ABSTRACT: This study assessed the impact of total mixed ration silage of Megathyrsus maximus harvested with 70 cm composed of Megathyrsus maximus harvested at 70 cm in height and concentrate at the time of silage or total mixed ration of grass cut at 70 cm composed of Megathyrsus maximus harvested with 70 cm in height (in Exp. I and III) and total mixed ration silage cut at 130 cm composed of Megathyrsus maximus harvested 130 cm height and concentrate at the time of silage or total mixed ration of Megathyrsus maximus harvested with 130 cm composed of Megathyrsus maximus harvested at 130 cm height (in Exp. II and IV), on rumen metabolism, nutrient digestibility, and the performance and carcass characteristics of feedlot lambs. The results showed that TMRS70 increased ruminal pH in Exp. I and TMRS130 exhibited higher ether extract digestibility, propionic concentration, and lower acetic to propionic ratio and ruminal pH compared to TMR130 in Exp. II. In Exp. III and IV, there was no significant effect on the performance and quality of the carcass. However, in Exp. IV, TMRS130 led to decreased dry matter intake and average daily gain, while lambs fed with TMR130 showed a higher rib-eye area. Total ration ensilage could be used as a conservation method for young grasses (70 cm) without impairing performance, metabolism, carcasses, and meat quality. However, further research is recommended to evaluate the economic analysis of feeding total ration ensilage (70 cm) instead of total mixed ration as a forage conservation method. ABSTRACT 7 Exp 13 IV , IV) metabolism digestibility TMRS TMRS7 TMRS13 concentration TMR TMR13 However gain ribeye rib eye area (7 carcasses 1 TMRS1 TMR1 (

RESUMO: Este estudo teve como objetivo avaliar o impacto da silagem de ração total de Megathyrsus maximus colhido com 70 cm de altura e concentrado no momento da silagem ou ração total de capim cortado a 70 cm, composta por Megathyrsus maximus colhido com 70 cm de altura (nos Exp. I e III) e silagem de ração total cortada a 130 cm, composta por Megathyrsus maximus colhido com 130 cm de altura e concentrado no momento da silagem ou ração total de Megathyrsus maximus colhido a 130 cm de altura (nos Exp. II e IV), sobre o metabolismo ruminal, a digestibilidade dos nutrientes, e o desempenho e as características de carcaça de cordeiros confinados. Os resultados mostraram que TMRS70 aumentou o pH ruminal no Exp. I, e TMRS130 exibiu maior digestibilidade do extrato etéreo, concentração de propionato e menor razão acético/propionato e pH ruminal em comparação com TMR130 no Exp. II. Nos Exp. III e IV, não houve efeito significativo sobre o desempenho e a qualidade da carcaça. No entanto, no Exp. IV, TMRS130 levou a uma diminuição no consumo de matéria seca e no ganho médio diário, enquanto cordeiros alimentados com TMR130 mostraram uma maior área de olho de lombo. A ensilagem da ração total poderia ser usada como um método de conservação para gramíneas jovens (70 cm) sem prejudicar o desempenho, metabolismo, carcaças e qualidade da carne. No entanto, recomenda-se mais estudos avaliando a análise econômica da alimentação com ensilagem de ração total (70 cm) em vez de ração totalmente misturada como método de conservação de forragem. RESUMO 7 nos Exp 13 IV , IV) nutrientes confinados TMRS TMRS7 TMRS13 etéreo acéticopropionato acético TMR TMR13 entanto diário lombo (7 carne recomendase recomenda se forragem 1 TMRS1 TMR1 (

Abstract Introduction. Livestock farming with Creole cattle is practiced in rural areas with challenging characteristics for species management. Objective. To describe the production system and the socio-cultural and technical-economic factors affecting the production of Nunkiní Creole cattle (Bos taurus). Materials and methods. The study was conducted from November 2020 to October 2021 in nine livestock production units of Nunkiní, Calkiní municipality, Campeche, Mexico. Information was obtained from an interview form with social, cultural, technical, and economic study variables, applied to selected producers. Data were analyzed using descriptive statistics and ANOVA. Results. Livestock farming was carried out by men (100 %), with an average age of 58.44 years. The average years of experience were 34.61. Younger producers had higher levels of education and less experience, and were responsible for the production units of higher technological levels. The size of the livestock production unit ranged from five to twenty-two cattle (average of 14). Feeding management followed a transhumance scheme, with cattle being free-ranging on ejido lands and from May to December and semi-stabled from January to April, grazing on cultivated pastures and supplemented with agricultural residues. With the zootechnical management implemented by the producers, an average pregnancy rate of 83 % was achieved. The main product marketed was fresh meat in cuts and direct sale to consumers, with an average price of 2.675 USD$/kg. Conclusion. It is traditional extensive system that takes advantage of the common use of grasslands. It involves experienced but older producers, with small investments, and serves to strengthen their family economy. This activity is threatened by the lack of revaluation of Creole cattle and the introduction of exotic breeds in the area to maximize production.

