ABSTRACT Biochar can promote crop production and soil quality. However, its characteristics depend on the waste used in its production and its effects may vary according to the species being cultivated and the management adopted. The aim of this study was to evaluate the application of biochar from animal waste on soil quality and the agronomic characteristics of the cowpea. An experiment was set up to test three types of biochar (bovine-BB, swine-SB and poultry-BP), with added fertiliser (BBF, SBF and BPF) and two control treatments, including the addition of calcium magnesium oxide (CT) and calcium magnesium oxide with fertiliser (CTF), giving a total of eight treatments with four replications. There was a respective increase of up to 102.94%, 1048%, 1560% and 360.22% in stem diameter, number of pods, number of grains per pod and stem dry matter from adding the biochar. The poultry biochar increased each of the above parameters even with no added fertiliser. There was no difference in basal soil respiration or β-glucosidase enzyme activity, whereas organic carbon (TOC), total nitrogen (TN), microbial carbon and soil labile carbon were greater with biochar. BBF gave the highest TOC content (24.40 g kg-1), while BP and BPF increased TN by around 61%. The application of biochar + fertiliser contributed to an average reduction of 56% in the soil metabolic quotient. Poultry biochar favoured both the agronomic characteristics of the cowpea and soil quality, while bovine biochar showed more marked results with the addition of fertiliser. However adopted bovineBB, bovineBB BB, BB (bovine-BB swineSB swine SB poultryBP, poultryBP , poultry-BP) BBF, (BBF CT (CT CTF, CTF (CTF) replications 10294 102 94 102.94% 1048 1048% 1560 36022 360 22 360.22 diameter pods βglucosidase β glucosidase activity TOC, (TOC) TN, (TN) 24.40 2440 24 40 (24.4 kg1, kg1 kg 1 kg-1) 61 61% 56 quotient poultry-BP (CTF 1029 10 9 102.94 104 156 3602 36 2 360.2 (TOC (TN 24.4 244 4 (24. kg-1 6 5 102.9 15 3 360. 24. (24 kg- 102. (2 (

RESUMO: A batata-doce é uma cultura importante para a segurança alimentar com mercado mundial em ascensão. Com base nas alterações fisiológicas das plantas em resposta às condições climáticas e à fertilização, este estudo avaliou os efeitos da época de cultivo (período chuvoso e seco) e de doses de P2O5 (0, 50, 100, 200 e 400 kg ha-1) na produtividade total e por classes comerciais, bem como, a composição química das raízes de armazenamento de duas cultivares de batata-doce. A produtividade de raízes tuberosas foi maior na estação chuvosa. As doses ótimas agronômica e econômica foram de 128 e 95 kg ha-1 de P2O5 para a cultivar Canadense. A cultivar Uruguaiana não respondeu a adubação fosfatada, mas suas raízes tiveram maiores teores de matéria seca, lipídios, fibras, açúcares totais e redutores e amido. O cultivo de batata-doce no período chuvoso com doses de até 100 kg ha-1 de P2O5 aumenta a produtividade de raízes em classes de maior valor econômico e com maiores teores de carboidratos. Estes resultados ajudam os produtores a planejarem o plantio e a colheita da batata-doce ao longo do ano e contribui para a gestão da aplicação de fertilizantes fosfatados. RESUMO batatadoce batata doce ascensão fertilização seco PO P P2O 0, 0 (0 50 20 40 ha1 ha 1 comerciais como batatadoce. doce. chuvosa 12 9 ha- Canadense fosfatada seca lipídios fibras amido 10 carboidratos fosfatados ( 5 2 4

