Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

A retrospective–prospective research was carried out to establish a soil quality index (SQI) of Los Rios region (RR), Tabasco, Mexico, and its modeling with the near infrared technology (NIR) and chemometrics. The SQI was determined with the OM / (clay + silt) relationship to evaluate the Cambisol soils of RR. The OM percentage and the SQI were compared to define the best soil quality qualifier. Based on the SQI, 58% of the soils in RR exhibit degradation, while only 14% indicates a low concentration of OM. Therefore, we conclude that the SQI is more sensitive to quantify soil degradation compared to the evaluation based on OM. A sustainable soil management program and soil practices adapted to local environmental, social and economic conditions are recommended to increase OM and improve SQI. With the SQI, a classification model was established using near-infrared spectroscopy and chemometrics. The spectra of each soil sample were recorded and through chemometric interpretation, it was shown that it is possible to conduct a partial least squares discriminant analysis model (PLS-DA) to predict the SQI. The model meets all statistical qualifiers and correctly predicts the SQI in 100% of cases. We conclude that the NIR technology provides suf ficient information to predict the SQI with the advantage of eliminating the consumption of reagents, no laboratory waste is generated, the analysis time is reduced to minutes, and the sample under study is not destroyed. In addition, the procedure is simple as it consists of drying, grinding and sieving the soil samples to assess the structural quality of the soil.

Nitrogen is the most important nutrient for forage crops because of its contribution in various biochemical reactions in the dif ferent phenological stages of the plant. The main aim of this study is to develop a multiple linear regression model to estimate total nitrogen (Nt) in corn plants using spectral indexes. The percentage of total nitrogen (Nt) was determined through three plant samplings in four experimental plots. The estimation model was obtained to process the Sentinel-2 satellite images according to the plant sampling dates; 13 spectral indexes were calculated and the association between nitrogen and the reflectance values was analyzed by the principal component analysis (ACP), correlation matrix, and dendrogram. The indexes with the highest relationship were MCARI / OSAVI, TCARI / OSAVI, MCARI / OSAVI RE and TCARI / OSAVI RE, explaining more than 50% of the variability of the proposed model and a MSE of 0.12. This study indicates that the estimation obtained from Sentinel-2 spectral indexes images has great potential to determine nitrogen in crops. However, for future research, Nt estimation models should be obtained for each phenological crop stage.

The use of digital soil mapping allows obtaining quantitative information on soil distribution and functioning to provide alternatives for their management. The objective of this research is to perform the spatial prediction of soil properties through regression-kriging and serve as a basis for taking the necessary measures for a sustainable use of the resource. The study area is located in the wetland Cienaga de Chapala portion of Michoacán, Mexico. Soil sampling was systematic. In the laboratory, electrical conductivity, organic carbon, soluble cations calcium, potassium, magnesium, sodium (Ca, K, Mg, Na), total nitrogen and pH were determined for each soil sample. The dependent variables were total nitrogen, electrical conductivity, organic carbon and pH. The independent variables are the Landsat 8 satellite bands. Regression-kriging was applied for spatial prediction. The experimental semivariogram fit with theoretical models was consistent for the four soil properties, because it was a systematic sampling design and the sample size was 297 points. The root mean square error of the electrical conductivity spatial prediction was 4 because it showed a coefficient of variation of 355. Soils are considered having from low to very low total nitrogen content (<0.15%). At least 30% of the soils have salinity problems because their electrical conductivity is greater than 1.1 dS m-1. Organic carbon contents are considered medium to high (>0.6%). The pH of the soils is moderately alkaline.

Mexico’s New International Airport megaproject was announced for the first time in 2001 and canceled in 2019; however, most of its construction progress took place during 2012-2018. With its announcement and cancellation there was a land use change and speculation regarding the land value. This study evaluates the impact that the airport construction and cancellation had over land use change in the municipality of Texcoco and neighboring municipalities in Mexico State, and the perception of key players concerning its effects. High-resolution images from the Sentinel-2 satellite were processed for the years 2016 to 2021. Geographic information systems were used to carry out a supervised classification with spectral indices and generate thematic maps of land use with four classes: bare soil, vegetated soil, urban land and water bodies. Interviews were applied to key players for a qualitative analysis of the appreciation of changes and effects derived from the airport project. Results show a higher growth rate of urban land from 2016 to 2017, mainly close to the airport building, replacing mostly bare soil. The airport caused discontent in the population by its environmental effects and social consequences, such as problems due to freight vehicles traffic. As a result of the airport cancellation, there is bare ground caused by mine exploitation and vehicular insecurity due to incomplete roads.