Resumen Introducción. La ganadería con bovinos criollos se práctica en espacios rurales con características difíciles para el manejo de las especies. Objetivo. Describir el sistema productivo y los factores socioculturales y técnico-económicos que afectan la producción del bovino criollo de Nunkiní (Bos taurus). Materiales y métodos. El estudio se realizó entre noviembre del 2020 a octubre del 2021, en nueve unidades de producción pecuarias de Nunkiní en el municipio de Calkiní, Campeche, México. La información se obtuvo de una cédula de entrevista con variables de estudio sociales, culturales, técnicas y económicas, aplicada a productores seleccionados. Los datos se analizaron mediante estadística descriptiva y ANDEVA. Resultados. La crianza del ganado la realizaron hombres (100 %), con edad promedio de 58,44 años. Los años de experiencia promedio fueron de 34, 61. Los productores jóvenes tuvieron mayor escolaridad y menor experiencia, y se encargaron de las unidades de producción de mayor nivel tecnológico. El tamaño de la unidad de producción pecuaria varió de cinco a veintidós bovinos (media de 14). El manejo alimenticio tuvo un esquema de trashumancia, donde de mayo a diciembre estuvieron libres en tierras ejidales y de enero a abril se manejaron semiestabulados, con pastoreo en potreros cultivados y suplementados con residuos agrícolas. Con el manejo zootécnico implementado por los productores, se obtuvo un promedio de 83 % de preñez. El producto principal comercializado fue carne fresca en cortes y venta directa al consumidor, con un precio promedio de 2,675 USD$/kg. Conclusión. Es un sistema tradicional extensivo que aprovecha el uso común de los agostaderos. Con productores de experiencia, pero de edad avanzada, de pequeña inversión y le sirve para fortalecer su economía familiar. Dicha actividad se ve amenazada por la falta de revalorización del bovino criollo y la introducción de razas exóticas en la zona para maximizar la producción.

Resumen La cuenca baja del río Acre se ubica en una zona de deforestación con la implementación de pastizales para ganado vacuno en suelos susceptibles a la erosión y clima ecuatorial. La existencia de mataderos y ganado vacuno en el municipio de Boca do Acre, en el estado de Amazonas, es uno de los problemas vinculados a la deforestación en la Amazonía brasileña. Ante este escenario, se presentó una estimación de las pérdidas de suelo con la aplicación de la Ecuación Universal en un sistema de información geográfica. En la metodología, se desarrolló una base de datos con información vectorizada para extraer las áreas de tipos de suelo y cobertura del suelo, incluyendo el análisis espacial de pendientes extraído del modelo digital de elevación. Como resultado del análisis de las áreas por geoprocesamiento y vectorización, se obtuvieron los cálculos de las parcelas de erosión a través de tablas con los parámetros adoptados por los referentes científicos. Se encontró que el 60% de la pérdida de suelo ocurre en el área agrícola en el 11% del territorio de la cuenca, siendo predominantemente en áreas de asentamientos rurales en el estado de Acre. Como resultado de la estimación, la pérdida de suelo en la cuenca baja del río Acre fue de 386.422 t/ha/año, con una producción de 46 millones de toneladas de sedimentos por año.

Abstract The Lower Acre River Basin is located in an area of deforestation with the implementation of pastures for beef cattle ranching in soils susceptible to erosion and equatorial climate. The existence of slaughterhouses and beef cattle in the municipality of Boca do Acre, in the state of Amazonas, is one of the problems linked to deforestation in the Brazilian Amazon. Given this scenario, an estimate of soil losses was presented with the application of the Universal Equation in a geographic information system. In the methodology, a database was elaborated with vectorized information for the extraction of the areas of the types of soils and land cover, including the spatial analysis of slopes extracted from the digital elevation model. Due to the analysis of the areas by geoprocessing occurring by vectorization, the calculations of the erosion plots were obtained through tables with the parameters adopted by the scientific references. It was found that 60% of the soil loss occurs in the area of agriculture in 11% of the territory of the watershed, being predominantly in areas of rural settlements of the state of Acre. As a result of the estimate, soil loss in the Lower Acre River Basin was 386,422 t/ha/year, with a production of 46 million tons of sediment per year.

