Summary: The soil seed bank is key to plant succession. However, agricultural activities have had a great impact on the vegetation and its composition. The aim was to determine the soil seed bank in different grazing agroecosystems in the central part of Veracruz state, Mexico. Richness, abundance, diversity, equity, dominance and similarity of the species were quantified and compared among four agroecosystems (silvopastoral, pasture-trees, traditional grazing, and Acahual or secondary vegetation) in Veracruz, Mexico during the year 2017. Samples were collected. of soil at two depths (0-5, > 5-10 cm). A statistical difference was found in the seed bank (P < 0.05) in silvopastoral at both depths, 0-5 (H’ = 2.13) and 5-10 (H’ = 1.86). Equity and dominance were higher for this agroecosystem (0.86) and for Acahual (0.58) with statistical differences (P < 0.05). No statistical differences were found at sites between depths (P > 0.05). Similarity was greater than 50% at all sites and increased with soil depth. The evidence suggests that the greatest diversity of the seed bank was in silvopastoral from 0 to 5 cm deep. The seed bank has potential for the restoration of vegetation, mainly herbaceous, and can promote the development of shrubs and trees, despite the management of cattle ranching sites.

Resumen: El banco de semillas del suelo es clave para la sucesión vegetal. Sin embargo, las actividades agrícolas han tenido un gran impacto en la vegetación y su composición. El objetivo fue determinar el banco de semillas del suelo en diferentes agroecosistemas de pastoreo en la parte central del estado de Veracruz, México. Se cuantificó y comparó la riqueza, abundancia, diversidad, equidad, dominancia y similitud de las especies entre cuatro agroecosistemas (silvopastoril, pastos-árboles, pastoreo tradicional, y Acahual o vegetación secundaria) en Veracruz, México durante el año 2017. Se recolectaron muestras de suelo a dos profundidades (0-5, > 5-10 cm). Se encontró diferencia estadística del banco de semillas (P < 0.05) en silvopastoril en ambas profundidades, 0-5 (H’= 2.13) y 5-10 (H´ = 1.86). La equidad y la dominancia fueron mayores para este agroecosistema (0.86) y para Acahual (0.58) con diferencias estadísticas (P < 0.05). No se encontraron diferencias estadísticas en sitios entre profundidades (P > 0.05). La similitud fue mayor al 50% en todos los sitios y aumentó con la profundidad del suelo. La evidencia sugiere que la mayor diversidad del banco de semillas estuvo en silvopastoril de 0 a 5 cm de profundidad. El banco de semillas tiene potencial para la restauración de la vegetación, principalmente herbácea y puede promover el desarrollo de arbustos y árboles, a pesar del manejo de sitios para la ganadería.

Abstract The use of chemical inputs has led to the loss of microbial diversity involved in the N cycle, such as diazotrophic bacteria, which are inhibited by saturation of the receptors responsible for activating nitrogenase. Biological nitrogen fixation (BNF) in forage grasses can be used as an ecosystem service. The aim of this review was to analyze the contribution of forage grasses to BNF and their response to inoculation of non-symbiotic diazotrophs in order to find study opportunities. The analysis of the information was carried out using the prisma methodology of systematic reviews and meta-analyses. It should be noted that the main forage species that contribute to BNF are Brachiaria sp. and Pennisetum sp. The inoculation of Azospirillum sp. has generated a growth-promoting effect in grasses, but the response of the inoculated forage depends mainly on the synergy between plant and bacteria, showing neutral, antagonistic, and positive effects.

Resumen El uso de insumos de origen químico ha generado pérdida de la diversidad microbiana que interviene en el ciclo del N como bacterias diazótrofas, que son inhibidas por saturación de los receptores encargados de activar la nitrogenasa. La fijación biológica de nitrógeno (FBN) en gramíneas forrajeras puede ser utilizada como servicio ecosistémico. El objetivo de este artículo de revisión fue analizar la contribución de gramíneas forrajeras a la FBN y su respuesta a la inoculación de diazótrofas no simbióticas para encontrar oportunidades de estudio. El análisis de la información se realizó a partir de la metodología prisma de revisiones sistemáticas y meta-análisis. Se destaca que las principales especies forrajeras que contribuyen con la FBN corresponden a Brachiaria sp. y Pennisetum sp. La inoculación de Azospirillum sp. ha generado efecto promotor de crecimiento en gramíneas, pero, la respuesta del forraje inoculado depende principalmente de la sinergia entre planta - bacteria presentándose efectos neutros, antagónicos y positivos.

Abstract In order to establish the incidence and distribution of termite populations on native grassland (Paspalum notatum L.) production, cattle farms and their surroundings were examined in Itacurubi del Rosario, department of San Pedro, Paraguay; using the GPS nest location method (Garmin Map 76 CSx), drones, capture of aerial photographs and then the evaluation of the incidence and distribution of termite nests per hectare. Maps of incidence and distribution of nests were made for a surface of seven hectares. From the data generated, a map with the distribution of active termite nests was prepared using the QGIS software version 3.18. The formation of termite mounds represented an average area of 12 m² and an intensity of 13.5% per hectare, distributed in an average of 96.2 nests per hectare, totaling some 8,085 termite nests within the study area for a total area of 7 ha. Examples of species were represented by the family: Termitidae (Cornitermes cumulans, Nasutitermes nigriceps and Termes sp.) of wide distribution in the study area. The presence of termite mounds negatively affects the useful productive area due to the occupied area and a significant loss of pasture per day to feed the animals in each season of the year.

