ABSTRACT The proper disposal of fruit and vegetable waste is essential to promote environmental sustainability, reduce the carbon footprint, improve soil quality, and contribute to the transition to a circular economy. This study examined the impact of incorporating dairy cattle wastewater (DCWW) into anaerobic co-digestion with fruit and vegetable residues and utilization of the resulting biofertilizer as a diluent in the anaerobic mono-digestion of fruit and vegetable residues (recycle). The specific biogas and methane production and the agronomic quality of the biofertilizer were evaluated in a semi-continuous trial. Two startup strategies were employed: initially, the reactors were entirely fed with inoculum (biofertilizer derived from DCWW), and fruit and vegetable residue feedstock was gradually introduced. Anaerobic co-digestion of fruit and vegetable residues with DCWW yielded the highest specific production of biogas and methane at 720 and 436 L kg-1 of volatile solids (VS), respectively. The addition of DCWW increases fruit and vegetable residue alkalinity by 249% and reduces the volatile acidity by 83.4%. Anaerobic mono-digestion of fruit and vegetable residues enhances macronutrient recovery in the biofertilizer through recycle. Logistically, directing fruit and vegetable residues to rural areas for anaerobic co-digestion with DCWW promotes agricultural biofertilizer use. sustainability footprint economy (DCWW codigestion co digestion monodigestion mono recycle . (recycle) semicontinuous semi continuous trial employed initially DCWW, , DCWW) introduced 72 43 kg1 kg 1 kg- VS, VS (VS) respectively 249 834 83 4 83.4% Logistically use (recycle 7 (VS 24 8 83.4 2 83.

RESUMO A destinação adequada dos resíduos de frutas e vegetais é fundamental para promover a sustentabilidade ambiental, reduzir a pegada de carbono, melhorar a qualidade do solo e contribuir para a transição para uma economia circular. Neste estudo, foram avaliados os efeitos da adição de água residuária da bovinocultura de leite em codigestão anaeróbia com resíduos de frutas e vegetais e o uso do biofertilizante como diluente na monodigestão anaeróbia dos resíduos de frutas e vegetais (reciclo). A produção específica de biogás e metano, bem como a qualidade agronômica do biofertilizante em um estudo semicontínuo, foram avaliados. Foram utilizadas duas estratégias para partida dos reatores: o abastecimento inicial dos reatores totalmente com inóculo (biofertilizante proveniente da digestão anaeróbia da água residuária da bovinocultura de leite) e a progressão de carga para os resíduos de frutas e vegetais. A maior produção específica de biogás e metano foi atingida pela codigestão anaeróbia de resíduos de frutas e vegetais com água residuária da bovinocultura de leite, 720 e 436 L kg-1 de sólidos voláteis (SV), respectivamente. A adição da água residuária da bovinocultura de leite aumentou em 249% a alcalinidade dos resíduos de frutas e vegetais e diminuiu em 83,4% sua acidez volátil. A recuperação de macronutrientes no biofertilizante é favorecida pela monodigestão anaeróbia dos resíduos de frutas e vegetais em função do uso do reciclo. Entretanto, visando a destinação destes ao meio rural, a codigestão anaeróbia com água residuária da bovinocultura de leite favorece o uso agrícola do biofertilizante. ambiental carbono circular reciclo . (reciclo) semicontínuo 72 43 kg1 kg 1 kg- SV, SV , (SV) respectivamente 249 834 83 4 83,4 volátil Entretanto rural (reciclo 7 (SV 24 8 83, 2

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 chemical characteristics of Cenchrus clandestinus grass, nutritional base in dairy production systems, demand the energy supplementation. Corn grain is the most used food for this purpose, but considering its demand and prices, the aim of this study was to evaluate its partial replacement by alternative non-fibrous carbohydrates sources on methane emissions, energy and nitrogen balance and productive performance of dairy cows. Sixteen multiparous Holstein cows were fed Cenchrus clandestinus plus one of four concentrate supplements formulated with corn (Zea mays) or a partial replacement of corn with sorghum (Sorghum vulgare), cassava (Manihot esculenta) or citrus pulp (Citrus sp). Inclusion of these ingredients did not affect dry matter intake, dry matter digestibility, enteric methane emissions, energy and nitrogen balance, milk yield or composition. The results allow to conclude that these ingredients can partially replace corn in the diet of lactating dairy cows.

RESUMEN Las características químicas del pasto Cenchrus clandestinus, base alimenticia en los sistemas de producción lechera, hacen necesaria la suplementación energética. El grano de maíz es el alimento más empleado para este propósito, pero dada su demanda y precio, el objetivo de este trabajo fue evaluar su reemplazo parcial por otras fuentes de carbohidratos no fibrosos sobre la emisión de metano, el balance energético-nitrogenado y el desempeño productivo de vacas lecheras. Dieciséis vacas Holstein recibieron Cenchrus clandestinus y uno de cuatro concentrados formulados con maíz (Zea mays) y sorgo (Sorghum vulgare), yuca (Manihot esculenta) o pulpa cítrica (Citrus sp) en reemplazo parcial del maíz. La inclusión de estos ingredientes no alteró el consumo de materia seca ni su digestibilidad, producción de metano, balance energético-nitrogenado, producción de leche o su composición. Los resultados permiten concluir que esos ingredientes pueden reemplazar parcialmente al maíz en la dieta de vacas lecheras.