Resumo A Bacia do Baixo Rio Acre está localizada em uma área de desflorestamento com implantação de pastagens para pecuária de corte em solos suscetíveis à erosão e clima equatorial. A existência de abatedouros e pecuária de corte implantada no município de Boca do Acre, no Amazonas, é um dos problemas vinculados ao desmatamento da Amazônia Brasileira. Diante desse cenário, foi apresentada uma estimativa de perdas de solo com aplicação da Equação Universal em sistema de informação geográfica. Na metodologia, foi elaborado um banco de dados com informações vetorizadas para extração das áreas dos tipos de solos e cobertura da terra, incluindo a análise espacial de declividades extraídas do modelo digital de elevação. Em decorrência da análise das áreas pelo geoprocessamento ocorrer pela vetorização, foram obtidos os cálculos das parcelas de erosão através de tabelas com os parâmetros adotados pelas referências científicas. Foi constatado que 60% da perda de solo ocorrem na área de agricultura em 11% do território da bacia hidrográfica, sendo predominantemente em áreas de assentamentos rurais do estado do Acre. Como resultado da estimativa, a perda de solos na Bacia do Baixo Rio Acre foi de 386.422 t/ha/ano, com uma produção de 46 milhões de toneladas de sedimentos por ano.

RESUMEN El manejo inadecuado de los pastizales ha provocado la degradación de extensas áreas, la pérdida de productividad y sostenibilidad de muchas de ellas, reflejando una realidad común entre los ganaderos de Colombia. Por ello, en la Estación Agraria Paysandú de la Universidad Nacional de Colombia, ubicada en el corregimiento de Santa Elena de la ciudad de Medellín, se realizó una investigación para determinar un índice de calidad del suelo (SQI) mediante la evaluación de los indicadores físicos y químicos más relacionados con el deterioro y producción de materia seca del pasto kikuyo (Cenchrus clandestinus). Se estableció un conjunto mínimo de datos (MDS) para los indicadores más sensibles, elegidos mediante el análisis de componentes principales PCA, y se utilizó una función de puntuación no lineal para obtener el SQI. Se encontraron diferencias estadísticas entre todos los tratamientos y la producción de materia seca (P<0,05: 1,91x10-32). Los indicadores más sensibles fueron: densidad aparente DR > porosidad total TP > macroporos MAC > microporos MIC > resistencia a la penetración PR > capacidad de intercambio catiónico efectiva ECEC > pH. Como resultado, se obtuvo el siguiente SQI = (0,225×BD) + (0,224×TP) + (0,220×MAC) + (0,218×MIC) + (0,113×PR) + (0,0879×ECEC) + (0,0877×pH). Se sugiere probar el índice en praderas dominadas por pasto kikuyo ubicadas en el trópico alto colombiano. La línea de base es crítica a valores > 0,58 Mg m-3 para BD y > 2,25 MPa para PR. Además, el intervalo de pH óptimo para el desarrollo del pasto kikuyo se situó entre 5,4 y 6,4.

ABSTRACT Inadequate grassland management has resulted in the degradation of extensive areas, loss of productivity and sustainability of many of them, reflecting a common reality among livestock farmers in Colombia. Therefore, at the Paysandú Agricultural Station of the Universidad Nacional de Colombia, located in the Santa Elena township of the city of Medellín, a study was carried out to determine a soil quality index (SQI) by evaluating the physical and chemical indicators that were most related to the deterioration and dry matter production of kikuyu grass (Cenchrus clandestinus). A minimum data set (MDS) was established for the most sensitive indicators, selected by principal component analysis (PCA), and a nonlinear scoring function was used to obtain the SQI. Statistical differences were found between all the treatments in relation to dry matter production (P<0.05: 1.91x10-32). The most sensitive indicators were bulk density BD > total porosity TP > macropores MAC > micropores MIC > penetration resistance PR > effective cation exchange capacity ECEC > pH. As a result, the following formula was obtained: SQI = (0.225×BD) + (0.224×TP) + (0.220×MAC) + (0.218×MIC) + (0.113×PR) + (0.0879×ECEC) + (0.0877×pH). This index should be tested in kikuyu grass-dominated pastures located in the Colombian high tropics. The baseline is critical at values > 0.58 Mg m-3 for BD and > 2.25 MPa for PR. In addition, the optimum pH range for kikuyu grass development was between 5.4 and 6.4.