Resumen Con el fin de evaluar la incidencia y distribución de las poblaciones de termitas sobre la producción del pastizal nativo (Paspalum notatumL.), se muestrearon fincas ganaderas y su entorno en Itacurubi del Rosario - Departamento de San Pedro - Paraguay. Los termiteros fueron localizados utilizando un GPS de la marca Garmin Map 76 CSx y drones equipados con cámaras fotográficas para las capturas de fotografías aéreas. Se realizaron mapas de incidencia y distribución de termiteros para la superficie de uno y 7,4 hectáreas. A partir de los datos generados, se elaboró un mapa con la distribución de los termiteros activos mediante el software QGIS versión 3.18. La formación de los termiteros representó una superficie promedio de 12 m² en promedio y una intensidad de 13,5% por hectárea, distribuidos en un promedio de 96,2 nidos por hectárea, totalizando unos 711,88 termiteros dentro del área de estudio para una superficie total de 7,4 ha. La familia Termitidae estuvo representadas por las siguientes especies: (Cornitermes cumulans,Nasutitermes nigricepsyTermessp.) de amplia distribución en el área de estudio. La cantidad de termiteros encontrados afecta la superficie útil productiva del pastizal, así como a la disponibilidad de pastos para la alimentación animal en las distintas épocas del año.

Resumen: La investigación tuvo como objetivo analizar el manejo de praderas nativas como una estrategia de adaptación al cambio climático en el altiplano central, municipio de Patacamaya, Bolivia. Para ello, se analizó el manejo del ganado tradicional en períodos de alta vulnerabilidad, observando la relación entre el estrés hídrico y el uso de especies forrajeras. La investigación fue descriptiva y relacional con 6 especies, 3 comunidades (Alto Patacamaya, Chiaraque y Patarani), y un total de 216 muestras tomadas entre julio 2015 y noviembre 2016. Se midieron el contenido gravimétrico de agua del suelo y el potencial hídrico al alba de la hoja, y se aplicó una caracterización fitoecológica. Los resultados obtenidos indican que el manejo estratégico tradicional temporal muestra una relación entre el tipo de manejo de las áreas de pastoreo y el tipo de forraje consumido. Como estrategia, los productores arrean su ganado a zonas cubiertas por forraje nativo o a zonas donde es posible adquirir forraje en ferias cercanas. Las especies más pastoreada en invierno fueron Festuca orthophylla y Stipa ichu con potenciales hídricos de -3,5 MPa y -4,1 MPa, respectivamente, en Chiaraque.

Abstract: The research aimed to analyze the management of native prairies as an adaptation strategy to climate change in the central highlands, Patacamaya district, Bolivia. For this, traditional livestock management was analyzed in periods of high vulnerability, observing the relationship between water stress and the use of forage grass species. The study was descriptive and relational, with 6 grass species, 3 communities (Alto Patacamaya, Chiaraque, and Patarani), and a total of 216 samples taken between July 2015 and November 2016. Gravimetric soil water content and leaf water potential at dawn were measured, and a phyto-ecological characterization was carried out. The results obtained indicate that traditional strategic management shows a relationship between the type of prairie management and the type of forage consumed. As a strategy, farmers lead their livestock to land areas covered with native grass species or areas where forage can be purchased locally. Festuca orthophylla and Stipa ichu were the most widely consumed grass species in winter, reaching water potential values of -3.5 and -4.1 MPa, respectively, in Chiaraque.

ABSTRACT Understanding the dietary needs is important for the conservation of the bighorn sheep. The objective was to identify the diet selection in Coahuila, Mexico. The research was conducted at the Rancho San Juan Wildlife Management Unit (UMA), Monclova municipality, from August 2018 to October 2019. Forage availability was assessed using 18 Canfield transects. Diet composition was estimated through microhistology on 280 fecal samples, and diet and forage diversity were assessed using the Shannon index. Cluster and principal component analyses (PCA) were applied to analyze similarity in consumption across different species and seasonal influences. Shrubs were the most available (48%). A total of 50 species and 14 families were identified in the diet, with shrubs (49.2%) and grasses (17.21%) being predominant. Tiquilia canescens, Gymnosperma glutinosum, Opuntia rufida, Medicago sativa, and Erioneuron pulchellum were the most consumed species. The bighorn sheep consumed tree and shrub species proportionally (1.1 and 1.02, respectively), preferred herbaceous plants in spring (2.24) and autumn (15.28), and grasses in spring (6.10), except in summer (0.83) when they avoided succulents. PCA revealed that the first two components explained 96.05% of the correlation between species consumption frequencies and their biological forms. Cluster analysis grouped five forage consumption categories. Conserving shrub species, which form the basis of the bighorn sheep's diet, grasses-its preference-and succulents as buffering elements, is essential.

RESUMEN Comprender las preferencias alimentarias es importante para la conservación del borrego cimarrón. El objetivo fue identificar la selección de su dieta en Coahuila, México. La investigación se realizó en la UMA Rancho San Juan, municipio de Monclova, de agosto 2018 a octubre 2019. La disponibilidad de forraje se evaluó con 18 líneas de Canfield. La composición de la dieta se estimó con microhistología en 280 muestras fecales, y la diversidad de la dieta y del forraje con el índice de Shannon. Para analizar la similitud en el consumo de diferentes especies y la influencia estacional, se aplicaron análisis de clústers y componentes principales (ACP). Las arbustivas estuvieron más disponibles (48%). Se identificaron 50 especies y 14 familias en la dieta, y predominaron las arbustivas (49.2%) y los pastos (17.21%). Tiquilia canescens, Gymnosperma glutinosum, Opuntia rufida, Medicago sativa y Erioneuron pulchellum fueron las más consumidas. El borrego consumió especies arbóreas y arbustivas de manera proporcional (1.1 y 1.02, respectivamente), prefirió las herbáceas en primavera (2.24) y otoño (15.28), los pastos en primavera (6.10), y con excepción de verano (0.83), evitó las suculentas. El ACP reveló que los dos primeros componentes explican el 96.05% de la correlación entre las frecuencias de consumo de las especies y sus formas biológicas. El análisis de clústers agrupó cinco categorías de consumo de forraje. Es fundamental conservar las arbustivas, que constituyen la base de la dieta del borrego cimarrón, los pastos, que son sus preferidos, y las suculentas, como elementos amortiguadores.