ABSTRACT Introduction: In Cuba, there is a tendency to decentralize productions with the creation of livestock modules where different livestock species coexist, such as swine, cattle and poultry. In this context, anaerobic digestion (AD) is an alternative for the decarbonization of the agricultural sector, since it generates energy during waste treatment. Objective: To evaluate the AD of swine manure (SM) and poultry manure (PM) with cattle manure (CM) in terms of biochemical methane potential (BMP), and kinetic parameters in mono and co-digestion. Materials and Methods: The trial was conducted in 2 L reactors at 27 °C (average). The BMP of SM, PM and CM was determined in mono-digestion, and then with addition of 15, 30 and 45 % of CM, to the PM40:SM60 mixture. To describe the kinetic behavior of the process, experimental data were fitted to three first and second order models. Results and Discussion: The experimental BMP with CM addition was higher than expected, with increase between 26-31 %, demonstrating the synergy of the mixtures; since the C/N ratio and the methanogenic archaeal community were improved. The models were adjusted to the experimental data with adjusted coefficients of determination higher than 90 %. Conclusions: The addition of CM increased the experimental methane yield over the expected one. The Hill model shows a maximum yield of 369 LCH4/kgVS for mixtures with 15 and 30 % CM. The best variant was with 15 %, and it is necessary to transport manure from 20 cows to the biodigester.

RESUMEN Introducción: En Cuba, existe tendencia a descentralizar producciones con la creación de módulos pecuarios donde coexisten diferentes especies de ganado, como porcino, vacuno y avícola. En este contexto, la digestión anaerobia (DA) resulta una alternativa para la descarbonización del sector agropecuario, ya que genera energía durante el tratamiento de residuales. Objetivo: Evaluar la DA de estiércol porcino (EP) y gallinaza (EG) con estiércol vacuno (EV) en términos del potencial bioquímico de metano (PBM), y parámetros cinéticos en mono y codigestión. Materiales y Métodos: El ensayo se realizó en reactores de 2 L a 27 ºC (promedio). Se determinó el PBM del EP, EG y EV en monodigestión, y luego con adición de 15, 30 y 45 % de EV, a la mezcla EG40:EP60. Para describir el comportamiento cinético del proceso, se ajustaron los datos experimentales a tres modelos de primero y segundo orden. Resultados y Discusión: El PBM experimental con adición de EV fue superior al esperado, con incremento entre 26-31 %, demostrando la sinergia de las mezclas; ya que se mejoró la relación C/N y la comunidad de arqueas metanogénicas. Los modelos se ajustaron a los datos experimentales con coeficientes de determinación ajustado superiores al 90 %. Conclusiones: La adición de EV aumentó el rendimiento de metano experimental respecto al esperado. El modelo de Hill muestra un rendimiento máximo de 369 LCH4/kgSV para las mezclas con 15 y 30 % de EV. La mejor variante fue con 15 %, y se necesita transportar estiércol de 20 vacas al biodigestor.

Abstract This paper aims to analyze the relationship between agricultural methane and nitrous oxide emissions as a function of per capita gross domestic product (GDP) and its quadratic term in 26 Latin American and Caribbean countries (1990-2019). It also considers the stock of foreign investment to test the polluting paradise hypothesis, agricultural land (AL), and, additionally, methane for nitrous function. The study comprised unit root and cointegration tests. Coefficients were estimated using fully modified least squares (FMOLS), correlated common effects (CCE), and augmented mean group (AMG). Results by FMOLS show statistical evidence of an environmental Kuznets curve in the set of countries for methane and support the polluting paradise hypothesis. However, results from CCE and AMG show the opposite. For nitrous oxide, FMOLS support a U-shaped curve. The above supports a joint environmental policy for both gases, where al is a key element. The previous results must be corroborated with other methods and the studies extended to other countries over time.

Resumen Este trabajo analiza la relación de emisiones agrícolas de metano y óxido nitroso en función del producto interno bruto per cápita y su término cuadrático en 26 países latinoamericanos y del Caribe (1990-2019); considera también el stock de inversión extranjera para probar hipótesis del paraíso contaminante, la superficie agrícola (SA) y el metano para la función de óxido nitroso. El estudio comprendió pruebas de raíz unitaria y cointegración. La estimación de coeficientes se realizó por mínimos cuadrados completamente modificados (FMOLS), efectos comunes correlacionados (CCE) y grupo medio aumentado (AMG). Los resultados por FMOLS muestran evidencia de una probable curva ambiental de Kuznets en el conjunto de países para metano, además sustentan un paraíso contaminante. Los resultados por CCE y AMG indican lo contrario. Para óxido nitroso los resultados de FMOLS apoyan una curva en U. Lo anterior sostiene una política ambiental conjunta de ambos gases, donde la SA es un elemento clave. Los resultados anteriores se tienen que corroborar con otros métodos y extender los estudios a otros países en el tiempo.

Abstract The objective was to evaluate the increasing use of garlic, sesame, and cinnamon oil in the production of CH4 in 60 d in vitro regrowth of Koronivia grass. The addition of 0, 2.5, 5.0, 5.0, 7.5, and 10 % garlic, cinnamon, or sesame oil was evaluated in an in vitro fermentation using a 60-d regrowth of Koronivia grass as substrate. The variables evaluated were cumulative CH4 production at 12, 24, 36, 36, 48, and 72 h; dry matter degradation (DMD), and CH4 production kinetics estimators (A= CH4 production potential, b= CH4 production rate constant, and k= lag time). The CH4 production and the DMD were analyzed with a completely randomized experimental design and orthogonal contrast. The estimators were subjected to a descriptive analysis. An increase of garlic oil and cinnamon linearly reduced CH4 production at 12, 24, 36, 48, and 72 h. The DMD decreased linearly with the use of any of the three oils (P<0.05). The highest value of A was obtained with 2.5 % garlic oil, and the highest value of k and b, with 10 % cinnamon oil. In conclusion, the use of garlic and cinnamon oils resulted in a linear decrease of Koronivia grass CH4 and Koronivia grass DMD under in vitro conditions.