Abstract The objective of this work was to determine the effect of solar radiation intensity of the grazing system on sheep behavior. Treatment 1, consisted of monoculture of natural grasses (47 ± 5 lux), treatment 2 of natural grasses with Leucaena leucocephala trees (34 ± 3 lux) and treatment 3 of natural grasses with Manguifera indica trees (16 ± 3 lux). The total time of each activity per daily session was determined. A completely randomized design was used with a 3x2 factorial arrangement (three intensities of solar radiation, two sessions per day). Grazing behavior was affected by the interaction between factors. The grazing-walking activity was higher in the pastures with lower levels of solar radiation (Leucaena y Manguifera), with 217.50 y 216.38 min, respectively, in the morning session, while all times were lower in the afternoon session, with the lowest result in grazing in the sun (108.05 minutes). The reduction of solar radiation under the treetops favored the behavior of the sheep, which allowed the animals to perform resting and ruminating activities under the shade of the trees, more preferably in the afternoon session.

Resumen El objetivo fue determinar el efecto de la intensidad de radiación solar del sistema de pastoreo en la conducta de ovinos. El tratamiento 1 consistió en: monocultivo de gramíneas naturales (47 ± 5 lux); el 2: gramíneas naturales con árboles de Leucaena leucocephala (34 ± 3 lux); y el 3: gramíneas naturales con árboles de Manguifera indica (16 ± 3 lux). Se determinó el tiempo total de cada actividad por sesión del día. Se utilizó un diseño completamente aleatorizado, con arreglo factorial 3x2 (tres intensidades de radiación solar por dos sesiones del día). La conducta en pastoreo fue afectada por la interacción entre los factores. La actividad pastar-caminar fue mayor en los pastoreos de menor nivel de radiación solar (Leucaena y Manguifera) con 217.50 y 216.38 min respectivamente, en la sesión de la mañana; mientras que todos los tiempos fueron menores en la sesión tarde, con el menor resultado en el pastoreo al sol (108.05 minutos). La reducción de la radiación solar bajo la copa de los árboles favoreció el comportamiento conductual de las ovejas, esto permitió que los animales realizaran actividades de descanso y rumia bajo la sombra de los árboles, con más preferencia en la sesión tarde.

ABSTRACT The beef is one of the main sources of nutrients for a balanced diet. In this context, several authors have reported that grass-fed beef presents low levels of intramuscular fat and high levels of polyunsaturated fatty acids. Some studies have noted that forage fatty acid content is variable between species and their varieties, and that can affect fatty acid profile in beef. The aim of this study was to evaluate beef quality from three different types of pastures in southern Chile. A group of 45 Holstein Friesian steers were finished in the spring months with three different types of pastures from temperate rainy climate: Improved pasture (P), Lolium perenne L.-based pasture (LT), and Lolium multiflorum Lam.-based pasture (LM). The steers were separated into groups of 15 for treatment. Nonsignificant differences were found in carcass measurements and P treatment showed a higher intramuscular content than LM treatment (2.26% vs. 1.42%) and greater presence of SFA: 42.4% vs. 40.3% reported in LM treatment. While LM presented a higher n-6 fatty acids: 4.42% related to P treatment: 3.13%. Regardless of the type of pasture, it can be confirmed that meat from pasture systems presents low intramuscular fat and a better ratio of n-6/n-3.

ABSTRACT Among the problems of physical degradation of soils, compaction and densification are the main ones, and these cause strong decreases in subsequent crop yields. The degradation of the soil structure is a problem today in Cuba, which can occur in all soils and at all levels of livestock production. Taking into account the above, this document aims to expose the main changes produced in the internal structure of soils as a result of its degradation. Soil compaction, due to the collapse or reduction of pore spaces, is the most common cause of physical restriction for root growth and development. As an aggravating factor, the degradation of the soil structure is commonly considered the most difficult type of land degradation to locate and reconvert; the reason is that this degradation is a subsurface phenomenon. Finally, it is about establishing some possible solutions to this problem, among which the main method of restoring the porosity of the limiting layers of root growth and that must take into account the chemical and physical factors of the soil, the species, the type of soil and the degree of degradation of the species that are proposed to restore, the use of plowing v+ harrow or plowing alone is the most efficient method for the recovery of pastures of the species.

