The excessive use of fertilizers in agriculture is mainly due to the recognized plant requirements for soluble phosphorus. This problem has limited the implementation of sustainable agriculture. A viable alternative is to use phosphate solubilizing soil microorganisms. This work aimed to isolate inorganic phosphorus-solubilizing bacteria from the soils of agroecosystems, to select and identify, based on sequencing and phylogenetic analysis of the 16S rRNA gene, the bacterium with the highest capacity for in vitro solubilization of inorganic phosphate. Additionally, we aimed to determine its primary phosphate solubilizing mechanisms and to evaluate its effect on Habanero pepper seedlings growth. A total of 21 bacterial strains were isolated by their activity on Pikovskaya agar. Of these, strain ITCB-09 exhibited the highest ability to solubilize inorganic phosphate (865.98 µg/mL) through the production of organic acids. This strain produced extracellular polymeric substances and siderophores that have ecological implications for phosphate solubilization. 16S rRNA gene sequence analysis revealed that strain ITCB-09 belongs to the genus Enterobacter. Enterobacter sp. ITCB-09, especially when immobilized in beads, had a positive effect on Capsicum chinense Jacq. seedling growth, indicating its potential as a biofertilizer.

Se describe y compara la estructura y composición de la selva baja caducifolia (SBC) y la selva medianasubcaducifolia (SMS) en 2 localidades en Campeche, México. Se comparó la riqueza de especies, abundancia ydistribución de los árboles, así como sus características dasométricas dentro de cada comunidad vegetal; establecimos27 parcelas de 500 m2 y se contaron todos los individuos ≥ 3 cm de diámetro a la altura del pecho. Se registraron 3162 individuos, pertenecientes a 83 especies y 30 familias. La riqueza de especies de árboles fue mayor en el SMS;70 especies en 30 familias, 13 especies promedio por parcela; que en SBC fueron 50 especies en 21 familias y seregistraron 11 especies por parcela. La diversidad de árboles en la SBC fue de 1.91 (±0.34) frente a 2.10 (±0.32)en la SMS. En consecuencia, las comunidades no se distribuyen uniformemente, tanto en SMS (J= 0.65 ± 0.12) ySBC (J= 0.63±0.12).

Se comparó el efecto del uso de suelo sobre la mirmecofauna del ejido de Tikinmul, Campeche, México. El estudio se llevó a cabo en monocultivos de cedro y huertos caseros, durante la época seca y lluviosa. Para la colecta de especies se utilizó el método Tropical Soil Biology and Fertility (TSBF) modificado para sistemas agroforestales. Se encontraron un total de 37 morfoespecies, de las cuales nueve son exclusivas de cada uno de los dos sistemas, mientras 19 están presentes en ambos. Se observa una similitud (Sörensen) de 60.4% entre sistemas y 68% entre épocas. La subfamilia Myrmicinae con 8 géneros y 17 especies fue la mejor representada en el estudio. Solenopsis geminata y Dorymyrmex sp.fueron especies dominantes e indicadoras del monocultivo. La densidad de hormigas fue más alta en los monocultivos. No se encontró relación directa de la intensidad de manejo con la riqueza de especies. La cantidad de hojarasca se muestra como el factor determinante de abundancia de las hormigas. Los agroquímicos afectan de manera indirecta a sus poblaciones.

Background: The use of Tithonia diversifolia foliage can improve the quality of animal feed because its crude protein content doubles that of tropical grasses. However, plant response regarding biomass production to frequent harvest disturbances are not known well. Objective: To evaluate the effect of different cutting heights and repeated harvests on biomass production and nutrient content of T. diversifolia in fodder banks under warm sub-humid climate. Methodology: We used a completely randomized design with a factorial arrangement; the treatments consisted of six harvest dates: Mar, May, July, September, November 2019 and January 2020; and three harvest heights: 40, 60 and 80 cm from the ground level. After each harvest date, the biomass was separated into different components, weighed and dried. Samples were taken to analyse the chemical composition of the forage. Results: The highest yield of leaves was found in the month of January, while tender stems in November. The Senescent material and total biomass were lower in September. The cutting height influenced leaf yield. Crude protein content was higher in September at a cutting height of 60 cm. Neutral detergent fiber was higher in the month of November for all cutting heights. Likewise, the highest contents of acid detergent fiber were in November for all cutting heights and in January for the cutting height of 60 cm. Lignin content was similar for all treatments. Implications: These results contribute to the development sustainable livestock production by providing alternatives to reduce grassland degradation from overgrazing. Conclusion: Biomass yield and chemical composition of T. diversifolia are affected by harvest date and heights, so it is necessary to consider it in the management strategies for optimal use of forage resources, incorporation in silvopastoral systems and the development of sustainable livestock production.