Resumen El objetivo fue evaluar el uso creciente de aceite de ajo, ajonjolí y canela en la producción de CH4 in vitro de pasto llanero con 60 días de rebrote. Se evaluó la adición de 0, 2.5, 5.0, 7.5 y 10 % de aceite de ajo, canela o ajonjolí en una fermentación in vitro usando como sustrato pasto llanero con 60 días de rebrote. Las variables evaluadas fueron producción acumulada de CH4 a las 12, 24, 36, 48 y 72 h, degradación de materia seca (DMS) y los estimadores de cinética de producción de CH4 (A= potencial de producción de CH4, b= tasa constante de producción de CH4 y k= tiempo lag). La producción de CH4 y DMS se analizaron con un diseño experimental completamente al azar y contraste ortogonal. Los estimadores fueron un análisis descriptivo. El aumento de aceite de ajo y canela redujo linealmente la producción de CH4 a las 12, 24, 36, 48 y 72 h. La DMS disminuyó linealmente con cualquiera de los tres aceites (P<0.05). El mayor valor de A fue con 2.5 % de aceite de ajo, el mayor valor de k y b fue con 10 % de aceite de canela. En conclusión, el uso de aceites de ajo y canela mostraron una disminución lineal de la producción de CH4 y DMS de pasto llanero en condiciones in vitro.

Abstract Biogas production through co-digestion of two or more waste products has garnered increasing attention from researchers seeking to optimize this process. Biogas and methane production increase with the addition of glycerol to agro-industrial wastes during anaerobic biodigestion. However, the utilization of a two-phase process focused on hydrogen production has not been widely explored. This work aims to evaluate two-phase anaerobic biodigestion of cassava wastewater by adding residual glycerol and swine wastewater to enhance hydrogen and methane production. A pilot-scale biodigester was used during the acidogenic phase at 38.5°C, containing 4% glycerol. The effluent was submitted to methanogenic treatment, and the influence of temperature (36.0 to 39.0°C) and sodium bicarbonate concentration (2.0 to 6.0 g L-1) were evaluated. The results indicated that the optimum conditions during the methanogenic phase were 39.0°C with a sodium bicarbonate concentration of 5.0 g L-1. The two-phase biodigestion produced 30.8 mL of (H2) RCOD-1 and 104.5 mL of (CH4) RCOD-1. Thus, the substrates and inoculum used were adequate for the anaerobic biodigestion process, increasing the energetic efficiency of the process due to hydrogen production. codigestion co digestion agroindustrial agro industrial However twophase explored pilotscale pilot scale 385C C 38 5 38.5°C 4 treatment 36.0 360 36 0 (36. 390C 39 2.0 20 2 (2. 60 6 6. L1 L 1 L-1 evaluated 50 5. L1. 1. 308 30 8 30. H2 H (H2 RCOD1 RCOD RCOD- 1045 104 104. CH4 CH (CH4 RCOD1. Thus 3 36. (36 2. (2 L- (H 10 (CH (3 (

RESUMO A produção de biogás por meio da codigestão de dois ou mais resíduos tem atraído atenção crescente de pesquisadores que buscam otimizar esse processo. A adição de glicerol aos resíduos agroindustriais durante a biodigestão anaeróbica tem demonstrado aumentar a produção de biogás e metano. No entanto, a utilização de um processo em duas fases focado na produção de hidrogênio ainda não foi amplamente explorada. Este trabalho visa avaliar a biodigestão anaeróbica em duas fases de águas residuais de mandioca, adicionando glicerol residual e águas residuais suínas para aumentar a produção de hidrogênio e metano. Um biodigestor em escala piloto foi utilizado durante a fase acidogênica a 38,5°C, contendo 4% de glicerol. O efluente foi submetido a tratamento metanogênico, e a influência da temperatura (36,0 a 39,0°C) e da concentração de bicarbonato de sódio (2,0 a 6,0 g L⁻¹) foi avaliada. Os resultados indicaram que as condições ótimas durante a fase metanogênica foram 39,0°C com uma concentração de bicarbonato de sódio de 5,0 g L⁻¹. A biodigestão em duas fases produziu 30,8 mL de H₂ por RCOD⁻¹ e 104,5 mL de CH₄ por RCOD⁻¹. Assim, os substratos e o inóculo utilizados foram adequados para o processo de biodigestão anaeróbica, aumentando a eficiência energética do processo devido à produção de hidrogênio. metano entanto explorada mandioca 385C C 38 5 38,5°C 4 metanogênico 36,0 360 36 0 (36, 390C 39 2,0 20 2 (2, 60 6 6, L⁻¹ L¹ L ¹ avaliada 50 5, 308 30 8 30, H RCOD¹ RCOD RCOD⁻ 1045 104 104, CH Assim 3 36, (36 2, (2 L⁻ 10 (3 ( 1