RESUMEN Entre los problemas de la degradación física de los suelos, la compactación y el adensamiento son los principales, y estos causan fuertes decrementos en los rendimientos posteriores de los cultivos de los mismos. La degradación de la estructura del suelo es un problema hoy en Cuba, que puede ocurrir en todos los suelos y a todos los niveles de producción pecuaria. Teniendo en cuenta lo anterior, este documento pretende exponer los principales cambios producidos en la estructura interna de los suelos como resultado de su degradación. La compactación del suelo, debido al colapso o disminución de los espacios de poros, es la causa más común de restricción física para el crecimiento y desarrollo de las raíces. Como agravante, la degradación de la estructura del suelo es comúnmente considerada como el tipo de degradación de tierras más difícil de localizar y reconvertir; la razón es que ésta degradación es un fenómeno subsuperficial. Finalmente se trata de establecer algunas posibles soluciones a dicha problemática, entre las cuales el método principal de restauración de la porosidad de las capas limitantes del crecimiento de las raíces y que se deben tener en cuenta los factores químicos y físicos del suelo, la especie, el tipo de suelo y el grado de degradación de las especies que se proponen restaurar, el uso de la aradura + grada o de la aradura sola resulta el método más eficiente para la recuperación de pastizales de las especies

ABSTRACT The intensification of cattle post-weaning phase in tropical pastures depends on supplementation strategies. The objective of this study was to assess the effect of increasing levels of concentrate supplement on the intake, apparent digestibility of nutrients, feeding behavior, and performance of Girolando steers on tropical pasture during the post-weaning phase in the rainy season. Forty uncastrated male Girolando steers, initially weighing 266.62 ± 32.95 kg and aged 11 mo, were allocated into four concentrate supplement levels: 0.2%, 0.3%, 0.4%, and 0.5% body weight. The steers grazed on Urochloa brizantha (Hochst. ex A. Rich.) R.D. Webster ‘Marandu’ pasture. The intakes of supplement DM, non-fibrous carbohydrates (NFC), and total digestible nutrients increased linearly (P < 0.05) with the level of supplement offered to the steers. In a similar response, the apparent digestibility of DM and NFC from the diet also rose linearly (P < 0.05). Grazing time, total feeding time, and total chewing time decreased (P < 0.05) with the increasing levels of concentrate supplementation. In contrast, the time expended on feeding at the trough, biting rate, and the time taken to ruminate each cud increased (P < 0.05) with the supplementation level. Final body weight and average daily gain increased linearly (P < 0.05) with increasing concentrate supplementation. We recommend supplying concentrate supplement at a level of 0.5% of the body weight of steers on tropical pasture during the post-weaning phase in the rainy season.

Abstract Background: Agroforestry systems integrate agricultural, forestry and cultural diversity and have been little studied in coastal regions of Mexico. The SA managed by mixtecs and afro-mexicans are unknown. Questions: Which agroforestry systems are found in Mixtec and Afro-Mexican communities? Which are the forms of management, agricultural and agroforestry practices and useful species in agroforestry systems? Studied species: Various. Study site and dates: Santa María Chicometepec, Cerro de la Esperanza, Collantes, Santa Elena Comaltepec, San Agustín Chayuco, Santiago Tetepec, Oaxaca. October 2021 to October 2022. Methods: Sixty semi-structured interviews were conducted with local specialists in three Mixtec and three Afro-Mexican communities. Questions were asked about traditional agroforestry systems, agricultural, agroforestry and management practices, and useful species. Tours and collections of herbarium specimens were carried out. Each system was described, management and agroforestry practices were categorized; and the number of useful species by category of use and cultural group was recorded. Results: Six agroforestry systems were recorded and described: milpa, pastures, plots, acahuales; piñal and coconut. Agricultural practices in Mixtec communities are carried out with basic tools and inputs and the production is for self-consumption and local sale, while in Afro-Mexican communities they are technical, and their destination is regional sale. The most common agroforestry practices were the boundaries and isolated trees. Conclusions: The cultural groups share agroforestry systems, forms of management, and number of useful species is similar, but they differ in agricultural practices. In the agroforestry systems, edible and timber species (firewood, poles, fences, construction) are mainly conserved.