Resumen Antecedentes: El reto actual consiste en producir alimentos en sistemas resilientes al cambio climático y cuidar el medio ambiente. Objetivo: Evaluar la biofertilización orgánica y mineral en el crecimiento y desarrollo de posturas de Tithonia diversifolia durante la fase de vivero. Materiales y métodos: Se llevaron a cabo dos ensayos: E-I en la CPA “Renato Guitar” y E-II: en la Estación Experimental de Pastos y Forrajes Indio Hatuey (EEPFIH). Para el desarrollo de los mismos se empleó un diseño experimental totalmente aleatorizado con 15 y 10 réplicas, experimento I y II respectivamente. E-I se llevaron a cabo tres tratamientos: T-1: suelo 100% sin abonar, T-2: suelo 50% + biochar 50%, T-3: suelo 50%+ biochar 25% + ceniza de bagazo de caña 25%. El biochar se obtuvo de marabú (D. cinerea) y siempre fue embebido en microorganismos eficientes IHPLUS®BF. Se midieron parámetros fisiológicos del metabolismo primario y secundario a los 30 días, e indicadores morfológicos de crecimiento a los 30 y 60 días. En el E-II se trabajó con 5 tratamientos: T-1: Suelo sin abonar, T-2: Combinación de 50%suelo-50%compost + Rhizobium, T-3: Combinación de 50%suelo-50%compost + Trichoderma, T-4: Combinación de 50%suelo-50%compost con dolomita micronizada + Rhizobium y T-5: Combinación de 50%suelo-50%compost con dolomita micronizada + Trichoderma. Se midieron indicadores morfológicos de crecimiento a los 60 días y producción de biomasa aérea seca en el momento del trasplante. Resultados: los resultados arrojan que en el Ensayo- I la mejor variante fue T-3: suelo 50%+Biochar enriquecido IHPLUS®BF 25%+cenizas 25%. Ensayo- II, todas las variantes estudiadas fueron superior que el testigo. Conclusión: Los resultados permitieron confirmar la efectividad de dichas alternativas para cultivar plantas de T. diversifolia en condiciones de vivero.

Abstract Background: The current challenge is to produce food in systems that are resilient to climate change and take care of the environment. Aim. Evaluate organic and mineral biofertilization in the growth and development of Tithonia diversifolia positions during the nursery phase. Materials and methods: Two trials were carried out: E-I at the “Renato Guitar” CPA and E-II: at the Indio Hatuey Pasture and Forage Experimental Station (EEPFIH). For their development, a completely randomized experimental design was used with 15 and 10 replications, experiment I and II respectively. E-I, three treatments were carried out: T-1: 100% unfertilized soil, T-2: 50% soil + 50% biochar, T-3: 50% soil + 25% biochar + 25% cane bagasse ash. The biochar was obtained from marabou (D. cinerea) and was always embedded in efficient IHPLUS®BF microorganisms. Physiological parameters of primary and secondary metabolism were measured at 30 days, and morphological growth indicators at 30 and 60 days. In E-II, 5 treatments were used: T-1: Unfertilized soil, T-2: Combination of 50% soil-50% compost + Rhizobium, T-3: Combination of 50% soil-50% compost + Trichoderma, T-4: Combination of 50% soil-50% compost with micronized dolomite + Rhizobium and T-5: Combination of 50% soil-50% compost with micronized dolomite + Trichoderma. Morphological growth indicators were measured at 60 days and production of dry aerial biomass at the time of transplant. Results: the results show that in Trial-I the best variant was T-3: soil 50%+IHPLUS®BF enriched Biochar 25%+ash 25%. Test-II, all the variants studied were superior to the control. Conclusion: The results confirmed the effectiveness of these alternatives to grow T. diversifolia plants under nursery conditions.

Resumen Antecedentes: La producción de leche vacuna en Ecuador se diferencia por regiones; en la Costa y de forma particular la cuenca baja del Guayas, tiende a decrecer, determinado por factores socioeconómicos y ecológicos, sin embargo, constituye una prioridad para el consumo familiar y local, con demanda del producto y sus derivados, representa ingresos diarios, asegura el pago de jornales al productor y genera diversificación en los sistemas de producción. Objetivo: Valorar la producción de leche en Ecuador y su proyección a partir de escenarios con énfasis en la cuenca baja del Guayas. Desarrollo: Se realizó una revisión bibliográfica para examinar la evidencia disponible sobre la producción de leche vacuna en Ecuador. Se constató un crecimiento, no obstante, la heterogeneidad de condiciones socioeconómicas y ecológicas existentes, determinaron respuestas productivas diferentes. Respecto a la cuenca baja del Guayas, reportaron los rendimientos más bajos, condicionados por factores climáticos y las características de los sistemas de producción, que determinan la búsqueda de alternativas que garanticen su sostenibilidad. Conclusiones: La producción de leche se diferenció por regiones, los mayores rendimientos se encontraron en la Sierra, seguido por la Amazonía y por último en la Costa, donde prevalecen los pastos naturales, existen desbalances estacionales y se prioriza la actividad agrícola. En correspondencia con lo planteado, la construcción de escenarios prospectivos constituye una alternativa para la toma de decisión en la relación a la sostenibilidad de la producción de leche en la región.