ABSTRACT: The objective of this study was to assess the oxygen pulse and heart rate method (O2P-HR) using a respiration chamber at different measurement times for estimate the heat production (HP) of lambs fed increasing levels of sunflower meal in their diet. Twenty-four lambs were assigned to four experimental diets (0, 100, 200, and 300 g of sunflower meal kg-1 DM). Heat production was estimated using the O2P-HR (HPO2P) method and a respirometry chamber (HPRC). Measurements were obtained by simultaneously measuring heart rate (HR) and oxygen consumption over 3, 6, 9, 12, 15, 18, 21 and 24 h. A flow-through respirometry chamber for small ruminants was used to determine oxygen consumption (VO2) and carbon dioxide and methane production. Data on dietary treatment, measurement times and their interactions were analyzed as repeated measures using mixed model procedures and Restricted Maximum Likelihood (REML) estimation. The Pearson’s correlation coefficient was used to compare techniques. There was no effect of the different levels of sunflower meal inclusion on VO2 and heat production. The HPO2P (126.16 kcal/ BW0.75/day) was 2% higher than that of the HPRC (124.61 kcal/ BW0.75/day), and the correlation coefficients was 0.628. The coefficient of variation was greater for the HPO2P (21.33%) than for HPRC (11.44%). HR (beats/min), VO2 (mL/min/BW0.75) and O2P-HR (mL/beat) required measurement times of 24, 15 and 9 hours, respectively. A measurement time of 24 h was necessary to ensure a more accurate estimate of the heat production using the O2P-HR method. ABSTRACT O2PHR OPHR O2P O P (O2P-HR HP (HP diet Twentyfour Twenty 0, 0 (0 100 200 30 kg1 kg 1 kg- DM. DM . DM) HPOP HPO (HPO2P HPRC. (HPRC) (HR 3 6 12 18 2 flowthrough flow through VO (VO2 treatment REML (REML estimation Pearsons Pearson s techniques 126.16 12616 126 16 (126.1 kcal BW0.75/day BW075day BWday BW0 75 day BW 124.61 12461 124 61 (124.6 BW0.75/day, , 0628 628 0.628 21.33% 2133 33 (21.33% 11.44%. 1144 11.44% 11 44 (11.44%) beats/min, beatsmin beats/min beats min (beats/min) mL/min/BW0.75 mLminBW075 mLminBW mL (mL/min/BW0.75 mL/beat mLbeat beat (mL/beat hours respectively PHR OP ( 10 20 (HPRC (VO 126.1 1261 (126. 7 124.6 1246 (124. 062 62 0.62 21.33 213 (21.33 114 11.44 4 (11.44% (beats/min mL/min/BW0.7 mLminBW07 (mL/min/BW0.7 126. (126 124. (124 06 0.6 21.3 (21.3 11.4 (11.44 mL/min/BW0. mLminBW0 (mL/min/BW0. (12 0. 21. (21. 11. (11.4 mL/min/BW0 (mL/min/BW0 (1 (21 (11. mL/min/BW (mL/min/BW (2 (11

RESUMO: O objetivo com este estudo foi avaliar o método do pulso de oxigênio (O2P-FC) usando câmara respirométrica em diferentes tempos de medição para estimar a produção de calor de cordeiros alimentados com níveis crescentes de farelo de girassol na dieta. Vinte e quatro cordeiros foram distribuídos em quatro dietas experimentais (0,10, 20 e 30% de farelo de girassol). A produção de calor foi estimada pelo método de O2P-FC (PCO2P) e por câmara respirométrica (PCCR). As estimativas foram obtidas medindo-se simultaneamente a frequência cardíaca (FC) e o consumo de oxigênio (VO2) durante 3, 6, 9, 12, 15, 18, 21 e 24 horas. Uma câmara de respirométrica para pequenos ruminantes foi usada para determinar o VO2 e a produção de dióxido de carbono e metano. Os dados referentes a dieta experimental, tempos de medição e suas interações foram analisados como medidas repetidas usando os procedimentos de modelo misto e estimativa de máxima verossimilhança restrita. A correlação de Pearson foi usada para comparar as duas técnicas de estimativa da produção de calor. Não houve efeito dos diferentes níveis de inclusão de farelo de girassol sobre o consumo de oxigênio e produção de calor dos animais. A PCO2P (126,16 kcal/ PV0.75/dia) foi 2% maior que a PCCR (124,61 kcal/ PV0.75/dia), e o coeficiente de correlação foi de 62,8%. O coeficiente de variação foi maior para PCO2P (21,33%) comparado com PCCR (11,44%). A FC (batimentos/min), VO2 (mL/min/PC0,75) e o O2P-FC (mL/batimento) requerem tempos de medição de 24, 15 e 9 horas, respetivamente. É necessário a mensuração por 24 horas para garantir uma estimativa mais precisa da produção de calor usando o método de O2P-FC. RESUMO O2PFC OPFC O2P P (O2P-FC 0,10, 010 0 10 (0,10 2 30 girassol. . girassol) PCOP PCO (PCO2P PCCR. (PCCR) medindose medindo se (FC VO (VO2 3 6 12 18 metano experimental restrita animais 126,16 12616 126 16 (126,1 kcal PV0.75/dia PV075dia PVdia PV0 75 dia PV 124,61 12461 124 61 (124,6 PV0.75/dia, , 628 62 8 62,8% 21,33% 2133 33 (21,33% 11,44%. 1144 11,44% 11 44 (11,44%) batimentos/min, batimentosmin batimentos/min batimentos min (batimentos/min) mL/min/PC0,75 mLminPC075 mLminPC mL PC0 PC (mL/min/PC0,75 mL/batimento mLbatimento batimento (mL/batimento 1 respetivamente O2PFC. FC. PFC OP 0,10 01 (0,1 (PCCR (VO 126,1 1261 (126, 7 124,6 1246 (124, 62,8 21,33 213 (21,33 114 11,44 4 (11,44% (batimentos/min mL/min/PC0,7 mLminPC07 (mL/min/PC0,7 0,1 (0, 126, (126 124, (124 62, 21,3 (21,3 11,4 (11,44 mL/min/PC0, mLminPC0 (mL/min/PC0, 0, (0 (12 21, (21, 11, (11,4 mL/min/PC0 (mL/min/PC0 ( (1 (21 (11, mL/min/PC (mL/min/PC (2 (11