Resumen Antecedentes: Los sistemas agrosilvícolas (SA) integran diversidad agrícola, forestal y cultural. En regiones costeras de México han sido poco estudiados, particularmente los manejados por mixtecos y afromexicanos de la costa de Oaxaca. Preguntas: ¿Qué SA se encuentran en comunidades mixtecas y afromexicanas?, ¿Cuáles son las especies útiles, formas de manejo, prácticas agrícolas y agroforestales de los SA? Especies de estudio: Diversas. Sitio y años de estudio: Santa María Chicometepec, Cerro de la Esperanza, Collantes, Santa Elena Comaltepec, San Agustín Chayuco, Santiago Tetepec, Oaxaca. Octubre 2021 a octubre 2022. Métodos: Se realizaron 60 entrevistas semiestructuradas a especialistas locales en tres comunidades mixtecas y tres afromexicanas. Se preguntó acerca de especies útiles, sistemas agrosilvícolas, prácticas agrícolas, agroforestales y de manejo. Se realizaron recorridos y colectas de ejemplares de herbario. Se describió cada sistema por sus prácticas agroforestales y de manejo. Se registró el número de especies útiles por categoría de uso y grupo cultural. Resultados: Se documentaron y describieron seis SA: milpa, potreros, solares, acahuales, piñal y cocotal. Las prácticas agrícolas en comunidades mixtecas se realizan con herramientas e insumos básicos y la producción tiene un fin de autoconsumo y venta local, mientras que en comunidades afromexicanas son tecnificadas y su destino es la venta regional. Linderos y árboles aislados fueron las prácticas agroforestales más comunes. Conclusiones: Mixtecos y Afromexicanos comparten SA, formas de manejo y prácticas agroforestales, difieren en las prácticas agrícolas. En los SA se conservan principalmente especies comestibles y maderables. El número de especies útiles es similar en comunidades mixtecas y afromexicanas.

ABSTRACT "In Cuba, agriculture is responsible for 20% of Greenhouse Gas emissions, making it the second largest emitting sector. This research aims to estimate the Greenhouse Gas emissions in the Agriculture sector in the province of Cienfuegos in the period 2010-2020. The methodologies used were the Guidelines of the Intergovernmental Panel on Climate Change of 2006. In 2020, the GHG emissions from the Agriculture sector in the province of Cienfuegos were 309.4 Gg CO2eq (representing a 28.9% decrease compared to 2010). Of these emissions, 60.3% corresponded to methane (CH4), 39.5% to nitrous oxide (N2O), and the remaining 0.1% to carbon dioxide (CO2). CH4 emissions amounted to 186.9 Gg CO2eq and mainly came from enteric fermentation of livestock, which contributed 169.0 Gg CO2eq (90.5% of the total). N2O emissions from the sector amounted to 116.9 Gg CO2eq and mainly came from activities related to agricultural soils, with direct livestock excreta in pastures being the subcategory that contributed the most N2O in the province with 81.3 Gg CO2eq, representing 69.6% of the total. Finally, CO2 emissions solely came from the application of urea. The emissions inventory of the Agriculture sector in the province of Cienfuegos is a valuable tool for making local-level decisions, prioritizing mitigation actions and measures in line with national goals, supporting development, as well as implementing and monitoring the impact of such actions."

RESUMEN En Cuba la agricultura es responsable del 20% de las emisiones de Gases de Efecto Invernadero, siendo el segundo sector más emisor. Esta investigación tiene como objetivo estimar las emisiones de Gases de Efecto Invernadero en el sector Agricultura en la provincia de Cienfuegos en el período 2010-2020. Se utilizaron como metodologías las Directrices del Panel Intergubernamental sobre Cambio Climático del 2006. En 2020, las emisiones de GEI del sector Agricultura en la provincia de Cienfuegos, fueron de 309.4 Gg CO2eq (representa un 28.9% menor que el año 2010). Del total de estas emisiones, el 60.3% correspondió al metano (CH4), el 39.5% al óxido nitroso (N2O) y el restante 0.1% al dióxido de carbono (CO2). Las emisiones de CH4 ascienden a 186.9 Gg CO2eq y provienen principalmente de la fermentación entérica del ganado, actividad que aporta 169.0 Gg CO2eq, (90.5% de las mismas). Las emisiones de N2O del sector ascienden a 116.9 Gg CO2eq y provienen principalmente de las actividades vinculadas a los suelos agrícolas, siendo las excretas directas del ganado en pasturas la subcategoría que más aporta N2O en la provincia con 81.3 Gg CO2eq y representa el 69.6% de ellas. Por último, las emisiones de CO2 provienen en su totalidad de la aplicación de urea. El inventario de emisiones del Sector Agricultura en la provincia de Cienfuegos constituye una herramienta valiosa para tomar decisiones a nivel local, priorizar acciones y medidas de mitigación acorde a las metas nacionales, apoyar el desarrollo, así como implementar y monitorear el impacto de dichas acciones.

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.