Abstract Background: The production of bovine milk in Ecuador differs by region; On the coast and particularly the lower Guayas basin, it tends to decrease, determined by socioeconomic and ecological factors, however, it constitutes a priority for family and local consumption, with demand for the product and its derivatives, it represents daily income, he assures. the payment of wages to the producer and generates diversification in production systems. Aim. Assess milk production in Ecuador and its projection based on scenarios with emphasis on the lower Guayas basin. Development: A bibliographic review was carried out to examine the available evidence on bovine milk production in Ecuador. Growth was noted, however, the heterogeneity of existing socioeconomic and ecological conditions will determine different productive responses. Regarding the lower Guayas basin, they reported the lowest yields, conditioned by climatic factors and the characteristics of the production systems, which determine the search for alternatives that guarantee their sustainability. Conclusions: Milk production differs by region, the highest yields were found in the Sierra, followed by the Amazon and finally on the Coast, where natural pastures prevail, there are seasonal imbalances and agricultural activity is prioritized. In correspondence with what was stated, the construction of prospective scenarios constitutes an alternative for decision-making in relation to the sustainability of milk production in the region.

Abstract Pastures that include annual and perennial grasses can play a strategic role in increasing the sustainability of temperate livestock systems. However, the impacts of the competition between annual and perennial genetically improved forage species on pastures has scarcely been studied. We evaluated the early dynamics of tillering, carbon partitioning and both intra- and interspecific competition in – or between – an annual (Bromus willdenowii; prairie grass; Bw) and a perennial (Dactylis glomerata; orchard grass; Dg) C3 grass species. We sowed 24 0.18 m2 microplots in May 2008. Each microplot constituted an experimental unit and contained five sowing lines spaced 0.175 m apart. On three of the lines, we sowed different combinations of the mentioned grasses, while on the two lines between them, we sowed red clover (Trifolium pratense). We randomly applied a factorial array of eight treatments—2 species (Dg vs. Bw) × 2 types of competition (intra vs. interspecific) × 2 levels of winter nitrogen fertilization (0 vs. 170 kg of N ha-1)—designed in three complete random blocks. Fertilization did not have any significant effect on any species. The evaluation period lasted 109 days after sowing (das), separated into three phases (0-53 das, 59-90 das and 90-109 das). The variables recorded were aerial biomass (leaves, sheets and senescent material), root biomass and tiller density per species. As expected, annual Bw inhibited the growth of perennial Dg at the latest stage of establishment but surprisingly promoted it at the earliest stage. This work suggested that a low initial density of an annual species should optimize the initial facilitating effect of the annual species on the perennial species with its subsequent inhibitory effect.

Resumen Las gramíneas anuales y perennes pueden desempeñar un papel estratégico en el aumento de la sostenibilidad de los sistemas ganaderos de zonas templadas. Sin embargo, el impacto de la competencia entre especies forrajeras genéticamente mejoradas anuales y perennes en los pastos apenas ha sido estudiado. En este trabajo evaluamos la dinámica temprana del macollaje y la partición de carbono y la competencia intraespecífica e interespecífica en, o entre, una especie de pasto C3 anual (Bromus willdenowii; pasto de la pradera; Bw) y perenne (Dactylis glomerata; pasto de huerto; Dg). Sembramos 24 microparcelas de 0,18 m2 en mayo de 2008. Cada microparcela constituyó una unidad experimental y contenía cinco líneas de siembra espaciadas 0,175 m entre sí. En tres de las líneas sembramos diferentes combinaciones de las gramíneas mencionadas, mientras que en las dos líneas intermedias sembramos trébol rojo (Trifolium pratense). Aplicamos aleatoriamente un conjunto factorial de ocho tratamientos: 2 especies (Dg vs. Bw) × 2 tipos de competencia (intra vs. interespecífica) × 2 niveles de fertilización con nitrógeno invernal (0 vs. 170 kg de N ha-1), diseñado en tres bloques completos al azar. La fertilización no tuvo ningún efecto significativo en ninguna especie. El período de evaluación tuvo una duración de 109 días después de la siembra (dds), separados en tres fases (0-53 dds, 59-90 dds y 90-109 dds). Las variables registradas fueron biomasa aérea (hojas, láminas y material senescente), biomasa de raíces y densidad de macollos por especie. Como se esperaba, Bw inhibió el crecimiento de Dg en la última etapa de establecimiento, pero sorprendentemente lo promovió en la etapa más temprana. Este trabajo sugirió que una baja densidad inicial de una especie anual debería optimizar el efecto facilitador inicial de la especie anual sobre la especie perenne con su posterior efecto inhibidor.