Resumo Diversas discussões têm surgido a respeito da energia proveniente de usinas hidrelétricas ser considerada uma energia limpa e seus reservatórios têm sido investigados devido à grande emissão de gases de efeito estufa (GEE), como dióxido de carbono, metano e óxido nitroso. O presente trabalho traz um estudo estatístico das emissões difusivas de CO2 antes da formação do reservatório da usina hidrelétrica (UHE) de SINOP, Brasil. Investigou-se a associação entre as emissões coletadas na superfície (água-ar) e no fundo do reservatório (sedimento-água) durante quatro campanhas de coletas de dados, realizadas no período de novembro de 2017 até setembro de 2018. Este estudo visa comparar o efeito da profundidade do reservatório no fluxo difusivo de CO2 em 34 pontos de coleta. A variável profundidade analisada foi definida a partir de pontos coletados na superfície e no fundo do reservatório. O objetivo é detectar se épocas de tempo diferentes e se a profundidade do reservatório tem impacto direto no comportamento das emissões difusivas de CO2. Como as medidas da unidade observacional são observadas repetidamente, tem-se uma estrutura multinível, os indivíduos são independentes entre si, porém existe uma correlação intra-indivíduos. Considerando essa configuração de dados, foi feita uma estimação de equações generalizadas (Generalized Estimating Equations – GEE) que é uma técnica que estima a matriz de correlação intra-indivíduos e assim, produz estimativas para os parâmetros dos modelos de regressão generalizados (Generalized Regression Models – GLM) que não sejam enviesadas. O estudo mostrou que as médias das emissões difusivas de CO2 são maiores na superfície do reservatório. O estudo também detectou que em média, existem mais emissões durante o período de chuva na região do que durante a época da estiagem.

Abstract Several discussions have arisen about energy from hydroelectric plants being considered clean energy and its reservoirs have been investigated due to the large emission of greenhouse gases (GHG), such as carbon dioxide, methane, and nitrous oxide. The present work shows a statistical study of the diffusive CO2 emissions before the formation of the reservoir of the hydroelectric power plant (HPP) of SINOP, Brazil. The association between emissions collected at the surface (water-air) and at the bottom of the reservoir (sediment-water) was investigated during four data collection campaigns, carried out from November 2017 to September 2018. This study aims to compare the effect of reservoir depth on the diffusive flow of CO2 at 34 collection points. The variable depth analyzed was defined from points collected on the surface and bottom of the reservoir. The objective is to detect whether different periods of time and whether the depth of the reservoir have a direct impact on the behavior of diffusive CO2 emissions. As the measurements of the observational unit are repeatedly observed, there is a multilevel structure, individuals are independent of each other, but there is an intra-individual correlation. Considering this data configuration, an estimation of generalized equations (GEE) was performed, which is a technique that estimates the intra-individual correlation matrix and thus produces estimates for the parameters of the generalized regression models (Generalized Regression Models – GLM) that are not biased. The study showed that the average diffusive CO2 emissions are higher on the reservoir surface. The study also found that, on average, there are more emissions during the rainy season in the region than during the dry season.

ABSTRACT The Landfill Gas (LFG) generated in municipal solid waste (MSW) landfills consists of the main greenhouse gases such as methane (CH4) and carbon dioxide (CO2). Cover layer systems of sanitary landfills are designed to mitigate the LFG emission into the atmosphere and control water infiltration. Thus, this research aims to quantify and evaluate CH4 and CO2 accurate emissions in the final cover layer system at the Jockey Club Controlled Landfill in Brasília (ACJC) by using the static flux chamber. The emission results were estimated by adjusting the concentration data obtained in 12 tests in the cover layer by the methods of Linear Regression (LR) and the Non-Steady-State Diffusion Flux Estimator (NDFE). Fugitive emissions ranged from 0 to 685.6 g CH4 m-2 day-1 and 0 to 1,563.94 g CO2 m-2 day-1 using the LR method. Using the NDFE method, emissions up to 4.2 and 2.5 times greater than the LR method were estimated for CH4 and CO2, respectively. (LFG MSW (MSW CH (CH4 CO2. CO . (CO2) infiltration Thus ACJC (ACJC chamber 1 (LR NonSteadyState Non Steady State NDFE. (NDFE) 6856 685 6 685. m2 m 2 m- day1 day day- 156394 563 94 1,563.9 42 4 4. 25 5 2. respectively (CH (CO2 (NDFE 68 15639 56 9 1,563. (CO 1563 1,563 156 1,56 15 1,5 1,

