The benefits of mycorrhizal interactions are only known in 8 of 210 recognized Agave taxa. We evaluated the effects of autochthonous and allochthonous arbuscular mycorrhizal fungi (AMF) on growth and nutrient assimilation in Agave maximiliana. The autochthonous consortium (Cn) of eight species was propagated from the rhizospheric soil of A. maximiliana, while Claroideoglomus claroideum (Cc) and Claroideoglomus etunicatum (Ce) were employed as allochthonous AMF. Six treatments were included in the study: Cn, Ce, Cc, Ce + Cc, Tf (fertilized control), and Tn (non-fertilized control, not inoculated). Mycorrhizal colonization increased over time, and the colonization percentages produced by Cn and the allochthonous AMF, both alone and mixed together, were equal at 6, 12, and 18 months. Height increased steadily and was higher in AMF-treated plants from seven months onward. Growth indicators of AMF-treated and AMF-free plants were equal at 6 months, but the beneficial effects of allochthonous and autochthonous AMF were evident in all growth indicators at 18 months and in sugar and mineral (P, K, Ca, Mg, and Fe) content. Arbuscular mycorrhizal fungi significantly improved all growth parameters of A. maximiliana regardless of the origin of the inoculums. This is the first study to report the positive effects of AMF colonization in A. maximiliana.

Knowledge of native Arbuscular Mycorrhizal Fungi (AMF) and their relationship with the edaphic characteristics where they live is important to establish the influence of allochthonous AMF, which were inoculated, on the development and stability of soil aggregates. The objectives of this research were to know the composition of native AMF species from two contrasting soils, and to establish the development and stability of aggregates in those soils with corn plants after inoculating them with allochthonous AMF. The experiment had three factors: Soil (two levels [S1 and S2]), HMA (three levels: without application [A0], with the application of Claroideoglomus claroideum [A1] and with the application of a consortium [A2]) and Fertilization (two levels (without fertilization [f0] and with fertilization [f1])). Twelve treatments were generated, with five replicates (60 experimental units [EU]). The EU consisted of a pot with a corn plant and the distribution was completely random. The results demonstrated that the Typic Ustifluvent presented nine species of native AMF, while the Typic Dystrustert had three; the native AMF in each soil influenced the activity of allochthonous AMF, such as their colonization and sporulation. Likewise, differences were found in the stability of macro-sized aggregates (0.5 to 2.0 mm).

Emerging or alternative crops are those that have been recently introduced in response to new demands and commercial opportunities. The fig has been introduced as an alternative fruit crop in Mexico due to its high nutritional, nutraceutical, and antioxidant capacity. A total of 644 points of presence were downloaded and filtered according to climatic ranges and agricultural areas, leaving 68 records. The MaxEnt algorithm was used to develop the habitat suitability models for current and future climate. The bioclimatic variables of the global circulation models, Hadley Centre Global Environment Model version 2-EarthSystem (HADGEM2-ES) and Max Planck Institute for Meteorology-Earth System Model Low Resolution (MPI-ESM-LR), were used under scenarios 2.6 and 8.5. The changes in the fig area for Mexico were analyzed based on the generated models. Under the current climate, 359,575.76 km² were estimated for 2050, and a loss of area for the excellent category was estimated for both models and scenarios; however, for the MPI-ESM-LR model projected to 2070, an increase of 5.51% and 0.39% was estimated for scenarios 2.6 and 8.5, respectively. The effect of climate change on agronomic species such as figs will be expressed in variations in climatic ranges and areas suitable for their development. The results of this study reveal the negative and positive effects of climate change on fig habitat suitability in Mexico. The dynamics of changes in surface area will be reflected mainly in northern and central Mexico.

Indole-3-acetic acid (IAA) concentration is directly proportional to the amount of vermicompost (VC) added to sand substrates. The objectives of this work were to establish the effect of the amount of VC in sand substrates on the concentration of IAA and to determine its influence on tomato plants. Sand substrates with VC percentages (0, 20, 40, and 50%) were placed in pots; in each one, the concentration of IAA was determined at the beginning and the end (after supporting tomato plants), and its bacterial load was determined. In tomato plants, some vegetative and yield components were measured. The results show that by adding 1 kg of VC in a sand-based substrate, the concentration of exogenous IAA increases by 0.0470 and 0.0642 mg g⁻¹ (at the beginning and the end, respectively). This increase was reflected in the development of the plants; for example, their roots demonstrated their maximum development (370.20 cm⁻³) when the amount of VC in the substrate was 3.95 kg. Therefore, the amount of VC used in the preparation of substrates influences the concentration of IAA in them, which is reflected in the development of tomato plants.

En la Comarca Lagunera que comprende parte de los estados de Coahuila y Durango, México. Se ubica la principal cuenca lechera del país. Por lo tanto, el establecimiento de cultivos forrajeros ejerce la mayor presión para la explotación de los recursos hídricos en esta región. Lo anterior, genera la necesidad constante de adaptar y modificar los sistemas de producción actual. El objetivo de esta investigación fue evaluar la producción de maíz forrajero mediante el uso de plásticos acolchados en un sistema de riego con cintilla. Se evaluaron tres colores de acolchado: blanco, plata, negro y como testigo el suelo sin acolchar en un diseño de bloques con arreglo en franjas. El trabajo se desarrolló en la pequeña propiedad Esmeralda en el municipio de Gómez Palacio, Durango. En el ciclo primavera-verano de 2012. Las variables evaluadas fueron: altura de planta, diámetro de tallo, diámetro y longitud de elote, peso fresco y seco de planta e índice de área foliar (IAF). Los resultados obtenidos muestran que no hubo diferencia significativa (p≤ 0.05) entre los colores de acolchado para la producción de materia seca, pero si hubo diferencia con respecto al suelo sin acolchar. Se obtuvo un modelo de crecimiento del IAF en función de los días después de siembra tipo cuadrático Yca= -0.002X2 + 0.294X -5.8183, R2= 0.97 para acolchado y Ysa= -0.0017X2 + 0.259X -5.503, R2= 0.94 sin acolchar y un modelo de producción de materia seca en función del IAF de tipo lineal Yca= 86.295X -110.84, R2= 0.92 y Ysa= 65.761X -55.764, R2= 0.91 ambos para el sistema con y sin acolchado. Se concluye que la utilización de acolchados plásticos para la producción de maíz forrajero incremento los rendimientos hasta 25% más con respecto al sistema sin acolchar.

The objectives of this study were to identify and rank the covariables of soil-forming factors that affect the distribution and spatial variability of pH in an agricultural area and to obtain a predictive map of soil pH. Samples of topsoil were obtained from different sites and taken to the laboratory, where they were prepared to determine the pH, organic matter, and percentages of particle size. In addition, the values of environmental covariables that affect pH were obtained. A database of the coordinates, laboratory results, and values of the covariables was constructed. Principal component analysis of the covariables was performed, and an analysis of the pH spatial structure was conducted and interpolated to obtain a predictive map of pH. Of the soil physical characteristics, the covariables clay and sand had a greater influence on the spatial behavior of pH with respect to the rest of the covariables of soil-forming factors, while human activity acted as a catalyst of the acidification process. Soil pH exhibited autocorrelation and moderate spatial dependence (66.7%) and was thus spatially predictable. The pH prediction map was accurate (RMSE = 0.158 and MEB = 0.020).