Abstract The estimation of aerial biomass of grasses contributes to carrying out efficient and sustainable management of rangelands. This study aimed to generate new equations to estimate the aerial biomass of grasses present in rangelands in Nuevo León, Mexico, based on data collected from the total number (n= 745) of individuals of the five species of grasses: Cenchrus ciliaris Linnaeus, Pappophorum bicolor Fourn, Aristida purpurea Nutt, Tridens texanus Watson and Paspalum pubiflorum Fourn present in the sampling plots. Using the maximum height and the height of the vegetative stems, the aerial, basal, and compressed diameters, and volumes measured in each of the collected individuals, linear (stepwise) and nonlinear equations were generated to estimate the aerial biomass (dry matter basis) of the grasses cut at ground level. Six general equations with the best statistical fit for the total species collected were selected. General equation III had the best values of R2 =0.88 and AIC =3079, using the five variables evaluated. General equation IV had an R2 =0.86 and AIC =3530, using only the variable compressed diameter. The selected specific equations estimated the aerial biomass of the grasses Cenchrus ciliaris (R2=0.88, r=0.94), Pappophorum bicolor (R2 =0.86, r =0.92), Aristida purpurea (R2=0.92, r=0.96), Tridens texanus (R2 =0.91, r =0.96), and Paspalum pubiflorum (R2 =0.93, r = 0.97). The new equations are a reliable alternative to indirectly estimate the aerial biomass of the grasses of the rangelands of northeastern Mexico in a faster and less expensive manner than the traditional method.

Resumen La estimación de biomasa aérea de pastos contribuye a realizar un manejo eficiente y sostenible de los agostaderos. El objetivo del presente estudio fue generar nuevas ecuaciones para estimar la biomasa aérea de pastos presentes en agostaderos, en Nuevo León, México, basado en datos colectados del total (n=745) de los individuos de las cinco especies de pastos: Cenchrus ciliaris Linnaeus, Pappophorum bicolor Fourn, Aristida purpurea Nutt, Tridens texanus Watson y Paspalum pubiflorum Fourn presentes en las parcelas de muestreo. Utilizando la altura máxima y la de los tallos vegetativos, los diámetros aéreo, basal y comprimido, y volúmenes medidos en cada uno de los individuos colectados, se generaron ecuaciones lineales (stepwise) y no lineales, para estimar la biomasa aérea (base materia seca) de los pastos cortados a ras de suelo. Se seleccionaron seis ecuaciones generales con el mejor ajuste estadístico para el total de las especies colectadas. La ecuación general III tuvo los mejores valores de R2=0.88 y AIC=3079, utilizando las cinco variables evaluadas. La ecuación general IV estimó con R2=0.86 y AIC= 3530, utilizando solo la variable de diámetro comprimido. Las ecuaciones específicas seleccionadas estimaron la biomasa aérea de los pastos Cenchrus ciliaris (R2=0.88, r=0.94), Pappophorum bicolor (R2=0.86, r=0.92), Aristida purpurea (R2=0.92, r=0.96), Tridens texanus (R2=0.91, r=0.96), y Paspalum pubiflorum (R2=0.93, r=0.97). Las nuevas ecuaciones son una alternativa confiable para estimar indirectamente la biomasa aérea de los pastos de los agostaderos del noreste de México, de forma más rápida y menos costosa que el método tradicional.

Abstract This study aimed to evaluate whether bacterial inoculation improves the fermentative, microbiological, and chemical characteristics of silages of the elephant grass cv. BRS Capiaçu on different regrowth days. The experimental design was completely randomized and set up in a 3x2 factorial arrangement (three regrowth days, with and without inoculant), with four replications. There was a significant interaction between the regrowth days and inoculant on the pH, ammoniacal nitrogen (N-NH3), and effluent losses (EL) of the silages. Inoculation decreased the EL with the advance of regrowth days and increased the dry matter recovery index compared to the silages without inoculant. The population of molds and yeasts decreased when inoculation was adopted to the forage harvested after 85 d. There was a significant interaction between the dry matter (DM), crude protein (CP) and neutral detergent fiber corrected for ash and protein (NDFap) contents of the silages. Inoculation in the grass harvested after 85 d increased the DM contents of the silage. The highest CP contents were observed in the silages after 85 d. The NDFap contents of the grasses harvested after 110 and 135 d were higher than those of the grass harvested after 85 d. The NDFap contents of the silages without inoculant increased with the harvest age. The BRS Capiaçu forage silage harvested at 110 d demonstrated favorable performance for silage production. However, the influence of inoculant use was low for the characteristics evaluated.

Resumen Este estudio tuvo como objetivo evaluar si la inoculación bacteriana mejora las características fermentativas, microbiológicas y químicas de los ensilados del pasto elefante cv. BRS Capiaçu en diferentes días de rebrote. El diseño experimental fue completamente al azar y se estableció en un arreglo factorial 3x2 (tres días de rebrote, con y sin inoculante), con cuatro repeticiones. Hubo una interacción significativa entre los días de rebrote y el inoculante sobre el pH, el nitrógeno amoniacal (N-NH3) y las pérdidas por efluentes (PE) de los ensilados. La inoculación disminuyó la PE con el avance de los días de rebrote y aumentó la tasa de recuperación de materia seca en comparación con los ensilados sin inoculante. La población de mohos y levaduras disminuyó cuando se adoptó la inoculación al forraje cosechado después de 85 d. Hubo una interacción significativa entre la materia seca (MS), la proteína cruda (PC) y la fibra detergente neutro corregida por los contenidos de cenizas y proteína (FDNcp) de los ensilados. La inoculación en el pasto cosechado después de 85 días aumentó el contenido de MS del ensilado. Los mayores contenidos de PC se observaron en los ensilados después de 85 días. Los contenidos de FDNcp de los pastos cosechados después de 110 y 135 días fueron mayores que el del pasto cosechado después de 85 días. El contenido de FDNcp de los ensilados sin inoculante aumentó con la edad de cosecha. El ensilado de forraje de BRS Capiaçu cosechado a los 110 días demostró un desempeño favorable para la producción de ensilado. Sin embargo, la influencia del uso de inoculantes fue baja para las características evaluadas.