RESUMO O biogás gerado em aterros de resíduos sólidos urbanos (RSU) é constituído pelos principais gases do efeito estufa, como metano (CH4) e dióxido de carbono (CO2). As camadas de cobertura de aterros sanitários são executadas para mitigar a emissão do biogás para a atmosfera e controlar a infiltração de água. Assim, esta pesquisa visou quantificar e avaliar as emissões pontuais de CH4 e CO2 na camada de cobertura definitiva no antigo Aterro Controlado Jóquei Clube de Brasília (ACJC), utilizando a placa de fluxo estática. Os resultados de emissão foram estimados ajustando os dados de concentração obtidos em 12 ensaios na cobertura pelos métodos da regressão linear (RL) e o non steady state diffusion flux estimator (NDFE). As emissões fugitivas variaram de 0 a 685,6 gCH4 m-2 dia-1 e de 0 a 1563,94 gCO2 m-2 dia-1 utilizando-se o método RL. Por meio do método NDFE, estimaram-se emissões até 4,2 e 2,5 vezes maiores do que pelo o método RL para CH4 e CO2, respectivamente. RSU (RSU estufa CH (CH4 CO2. CO . (CO2) água Assim ACJC, ACJC , (ACJC) estática 1 (RL NDFE. NDFE (NDFE) 6856 685 6 685, gCH m2 m 2 m- dia1 dia dia- 156394 1563 94 1563,9 gCO utilizandose se estimaramse estimaram 42 4 4, 25 5 2, respectivamente (CH (CO2 (ACJC (NDFE 68 15639 156 9 1563, (CO 15

Resumo O aquecimento global é atribuído ao aumento das emissões de gases de efeito estufa (GEE), como dióxido de carbono (CO2), metano (CH4) e óxido nitroso (N2O). As mudanças no uso da terra têm impactos significativos nas emissões de GEE, sendo responsáveis por aproximadamente 44% das emissões do país em 2019. Essa é uma revisão que aborda as principais rotas de formação dos GEE no solo com foco na influência das mudanças do uso da terra nas emissões de GEE. Constata-se que as emissões de CO2 pelo solo estão relacionadas à respiração de raízes, microrganismos e decomposição da matéria orgânica (MO) do solo, assim mudanças no uso da terra podem alterar as características do solo, favorecendo a intensificação das emissões de CO2. As emissões de CH4 pelo solo ocorrem em condições de anaerobiose por microrganismos metanogênicos, no entanto as mudanças no uso da terra, como a conversão de florestas em pastagens, podem aumentar as emissões de CH4 devido a uma maior concentração de microrganismos metanogênicos no solo. Já o N2O é produzido no solo durante o processo de nitrificação e desnitrificação por microrganismos, e a fertilização nitrogenada em áreas agrícolas pode aumentar as emissões de N2O, especialmente quando associada à umidade e disponibilidade de carbono orgânico no solo. Destaca-se a importância de compreender as dinâmicas de formação e emissão de GEE decorrentes das mudanças de uso da terra, pois estratégias eficientes de manejo podem reduzir essas emissões e contribuir para o cumprimento das metas do Brasil em relação à redução de GEE estabelecidas em acordos internacionais. , (GEE) CO2, CO (CO2) CH (CH4 N2O. NO . N (N2O) 44 2019 Constatase Constata se raízes MO (MO pastagens Destacase Destaca internacionais (GEE (CO2 (CH (N2O 4 201 (CO 20 2

Abstract Global warming is attributed to the increase in greenhouse gas (GHG) emissions, such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). Land use changes significantly impact on GHG emissions, accounting for approximately 44% of the country’s emissions in 2019. This review addresses the main pathways of GHG formation in the soil, focusing on the influence of land use changes on GHG emissions. It is found that soil CO2 emissions are related to root respiration, microorganisms, and organic matter (OM) decomposition in the soil. Changes in land use can alter soil characteristics, favoring increased CO2 emissions. Soil CH4 emissions occur under anaerobic conditions by methanogenic microorganisms; however, land use changes, such as forest conversion to pasture, can increase CH4 emissions due to a higher concentration of methanogenic microorganisms in the soil. On the other hand, N2O is produced in the soil during nitrification and denitrification processes by microorganisms, and nitrogen fertilization in agricultural areas can increase N2O emissions, especially when associated with soil moisture and the availability of organic carbon. It is important to understand the dynamics of GHG formation and emissions resulting from land use changes because efficient management strategies can reduce these emissions and contribute to Brazil’s goals for GHG reduction as established in international agreements. (GHG CO2, CO , (CO2) CH4, CH (CH4) N2O. NO . N O (N2O) 44 countrys country s 2019 respiration OM (OM characteristics however pasture hand Brazils Brazil agreements (CO2 (CH4 (N2O 4 201 (CO (CH 20 2

Resumen: El relleno sanitario abandonado en la ciudad de Veracruz, ubicado al norte del municipio, fue construido en el año 2000. Operó, para un tiempo de vida útil de 10 años, de acuerdo a la normatividad vigente en la época. Sin embargo, continuó su operación de manera irregular, colapsando y convirtiéndose en un sitio de disposición final controlado que fue clausurado por las autoridades ambientales estatales en el año 2019. Mediante el uso de imágenes satelitales de Google Earth y el uso de técnicas multicriterio se determinó que cuenta con una superficie de 167 228 m² y un volumen acumulado de residuos de 1 505 052 m³. Se utilizó el Modelo Mexicano de Biogás 2.0 para estimar la generación de Biogás, que hasta el año 2023 fue de un total de 2 898 064 toneladas de Biogás. Con la ayuda de la metodología para el cálculo de efecto invernadero por residuos sólidos urbanos se determinó que en este mismo período se emitieron un total de 2 522 057.3 toneladas de dióxido de carbono, 1 162 154.8 toneladas de metano y 47 115.9 toneladas de óxido nitroso, lo que representa un total de 47.5 Mt CO2eq. Lo dicho evidencia la importancia de minimizar las emisiones de gases de efecto invernadero, así como su impacto al ambiente por el calentamiento global de la atmósfera, sobre todo en el ecosistema costero en el que se asienta el municipio de Veracruz, México.