RESUMO A Agricultura de Precisão (AP) procura validar ferramentas tecnológicas que permitam captar a variabilidade espacial das culturas e do solo, o que constitui a base para o estabelecimento de zonas homogéneas de gestão (ZHG). Os sensores que medem a condutividade elétrica aparente do solo (CEa) são exemplo destas ferramentas no levantamento da variabilidade espacial das caraterísticas do solo. A estabilidade temporal dos padrões de variabilidade espacial da CEa é essencial para assegurar corretas decisões a médio e longo prazo. Neste estudo, foram usados dois sensores de CEa, um sensor de contacto (Veris 2000 XA) e um sensor de indução eletromagnética (EM-38), em quatro parcelas de pastagens permanentes de sequeiro no Alentejo. O levantamento com o sensor de contacto foi realizado em outubro de 2018 e o levantamento com o sensor de indução foi realizado em setembro de 2020. Este estudo teve como objetivo avaliar a estabilidade temporal dos padrões das ZHG resultantes de medições da CEa com diferentes sensores em diferentes datas. O processamento de dados incluiu a sincronização das coordenadas geográficas obtidas pelos dois sensores em cada parcela e o estabelecimento de ZHG a partir de análise geoestatística, tanto da CEa como da altimetria. Apesar das condições do solo serem diferentes, nomeadamente em termos de humidade, e dos sensores terem uma forma diferente de medição (de contacto versus não contacto), os valores da CEa mostraram correlações estatisticamente significativas em todos os campos experimentais, o que se refletiu na estabilidade dos padrões espaciais das ZHG obtidas. Estes resultados abrem boas perspetivas para futuros desenvolvimentos, os quais deverão ocorrer ao nível dos algoritmos que permitam a validação da variabilidade espacial e da estabilidade temporal da CEa através de amostragem inteligente do solo, conduzindo a recomendações sustentadas ao nível da fertilização ou da correção do solo.

ABSTRACT Precision agriculture (PA) intents to validate technological tools that capture soil and crop spatial variability, which constitute the basis for the establishment of differentiated management zones (MZ). Soil apparent electrical conductivity (ECa) sensors are commonly used to survey soil spatial variability. Temporal stability of the surveys is essential to ensure correct medium and long-term decisions. In this study, an ECa contact-type sensor (Veris 2000 XA) and an electromagnetic induction sensor (EM-38) were used in four fields of dryland pastures in Alentejo region of Portugal. The first survey was carried out in October 2018 and the second was carried out in September 2020. The aim of this study was to assess the temporal stability of ECa patterns using different types of sensors. Data processing involved synchronizing geographic coordinates obtained by the two types of ECa sensors in each location and establishing MZ based on geostatistical analysis of altimetry and ECa data. Although the basic technologies have different principles (contact versus non-contact sensors), the surveys were carried out at different soil moisture conditions and were temporarily separated (about 2 years), ECa measurements showed statistically significant correlation in all experimental fields, which was reflected in spatially stable patterns of the MZ maps. These results provide perspectives for future developments, which will need to occur in the creation of algorithms that allow validating the spatial variability and temporal stability of ECa through smart soil sampling and analysis to allow recommendations for sustained soil amendment or fertilization.

Abstract The management of silvopastoral systems associated with carob trees (Neltuma spp.) as a tree component constitutes a forestry potential for the Chaco ecoregion, in addition to benefiting animal well-being by providing shade, an alternative source of forage, protection against wind and the effects adverse effects of temperature extremes, and mitigate the effects of climate change by storing carbon in both biomass and soil, thus constituting an integrated sustainable production system for the Paraguayan Chaco. The objective was to evaluate the management of the regeneration of carob trees integrated into silvopastoral systems of the Paraguayan Central Chaco. For this, the survival of carob trees subjected to silvicultural treatments in silvopastoral systems was determined, the increase in diameter of carob trees subjected to silvicultural treatments in silvopastoral systems was evaluated, determining the basal area, volume, biomass, accumulated carbon and carbon dioxide, equivalent carbon in the studied systems, study the phenology and health status of the inventoried tree individuals, characterize the herbaceous animal component and determine the physical and chemical properties of the soils of the paddocks under study. The results obtained refer to a high survival of carob trees in silvopastoral systems, with the averages of the dasometric variables in terms of basal area being 11.99 m2/ha, stem volume being 10.93 m3/ha and total volume being 75. 48 m3/ha. At the time of the inventory, it was recorded that 74% of the individuals were in flowering and 68% were sick. The herbaceous component was made up of Gatton panic (Panicum maximun) with an animal load of 0.8 AU and only one of the three paddocks had compacted soils. The accumulated carbon dioxide content was similar in the three pastures. It is concluded that the silvopastoral systems associated with Neltuma spp. As a tree component, they constitute a forest potential for sustainable production in the Chaco ecoregion.