Abstract Background: Roadside plants grow along transportation routes, and are little studied. Questions: What is the richness of roadside angiosperms? What is the percentage of native and introduced species for roadside angiosperms? Species studied: Native and introduced roadside angiosperms. Site and years of study: Chalma-Malinalco roadside, municipality of Malinalco, State of Mexico, Mexico, May 2008-April 2009. Methods: Angiosperm species were collected along the road right-of-way during 24 biweekly walks. Additionally, species were listed and their cover estimated in 14 sampling sites (4 m2 each). Results: We recorded 327 species. Asteraceae, Fabaceae and Poaceae were the families with the highest richness of genera and species. Native species were dominant (85.9 %), whereas introduced species grouped 14.1 %; the latter came mainly from the Old World. About 70 % of the species were herbs. Bouteloua repens and Eleusine indica had the highest cover and frequency, respectively. Conclusions: The roadside flora was rich in angiosperms, mostly herbs, and with a dominance of native plants. Introduced grasses played an outstanding role in terms of frequency. It is necessary to continue with floristic, ecological and ethnobotanical research, among others, on this group of plants that has been scarcely studied.

Resumen Antecedentes: Las plantas viarias crecen en las orillas de vías de comunicación y han sido poco estudiadas. Preguntas: ¿Cuál es la riqueza de las angiospermas viarias? ¿Cuál es el porcentaje de especies nativas e introducidas entre las angiospermas viarias? Especies de estudio: Angiospermas viarias nativas e introducidas. Sitio y años de estudio: Carretera Chalma-Malinalco, municipio de Malinalco, Estado de México, México, mayo 2008-abril 2009. Métodos: Se recolectaron las especies de angiospermas en el derecho de vía de la carretera a través de 24 recorridos quincenales. Adicionalmente, se enlistaron las especies y se estimó su cobertura en 14 cuadros de muestreo (4 m2 cada uno). Resultados: Se registraron 327 especies. Asteraceae, Fabaceae y Poaceae fueron las familias con mayor riqueza de géneros y especies. Las especies nativas fueron dominantes (85.9 %), mientras que las introducidas agruparon el 14.1 %; éstas últimas procedieron principalmente del Viejo Mundo. Alrededor del 70 % de las especies fueron hierbas. Bouteloua repens y Eleusine indica presentaron mayor cobertura y frecuencia, respectivamente. Conclusiones: La flora viaria era rica en angiospermas, la mayoría hierbas y con dominancia de plantas nativas. Los pastos introducidos tenían un papel sobresaliente en cuanto a frecuencia. Es necesario continuar con investigaciones florísticas, ecológicas, etnobotánicas, entre otras, sobre este grupo de plantas que ha sido escasamente estudiado.

ABSTRACT: In integrated crop-livestock systems, overseeding annual summer pastures over grain crops can reduce forage shortages in autumn without altering grain production. This study evaluated the influence of pearl millet (Pennisetumglaucum L.) and sudangrass (Sorghum Sudanese) overseeded on a soybean (Glycine Max) crop or no-tillage seeding after soybean harvest on productive aspects of pasture. The experimental design was a randomized block with treatments in a 2 × 2 factorial arrangement (pearl millet or sudangrass, overseeding in the full seed stage (R6) of soybean crops or seeding them in a no-tillage system after soybean harvest) in two agricultural years. Pasture height, plant stand, tiller density, and forage production were higher in the first crop year. The overseeding strategy resulted in higher pasture height and foraged production in the first crop year and higher pasture utilization for the next two crop years. Under the no-tillage strategy, the plants stand more elevated in the first crop year, resulting in a higher tiller density in the second crop year. Pasture height, utilization period, and forage production did not differ among the forage species. Pearl millet had a more elevated plant stand, while sudangrass had a higher tiller density. Annual summer pasture overseeding of soybean crops increases the pasture utilization period and forage production in autumn. ABSTRACT croplivestock livestock systems Pennisetumglaucum L. L Sorghum Sudanese Glycine Max notillage no tillage R6 R (R6 years species (R

RESUMO: Em sistemas integrados de produção agropecuária, a sobressemeadura de pastagens anuais de verão sobre as lavouras de grãos, pode reduzir a escassez de forragem no outono sem alterar a produção de grãos. Este trabalho avaliou a influência do milheto (Pennisetum glaucum L.) e do capim-sudão (Sorghum Sudanese) sobressemeados na lavoura de soja (Glycine Max) ou semeadura em plantio direto após a colheita da soja sobre os aspectos produtivos da pastagem. O delineamento experimental foi em blocos casualizados com tratamentos em arranjo fatorial 2 × 2 (milheto ou capim-sudão, semeadura no estádio (R6) da lavoura de soja ou semeadura em sistema de plantio direto após a colheita da soja) em dois anos. A altura do pasto, estande de plantas, densidade de perfilhos e produção de forragem foram maiores no primeiro ano agrícola. A estratégia de sobressemeadura resultou em maior altura de pastagem e produção de forragem na primeira safra e maior utilização da pastagem nas duas safras. Na estratégia de plantio direto, as plantas ficaram mais elevadas no primeiro ano e com maior densidade de perfilhos no segundo ano agrícola. A altura do pasto, o período de utilização e a produção de forragem não diferiram entre as espécies forrageiras. O milheto apresentou estande de plantas mais elevado, enquanto o capim-sudão apresentou maior densidade de perfilhos. A sobressemeadura anual das pastagens de verão na cultura da soja aumenta o período de utilização das pastagens e a produção de forragem no outono. RESUMO agropecuária grãos Pennisetum L. L capimsudão capim sudão Sorghum Sudanese Glycine Max capimsudão, sudão, R6 R (R6 anos pasto agrícola safras forrageiras elevado (R