Abstract: The Abandoned Sanitary Landfill of the City of Veracruz, located to the north of the municipality, was built in the year 2000 and operated according to the regulations in force at the time, for a useful life of 10 years. However, it continued its operation irregularly, collapsing and becoming a controlled final disposal site that was closed by the state environmental authorities in 2019. Through the use of Google Earth satellite images using multicriteria techniques, it was determined that it has an area of 167 228 m² and an accumulated volume of waste of 1 505 052 m³, The Mexican Biogas Model 2.0 was used to estimate the generation of biogas that until the year 2023 was a total of 2 898 064 tons of biogas and with the help of the methodology for the greenhouse effect calculation for urban solid waste. It was determined that in this same period a total of 2 522 057.3 tons of carbon dioxide, 1 162 154.8 tons of methane and 47 115.9 tons of nitrous oxide were emitted. Which represents a total of 47.5 Mt CO2eq, which shows the importance of minimizing greenhouse gas emissions and their impact on the environment due to global warming of the atmosphere, especially in the coastal ecosystem where the municipality of Veracruz, Mexico is located.

Resumen Introducción. Los sistemas ganaderos del piedemonte amazónico se caracterizan por una baja eficiencia en el uso del suelo, predominio de monocultivos de gramíneas y disminución significativa de la cobertura arbórea, que sumado a la contribución de gases de efecto invernadero, relacionan la actividad ganadera con el calentamiento global. Objetivo. Recopilar y analizar resultados de investigaciones sobre las especies Erythrina poeppigiana (Walp.) O.F. Cook, Clitoria fairchildiana R.A. Howard, Piptocoma discolor (Kunth) Pruski y Guazuma ulmifolia Lam. Desarrollo. Mediante el uso de Google Scholar, fórmulas de búsqueda y términos claves asociados al objetivo del estudio, se recuperaron y analizaron 97 documentos. Para las especies de interés, se reportó un amplio rango de adaptación ambiental (0 - 1600 m s. n. m. y entre 1000 y 3700 mm precipitación/año), con potencial para desarrollarse en suelos mal drenados y con bajo pH. Su uso se asoció a cercas vivas, bancos forrajeros, consumo en pastoreo, entre otros. Asimismo, se reportaron valores de materia seca entre 23 y 35 %, proteína cruda entre 15 y 21 % y FDN y FDA <60 % y <45 %, respectivamente. También se encontraron reportes de metabolitos secundarios como taninos y saponinas, lo que podría relacionarse con un potencial para mitigar metano entérico. Se analiza la inclusión de estas especies de plantas forrajeras o similares, por tener un impacto positivo en el almacenamiento de carbono y restauración de áreas degradadas, dadas sus implicaciones en el suelo como fijación de nitrógeno (leguminosas) y aporte de nutrientes vía hojarasca. Conclusiones. Por sus características nutricionales, adaptación y perfil fitoquímico, sería pertinente evaluar el comportamiento de las especies E. poeppigiana, C. fairchildiana, P. discolor y G. ulmifolia, como estrategia para mejorar la oferta nutricional y disminuir las emisiones de metano entérico en condiciones de piedemonte amazónico.

Abstract Introduction. The Amazon foothills livestock is characterized by inefficient land use, pasture monoculture, and significant reduction of the forest, which added to greenhouse gas emissions; it correlates the livestock practices to climate change. Objective. To compile and analyze research on Erythrina poeppigiana (Walp.) O.F. Cook, Clitoria fairchildiana R.A. Howard, Piptocoma discolor (Kunth) Pruski and Guazuma ulmifolia Lam. Development. Through the use of Google Scholar, search algorithms, and keywords 97 papers related to this study were found and analyzed. To the forage shrubs of interest, the review reported a wide environmental range of adaptation (0 - 1600 m a. s. l. and between 1000 and 3700 mm rain/year), with the potential to develop in poorly drained soils and with low pH. The use of these shrubs in livestock was related to living fences, fodder banks, and direct intake, among others. Likewise, the literature review reported a dry matter concentration between 23 and 35 %, crude protein between 15 % and 21 %, and NDF and ADF <60 % and <45 %, respectively. Additionally, reports of secondary plant metabolites like tannins and saponins were also found, which could be related to the reduction of enteric methane. Lastly, the review examines the potential effect on carbon storage and land restoration by including the shrubs species discussed in the present study due to the possible effect on nitrogen fixation (legumes) and soil nutrient restoration via litter decomposition. Conclusions. Due to their nutritional characteristics, wide range of adaptation, and phytochemical profile, it would be pertinent to evaluate the behavior of the species E. poeppigiana, C. fairchildiana, P. discolor, and G. ulmifolia, as a strategy to improve nutrition and reduce methane emission in the Amazon foothills livestock farming.

Resumen Introducción. La lechería especializada del trópico alto colombiano presenta elevados costos de producción, emisiones de metano y contaminación por nitrógeno en el suelo y agua, empleo de plaguicidas en las praderas y una producción de leche que aún no alcanza altos estándares de calidad. Lo anterior, requiere un cambio estructural en el modelo de producción con un enfoque de sustentabilidad. Además de otros aspectos, la ganadería sostenible requiere mayor complementariedad y diversidad de especies forrajeras, arbustivas y arbóreas adaptadas a las condiciones de trópico de altura. Objetivo. Recopilar información a través de acción participativa y de innovación rural por los productores y avances de investigación de las especies Axonopus catarinensis y Smallanthus sonchifolius, forrajeras herbáceas con posible potencial productivo y ambiental (en etapa preliminar), para su integración en sistemas silvopastoriles del trópico alto colombiano. Desarrollo. A. catarinensis y S. sonchifolius son especies que podrían ser utilizadas en la alimentación básica y suplementación energética, respectivamente, de vacas lecheras en el trópico alto colombiano. Aunque no existe información científica para estas condiciones, la referencia de algunos productores menciona que estas especies tal vez pueden mejorar la producción y la calidad de la leche con efectos en la economía familiar. Además, pueden contribuir a la generación de productos lácteos con atributos funcionales benéficos, que impacten en la salud humana. Conclusión. A. catarinensis y S. sonchifolius son especies que pueden tener un potencial forrajero y nutricional para incluirse en los sistemas silvopastoriles de producción lechera en el trópico alto colombiano.