Resumen El manejo de los sistemas silvopastoriles asociados con los algarrobos (Neltuma spp.) como componente arbóreo constituyen un potencial forestal para la ecorregión chaqueña, además de beneficiar al bienestar animal por suministro de sombra, fuente alternativa de forraje, protección contra el viento y los efectos adversos de los extremos de temperatura, y mitigar los efectos del cambio climático por el almacenamiento de carbono tanto en la biomasa como el suelo, por lo que constituye un sistema integrado de producción sustentable para el Chaco paraguayo. El objetivo fue evaluar la regeneración natural de algarrobos (Neltuma spp.) integrados a sistemas silvopastoriles del Chaco Central Paraguayo como respuesta manejo silvicultural. Para ello, se determinó la sobrevivencia de algarrobos sometidos a tratamientos silviculturales en sistemas silvopastoriles, se evaluó el incremento en diámetro de algarrobos, el área basal, el volumen, la biomasa, el carbono acumulado y dióxido de carbono equivalente, la fenología y el estado sanitario de los individuos arbóreos inventariados, el componente herbáceo y animal, y las propiedades físicas y químicas de los suelos. Los resultados obtenidos refieren una sobrevivencia alta de algarrobos en los sistemas silvopastoriles, siendo los promedios de las variables dasométricas en cuanto a área basal de 11,99 m2/ha, volumen de fuste de 10,93 m3/ha y del volumen total 75,48 m3/ha. Al momento del inventario se registró que 74% de los individuos se encontraban en floración y 68% enfermos. El componente herbáceo estuvo integrado por Gatton panic (Panicum maximun) con una carga animal de 0,8 UA y solo uno de los tres potreros presentó suelos compactados.El contenido de anhidrido carbónico acumulado fue similar en los tres potreros. Se concluye que los sistemas silvopastoriles asociados con Neltuma spp. como componente arbóreo constituyen un potencial forestal para producción sustentable de la ecorregión chaqueña.

Abstract Pastures is important for livestock production, are source of food mainly for ruminant livestock. The study was conducted in grasslands of the highlands of Puno, Peru, at an altitude of 3818 masl. The objective was to determine the effect of revegetation with two native grasses: Festuca dolichophylla Presl "chilligua" (Fedo) and Poa gilgiana Pilger "K'achu" (Pogi) in the recovery of degraded pastures with the addition of sheep manure as a source of organic matter (OM), conducted under a split-plot design whose study factors were 2 native species, 2 fertilization factors with and without the addition of sheep feces and urine (OM), in 3 blocks; The results indicate that the highest growth and biomass yield was for Fedo, probably due to its adaptive capacity, the green matter yield of Fedo and Pogi was higher in the treatment with the addition of OM, the incorporation of manure to the pasture had a positive influence on the recovery of the pasture, on the other hand Fedo had a greater height than Pogi; Likewise, the seed production of the treatments with added OM was higher than the treatments without OM; the protein content with addition of OM was higher in both species and the NDF was higher in the species without addition of OM; the application of OM favored the growth and nutritive value of the species. It was concluded that revegetation and incorporation of sheep manure had a favorable effect on the recovery and nutritional quality of the pasture.

Resumen Los pastizales naturales son importantes para la producción ganadera, son fuente de alimentación principalmente para el ganado rumiante. El estudio se realizó en pajonales del altiplano de Puno Perú a una altitud de 3818 msnm el objetivo fue determinar el efecto de la revegetación con dos gramíneas nativas: Festuca dolichophylla Presl “chilligua” (Fedo) y Poa gilgiana Pilger “K´achu” (Pogi) en la recuperación de pastizales degradados con adición de estiércol de ovino como fuente de materia orgánica (MO), conducido bajo el diseño de parcelas divididas cuyos factores de estudio fueron 2 especies nativas, 2 factores de abonamiento con y sin adición de (MO) heces y orina de ovino, en 3 bloques; los resultados indican que el mayor crecimiento y rendimiento de biomasa fue para Fedo probablemente por su capacidad de adaptación, rendimiento de materia verde de Fedo y Pogi fue superior en el tratamiento con adición de MO, la incorporación de estiércol al pastizal influyo positivamente en la recuperación del pasto, por otra parte Fedo resulto con mayor altura que Pogi;; la producción de semilla de los tratamientos adicionados con MO fueron superiores a los tratamientos sin aporte de MO; el contenido de proteína con adición de MO fue mayor en ambas especies, la FDN fue mayor en las especies sin adición de MO, la aplicación de MO favoreció el crecimiento y el valor nutritivo de las especies. Se concluye que la revegetación e incorporación de estiércol de ovino tuvo un efecto favorable en la recuperación y calidad nutritiva del pastizal.

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.