations and their dependence on the electron density along the neutrino baseline. To extract the relevant information, we simulate the energy and azimuth angle distribution of events produced in a generic neutrino telescope by atmospheric neutrinos passing through the deepest parts of the Earth. Changes in the densities of the outer core and the mantle are implemented by varying the location of the boundary between these layers so that the restrictions on the mass of and the moment of inertia of the Earth are both satisfied. This allows us to examine the effect of simultaneous changes in composition and density of the outer core, unlikely other works on the subject, where only one of these quantities was varied.Fil: D'Olivo, Juan Carlos. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Herrera Lara, José Arnulfo. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Romero, Ismael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Sampayo, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Zapata, Gabriel Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin
Evaluation of Different Concentrations of Nitrogen for Tomato Seedling Production (Lycopersicon esculentum Mill.)
This study was aimed at evaluating the
different concentrations of nitrogen for tomato seedling
production (Lycopersicon esculentum Mill.), hybrid Loreto.
Five concentrations of nitrogen were analyzed: 0, 4, 8, 12
and 16 mEq / L, using as a basis the Steiner nutrient solution.
A pilot randomized block design was used with six
replications and five treatments. Thirty-five days after
sowing, the following variables were analyzed: seedling
height, stem diameter, fresh stem weight, fresh leaf weight,
leaf area, dry steam weight, dry leaf weight, dry root weight
and total nitrogen content. An ANOVA analysis (p <0.05)
with post-hoc Tukey test was performed to compare each
treatment variables. The results showed that the increase in
the concentration of nitrogen has a positive effect on organ
growth. The treatment with the highest values in the
morphological variables was 16 mEq / L, which shortened
the production time of seedlings ready for transplant
Evaluation of Different Concentrations of Nitrogen for Tomato Seedling Production (Lycopersicon esculentum Mill.)
This study was aimed at evaluating the
different concentrations of nitrogen for tomato seedling
production (Lycopersicon esculentum Mill.), hybrid Loreto.
Five concentrations of nitrogen were analyzed: 0, 4, 8, 12
and 16 mEq / L, using as a basis the Steiner nutrient solution.
A pilot randomized block design was used with six
replications and five treatments. Thirty-five days after
sowing, the following variables were analyzed: seedling
height, stem diameter, fresh stem weight, fresh leaf weight,
leaf area, dry steam weight, dry leaf weight, dry root weight
and total nitrogen content. An ANOVA analysis (p <0.05)
with post-hoc Tukey test was performed to compare each
treatment variables. The results showed that the increase in
the concentration of nitrogen has a positive effect on organ
growth. The treatment with the highest values in the
morphological variables was 16 mEq / L, which shortened
the production time of seedlings ready for transplant
Nitrogen determination on tomato (Lycopersicon esculentum Mill.) seedlings by color image analysis (RGB)
In order to investigate the effectiveness of a new method based on color image analysis and the Minolta SPAD-502 chlorophyll meter for the diagnosis of nitrogen deficiencies of tomato seedlings, a field experiment was conducted. In this study, five levels of nitrogen fertilization were established so as to induce nitrogen deficiencies in tomato seedlings. Thirty-five days after sowing, total nitrogen was evaluated by laboratory analysis. The chlorophyll index was determined using a SPAD-502 chlorophyll meter. Also, color images were taken with a digital camera; the color images were processed in MATLAB in order to determine the averages of the red color, green color and the blue color. The relationships between variables were analyzed by linear regressions and a one way analysis of variance (p < 0.01). Results showed that color image analysis correlated better with the status of plant nitrogen than the SPAD. From the color image analysis, the red and blue colors were more accurate predictors of nitrogen status on plants with R2 above 0.89. Color image analysis provides an accurate and quick way for nitrogen estimation and can contribute for early detection of nitrogen deficiency in tomato seedlings. The SPAD method is not a reliable way to estimate the nitrogen status on tomato seedlings.Keywords: Color image analysis (RGB), chlorophyll meter, nitrogen deficiencyAfrican Journal of Biotechnology Vol. 9(33), pp. 5326-5332, 16 August, 201
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