Abstract Introduction. Specialized dairy farming in Colombia highlands entails high production costs, methane emissions, nitrogen pollution in soil and water, the use of pesticides in pastures, and milk production that has not yet reached high-quality standards. All of these factors necessitate a structural change in the production model with a sustainability focus. In addition to other aspects, sustainable livestock farming requires greater complementarity and diversity of forage, shrub, and tree species adapted to high-altitude tropical conditions. Objective. To gather information through participatory action and rural innovation by producers and research advancements on the species Axonopus catarinensis and Smallanthus sonchifolius, herbaceous forage species with potential production and environmental benefits (in preliminary stage), for their integration into silvopastoral systems in the Colombian highlands. Development. A. catarinensis and S. sonchifolius are species that could be used in basic diet and energy supplementation, respectively, of dairy cows in the Colombian highlands. While there is no scientific information available for these conditions, some producers' experiences suggest that these species may improve milk production and quality with positive effects on family economics. Additionally, they can contribute to the generation of dairy products with beneficial functional attributes that impact human health. Conclusion. A. catarinensis and S. sonchifolius are species that may have forage and nutritional potential to be included in silvopastoral dairy production systems in the Colombian highlands.

Resumen Introducción. Los forrajes en el trópico presentan una baja digestibilidad, por lo que se buscan alternativas alimenticias como la Tithonia diversifolia (Hemsl.) para aumentar la calidad de la dieta ofrecida. Objetivo. Evaluar el efecto del tipo de fertilizante y la edad de rebrote del forraje de Tithonia diversifolia sobre los parámetros ruminales. Materiales y métodos. El trabajo se realizó en el año 2020 en la Finca Experimental Santa Lucía de la Universidad Nacional, Costa Rica. Se utilizó un diseño de parcelas divididas completamente al azar con el tipo de fertilizante como parcela principal y edad de rebrote como subparcela, con tres repeticiones por tratamiento. Los tipos de fertilizante fueron: lombricompost (L), químico (Q) y control (C) sin fertilizante. Las edades de rebrote evaluadas fueron 30, 50 y 70 días para un total de nueve tratamientos. Las variables evaluadas fueron: cinética de degradabilidad in situ de la materia seca (DISMS), pH, nitrógeno amoniacal (NH3), producción de gas y metano in vitro (CH4). Se realizó un ANDEVA para parcelas divididas. Resultados. La mayor DISMS se encontró en C30 (92,84 %) y menor en Q70 (64,21 %). El tipo de fertilización influyó sobre los contenidos de NH3, el mayor valor se presentó en los tratamientos con fertilización química (275,88 mg NH3/L fluido ruminal). C70 produjo la mayor cantidad de gas (79,59 mL/g), en contraste con Q30 que fue el de menor promedio (28,38 mL/g). La producción de CH4 no mostró diferencias significativas, con valores entre 3,42 y 8,67 mL CH4/g MS. Conclusión. La fertilización y edad de rebrote modificaron los parámetros ruminales in situ e in vitro. Los resultados obtenidos permiten considerar este recurso forrajero como un complemento de las gramíneas de pastoreo en el trópico, donde se generen efectos positivos sobre la digestibilidad de la MS, la producción de gas y de CH4.

Abstract Introduction. Forages in the tropics have low digestibility, which is why alternative feed option such as Tithonia diversifolia (Hemsl.) are sought to improve the quality of the offered diet. Objective. To evaluate the effect of fertilizer type and the regrowth age of Tithonia diversifolia forage on rumimal parameters. Materials and methods. The study was conducted in 2020 at the Santa Lucía Experimental Farm of the Universidad Nacional, Costa Rica. A completely randomized split-plot design was used with fertilizer type as the main plot and regrowth age as subplot, with three replications per treatment. The fertilizer types were: vermicompost (L), chemical (Q), and control (C) without fertilizer use. The evaluated regrowth ages were 30, 50, and 70 days, resulting in a total of nine treatments. The variables assessed were: in situ dry matter degradability kinetics (DISMS), pH, ammoniacal nitrogen (NH3), in vitro gas, and methane production (CH4). An ANOVA was carried out for divided plots. Results. The highest DISMS was found in C30 (92.84 %) and the lowest in Q70 (64.21 %). The type of fertilization influenced NH3 contents, with the highest value observed in chemical fertilizer treatments (275.88 mg NH3/L rumen fluid). C70 produced the highest amount of gas (79.59 mL/g), whereas Q30 had the lowest average (28.38 mL/g). Methane production did not show significant differences, with values ranging from 3.42 to 8.67 mL CH4/g DM. Conclusion. Fertilization and regrowth age modified in situ and in vitro ruminal parameters. The obtained results suggest that this forage resource can be considered a supplement to grazing grasses in the tropics, where positive effects are generated on DM digestibility, gas, and CH4 production.