The low ef ficiency of cocoa vegetative propagation from cuttings requires the use of rooting agents. This situation motivated a study whose objective is to optimize the oligogalacturonide dose on the vegetative propagation of two cocoa clones under controlled conditions in the nursery. The source of oligogalacturonides was provided in doses: 0, 10, 50 and 100 mg L-1 compared to the chemical rooting (composed of: 7% nitrogen, 45% phosphorus, 5% potassium, 0.1% boron, 3% metabolic activators and 10% marine algae), which was applied by immersion at the base of the cutting. The clones tested were CCN-51 and EET-801. The evaluated variables were: number of leaves and roots, radical fraction, fresh biomass of leaves and roots, dry biomass of leaves, roots, and stem and index of regenerated plants. The results indicated that the doses of 50 and 100 mg L-1 showed the greatest ef fects on the number of leaves (NH), radical fraction (FR), dry biomass of the leaf (DSB) and stem (DST). Clone CCN-51 showed higher NH, FR, BSH and BST than EET-801 (P < 0.05). In number of roots (NR), fresh root biomass (BFR), dry root biomass (DRB), fresh leaf biomass (BFH) and the index of regenerated plants (IPR), the clones were the same. The IPR had a positive correlation with the other variables (P < 0.05). Using 85 mg L-1 of chemical rooting an IPR of 49.1% can be achieved. The IPR can be predicted based on the variables BFR and BFH with R2 = 0.96.

The salinity of soils and water for irrigation is a limitation that influences the productivity of crops that has increased worldwide and af fects the morphology and physiology of plants since it causes osmotic stress and ionic toxicity and impairs the absorption of water and nutrients. The ef fect of salt stress on some morphological and physiological traits in Coccoloba uvifera (L.) L. (sea grape) seedlings from dif ferent origins was evaluated and the traits whose behavior under salt stress could be used as an ef fective criterion of tolerance to salinity were determined. A completely randomized design experiment with ten repetitions was performed. The factors under study were salinity (0, 5, 15, and 25 dS m-1), which was maintained for a period of sixteen weeks, and the second factor was the origin of the plant material. The salinity level and the seedlings’ origin significantly influenced the morphological and physiological variables controlled. However, it is necessary to carry out in situ experiments to obtain more information related to the mechanisms used by sea grape to tolerate salinity conditions, because in the consulted sources no research focused on evaluating the ef fect of salinity and the origin on the morphology and physiology of C. uvifera seedlings in Cuba has been found. The results of the research provide preliminary information to understand the negative ef fect of salt stress on this type of plant. The behavior of some controlled traits under salt stress can be used as an ef fective criterion of tolerance to salinity.

The rhizosphere of the great diversity of plants is a complex ecosystem that houses thousands of rhizobacteria that promote plant growth. In the current investigation, three bacteria were isolated from the root of Suaeda sp., which were evaluated to determine the ef fect of their inoculation on Arabidopsis thaliana at distances of 2 and 5 cm and in divided boxes. In the 2 cm test, we noticed that Endo10(7) and Endo10(5) stimulated the plants more than the control, while the proximity to Ecto10(6) caused them to wilt and die. However, at 5 cm, the bacterium that most promoted the development of Arabidopsis was Ecto10(6). In the divided box test, all three bacteria showed the ability to promote growth. In addition, a shade mesh assay was carried out with the inoculation of the bacteria in Solanum lycopersicum L. (Sahariana) and it was found that the promoting ef fect was also observed in the germination and growth of tomato plants. Tests were conducted to determine its ability to produce IAA, siderophores, and solubilize phosphates. Through molecular techniques it was confirmed: the identity of Ecto10(6), Endo10(7), and Endo10(5) as Aneurinibacillus migulanus, Staphylococcus sp. and Bacillus cereus, respectively. Our results provide the rationale for suggesting that these rhizobacteria may increase the growth and development of Arabidopsis thaliana and Solanum lycopersicum.

El presente número integra manuscritos implementados por científicos investigadores de la Universidad del Mar, campus Puerto Escondido, así como de instituciones de relevancia nacional como el Colegio de Postgraduados, la Universidad Autónoma de Nayarit y la Universidad de Guadalajara. Las contribuciones que se presentan, muestran el interés de los científicos en el estudio de la calidad química de las aguas superficiales de algunas cuencas de importancia nacional, la salinidad de los suelos, la evaluación de la tolerancia a sales de algunos pastos costeros como alternativa para la producción de forraje, las características fenológicas y crecimiento de especies nativas en conservación de la selva baja caducifolia, alternativas de alimentación de ganado con especies vegetales forrajeras, así como, la disponibilidad de establecer manchones arbóreos en suelos salinos del Ex Lago de Texcoco, México. Estas contribuciones integran datos experimentales de campo que muestran conclusiones validas sobre la respuesta de los fenómenos. De igual manera, proponen alternativas de uso y manejo del suelo del agua y la vegetación que persiguen la conservación de los ecosistemas y la generación del bienestar socioeconómico de las comunidades rurales que integran las áreas de estudio. Esperando lograr la inquietud cognoscitiva del público en general. Con especial reconocimiento al Dr. Edgar Iván Sánchez Bernal (1963 - 2022) por su incansable estudio a favor de los suelos de la costa de Oaxaca.

The media operate under a specific value system. This work, carried out between 2021 and 2022, attempts to understand how the Argentine Pampas press produces and reproduces social representations that strengthen the beliefs and practices of a group of young men who use a psycho-socio-educational care device for men convicted of domestic violence. gender. Discourse Analysis was used, whose methodology allowed making a clipping of the Pampas written press and the speeches of the users of the device. Thus discussing the influence that the former have over the latter in terms of reinforcing violence.