ABSTRACT: In Brazil, urea is the most used nitrogen (N) fertilizer to improve forage production. However, their excessive use can cause environmental impacts through N losses, such as ammonia (NH3) volatilization. Therefore, the current study adjusted and estimated the NH3 volatilization from urea applied on tropical pastures in three rainfall conditions using mathematical models. Data were collected from Marandu grass (Brachiaria brizantha) fertilized with 50 kg N ha-1 during wet, intermediate, and dry conditions. Ammonia volatilization was measured in five semi-open chambers for 21 days. The linear, quadratic, exponential, Gompertz, Groot, and Richards models were tested for fitting and estimating the NH3 volatilization. The Gompertz, Groot, and Richards models generated predictions similar to the observed data, with a high determination coefficient, indicating a better fit of these equations to data, with precision and accuracy. However, the Groot model was selected due to the lowest root mean square error of prediction (0.29 % total N lost as NH3). The greatest N loss as NH3 volatilization occurred in the wet, followed by intermediate and dry conditions (20.2, 17.0, and 11.3 % total N lost as NH3, respectively). Therefore, nitrogen losses as NH3 volatilization after application of 50 kg N ha-1, as urea source, are altered according to the weather conditions, reaching 20% of N added in the wet rainfall period. The Groot model is recommended for fitting and estimating the NH3 volatilization from urea applied on Marandu grass pastures in the wet and dry rainfall conditions. ABSTRACT Brazil (N production However NH (NH3 Therefore Brachiaria brizantha 5 ha1 ha 1 ha- semiopen semi open 2 days linear quadratic exponential Gompertz data coefficient accuracy 0.29 029 0 29 (0.2 NH3. . NH3) 20.2, 202 20 (20.2 170 17 17.0 113 11 3 11. respectively. respectively respectively) ha1, 1, source period (NH 0.2 02 (0. 20.2 (20. 17. 0. (0 20. (20 ( (2

RESUMO: No Brasil, a ureia é o fertilizante nitrogenado mais utilizado para melhorar a produção de forragem. No entanto, seu uso excessivo pode causar impactos ambientais por meio de perdas de nitrogênio (N), como a volatilização da amônia (NH3). Portanto, o objetivo do presente estudo foi ajustar a volatilização de NH3 da ureia aplicada em pastos tropicais em três condições de chuva utilizando modelos matemáticos. Dados foram coletados de pastos de capim-marandu (Brachiaria brizantha) adubado com 50 kg N ha-1 em condições úmidas, intermediárias e secas. A volatilização da NH3 foi medida em cinco câmaras semiabertas durante 21 dias. Os modelos, linear, quadrático, exponencial, Gompertz, Groot e Richards foram testados para ajuste e estimativa da volatilização do NH3. Os modelos de Gompertz, Groot e Richards geraram predições semelhantes aos dados observados, com alto coeficiente de determinação, indicando um melhor ajuste dessas equações aos dados, com acurácia e precisão. No entanto, o modelo Groot foi selecionado devido ao menor erro quadrático médio das predições (0,29% de N total perdido como NH3). A maior volatilização de NH3 ocorreu em condições climáticas úmida, seguido por intermediária e seca (20,2; 17,0 e 11,3% de N total perdido como NH3, respectivamente). Portanto, as perdas de N como volatilização de NH3 após a aplicação de 50 kg N ha-1, como fonte de ureia, são alteradas de acordo com as condições climáticas, atingindo a 20% do N adicionado nas condições úmidas. O modelo Groot é recomendado para ajuste e estimativa da volatilização de NH3 da ureia aplicada em pastos de capim Marandu em condições úmidas e secas. RESUMO Brasil forragem entanto N, , (N) NH . (NH3) Portanto matemáticos capimmarandu marandu Brachiaria brizantha 5 ha1 ha 1 ha- secas 2 dias linear exponencial Gompertz observados determinação precisão 0,29% 029 0 29 (0,29 NH3) úmida 20,2 202 20 (20,2 170 17 17, 113 11 3 11,3 respectivamente. respectivamente respectivamente) ha1, 1, (N (NH3 0,29 02 (0,2 20, (20, 11, (NH 0,2 (0, (20 0, (0 (2 (

ABSTRACT: The objective was to evaluate the animal production and ingestive behavior of the steers fed different supplements during the growth phase in Aruana grass, and the influence of this supplementation on production performance in feedlot phase. The treatments consisted of three supplements during the growing phase: mineral salt (0.12 g/kg of body weight - BW), low intake energy-protein supplement (1.26 g/kg of BW), and medium intake (3.76 g/kg of BW). Forage canopy characteristics, animal production, and animal behavior on pasture were evaluated in a completely randomized design with three replicates (paddocks). The titanium dioxide marker was used to determine the intake and apparent digestibility during the pasture phase. The production performance in feedlot was evaluated in a completely randomized design with eight replicates (animals). Twenty-four Aberdeen Angus steers (15 ± 1.5 months old; 364.8 ± 21.7 kg BW) were used. At the end of the growth phase the animals were confined and fed a single diet. Dry matter, crude protein, and neutral detergent fiber (NDF) contents of forage and intake were not influenced by the treatments. The average daily gain was higher for the medium intake supplement in pasture phase. The apparent digestibility of NDF (P = and chewing rate were higher for the medium intake supplement. The average daily gain and fat thickness of carcasses were higher for the medium intake supplement in the feedlot phase. The supplements of medium intake increase animal productivity during the growing phase on pastures and cattle’s finishing performance in intensive production systems. ABSTRACT grass 0.12 012 0 12 (0.1 gkg g BW, BW , energyprotein energy protein 1.26 126 1 26 (1.2 3.76 376 3 76 (3.7 BW. . characteristics paddocks. paddocks (paddocks) animals. (animals) Twentyfour Twenty four 15 (1 5 1. old 3648 364 8 364. 217 21 7 21. diet matter (NDF P cattles cattle s systems 0.1 01 (0. 1.2 2 (1. 3.7 37 (3. (paddocks (animals ( 36 0. (0 3. (3

RESUMO: O objetivo deste trabalho foi avaliar a produção animal e o comportamento ingestivo de novilhos alimentados com diferentes suplementos durante a fase de crescimento em capim Aruana, e a influência desta suplementação sobre o desempenho produtivo durante a fase de terminação em confinamento. Os tratamentos consistiram de três suplementos durante a fase de crescimento: sal mineral (0,12 g/kg do peso corporal - PC), suplemento energético-proteico de baixo consumo (1,26 g/kg do PC) e suplemento energético-proteico de médio consumo (3,76 g/kg do PC). As características do dossel forrageiro, a produção animal e o comportamento ingestivo em pastos de capim Aruana foram avaliados utilizando um delineamento inteiramente ao acaso com três repetições (piquetes). O marcador externo dióxido de titânio foi utilizado para determinar o consumo e digestibilidade aparente dos nutrientes na fase de pastagem. O desempenho em confinamento foi avaliado utilizando-se um delineamento inteiramente ao acaso com oito repetições (animais). Vinte e quatro novilhos Aberdeen Angus (15 ± 1,5 meses de idade; 364,8 ± 21,7 kg de peso corporal médio inicial) foram utilizados. Ao final da fase de recria, os animais experimentais foram confinados e alimentados com uma dieta única. Os teores de matéria seca, proteína bruta e fibra de detergente neutro (FDN) da forragem, bem como o consumo destas frações não foram alterados pelos tratamentos. O ganho médio diário foi superior para o suplemento de ingestão média na fase de pastagem. A digestibilidade da FDN e a taxa de ruminação na fase pastagem foram mais elevadas para o suplemento de média ingestão. O ganho médio diário e a espessura de gordura das carcaças foram mais elevados para o suplemento de ingestão média na fase de acabamento em confinamento. Suplementos de ingestão média aumentam a produtividade animal durante a fase de crescimento em pastagens e o desempenho em confinamento de bovinos provenientes de sistemas intensivos de produção. RESUMO 0,12 012 0 12 (0,1 gkg g PC, PC , energéticoproteico energético proteico 1,26 126 1 26 (1,2 3,76 376 3 76 (3,7 PC. . forrageiro piquetes. piquetes (piquetes) utilizandose se animais. (animais) 15 (1 5 1, idade 3648 364 8 364, 217 21 7 21, inicial utilizados recria única seca (FDN forragem 0,1 01 (0, 1,2 2 (1, 3,7 37 (3, (piquetes (animais ( 36 0, (0 3, (3

Resumen Este estudio tiene como objetivo analizar la variación espacio-temporal de los macrocrustáceos de la laguna Morales (LM), Tamaulipas. Se recolectaron muestras en mangle rojo (Rhizophora mangle) y pastos marinos (Halodule wrightii) de 4 sitios y en cada uno se determinaron parámetros fisicoquímicos. Se identificaron en total 22 especies entre ambas comunidades. La diversidad de especies fue de 18 en pastos marinos mientras que en mangle fue de 17. Las especies más abundantes y comunes fueron los anfípodos Orchestia gammarella, Gammarus mucronatus y el camarón carideo Palaemon pugio. La abundancia de organismos fue mayor en pastos marinos con 1,481 ejemplares a diferencia del manglar con 379. Por temporada, la abundancia fue mayor en secas con 1,395 ejemplares, seguido de lluvias (262) y nortes con 181. Índices de riqueza y diversidad fueron utilizados para evaluar la diversidad y abundancia. Se estimó una curva de acumulación de especies para ambas comunidades resultando una eficiencia de muestreo mayor del 90%. La importancia de este estudio radica en que existen pocos estudios taxonómicos y ecológicos de crustáceos en este sitio, siendo prácticamente nulos aquellos de variación espacio temporal.

Abstract The aim of this study is to analyze the spatio-temporal variation of macrocrustaceans from Morales Lagoon (LM), Tamaulipas. Samples were collected among red mangrove (Rhizophora mangle) and seagrass (Halodule wrightii) from 4 sites. In each community physicochemical parameters were determined. A total of 22 species were identified among both communities. The maximum species diversity was 18 for seagrasses while in mangrove it was 17 species. The most abundant and common species were the amphipods Orchestia gammarella, Gammarus mucronatus and the caridean shrimp Palaemon pugio. The abundance of organisms was greater in seagrass with 1,481 while in the mangrove was 379 specimens. The abundance was greater in dry season with 1,395 specimens, followed by rainy season (262) and “nortes” season (181). Richness and diversity indices were used to assess species diversity and abundance. A species accumulation curve was estimated for both communities resulting in a sampling efficiency greater than 90%. The importance of this study lies in the fact that there are few taxonomic and ecological studies of crustaceans in this site, being those which deal with the spatial and temporal variation of taxa practically nonexistant.