ABSTRACT: Sweet potato is an important food security crop, and the world market for this root is on the rise. Based on the physiological changes in plants in response to climatic conditions and fertilization, this study evaluated the effects of the growing season (rainy and dry season) and P2O5 doses (0, 50, 100, 200 and 400 kg ha-1) on total yield, marketable classes yields, as well as chemical composition of storage roots of two sweet potato cultivars. The storage roots yield was greater in the rainy season. The optimum agronomic and economic doses were 128 and 95 kg ha-1 P2O5 for the cultivar Canadense. Cultivar Uruguaiana did not respond to phosphate fertilization, but its storage roots had higher contents of dry matter, lipids, fibers, total and reducing sugars, and starch. Sweet potato cultivation in the rainy season with doses up to 100 kg ha-1 P2O5 increase root yield in marketable size classes in higher economic value and with higher carbohydrate contents. The results can help producers schedule the planting and harvesting of sweet potatoes throughout the year and contribute to the seasonal management of phosphate fertilizer application. ABSTRACT crop rise fertilization PO P O P2O 0, 0 (0 50 20 40 ha1 ha 1 yields cultivars 12 9 ha- Canadense matter lipids fibers sugars starch 10 application ( 5 2 4

RESUMO: A fisiologia das plantas muda ao longo do dia porque os fotoassimilados podem aumentar a concentração de carboidratos solúveis em água à tarde em comparação com a manhã. Este estudo teve como objetivo avaliar o efeito do horário de colheita na composição morfológica da silagem de milho de planta inteira, tamanho de partícula, perfil de fermentação, composição química, degradação in vitro e estimativa da produção de leite. Um ensaio agronômico de dois anos foi realizado em delineamento inteiramente casualizado, e um silo experimental foi produzido por cada parcela (n = 16). A colheita da tarde aumentou (P < 0,01) o teor de matéria seca em relação à colheita da manhã. A época de colheita não afetou (P ≥ 0,32) a proporção de grãos, colmos e folhas do milho e o tamanho das partículas da silagem. Entretanto, a colheita da manhã aumentou (P = 0,01) a recuperação de matéria seca e não teve efeito (P ≥ 0,10) no pH da silagem e nas concentrações de ácido láctico e acético em comparação à colheita da tarde. Além disso, a colheita da tarde, em vez da colheita da manhã, aumentou (P ≤ 0,05) o amido da silagem, os carboidratos solúveis em água, a lignina detergente ácida e o teor de extrato etéreo e a degradação in vitro da matéria seca. Controversamente, os tratamentos não mostraram efeito (P ≥ 0,14) na concentração de energia da silagem, no conteúdo energético estimado e na produção de leite. Assim, a colheita da manhã produz mais matéria seca da silagem, mas a colheita da tarde melhora o valor nutricional da silagem de milho sem impacto na produção estimada de leite. RESUMO inteira partícula fermentação química leite casualizado n 16. 16 . 16) P 0,01 001 0 01 0,32 032 32 grãos Entretanto 0,10 010 10 disso 0,05 005 05 Controversamente 0,14 014 14 Assim 1 0,0 00 0,3 03 3 0,1 0,

ABSTRACT: Plants’ physiology changes through the day because photoassimilates can increase water-soluble carbohydrate concentration in the afternoon compared to the morning. This study evaluated the harvest time effect on whole-plant corn silage morphological composition, particle size, fermentation profile, chemical composition, in vitro degradation, and estimated milk yield. A two-year agronomic assay was performed in a completely random design, and one experimental silo was produced by each parcel (n = 16). The afternoon harvest increased (P < 0.01) dry matter content compared to the morning harvest. Harvest time did not affect (P ≥ 0.32) corn grain, stalk, leaf proportion, and silage particle size. However, the morning harvest increased dry matter recovery (P = 0.01) and had no effect (P ≥ 0.10) on silage pH and concentrations of lactic and acetic acid compared to the afternoon harvest. In addition, afternoon harvest instead of morning harvest increased (P ≤ 0.05) silage starch, water-soluble carbohydrates, acid detergent lignin, and ether extract content and dry matter in vitro degradation. Controversially, treatments showed no effect (P ≥ 0.14) on silage energy concentration, estimated energy content, and milk yield. Thus, the morning harvest produces more silage dry matter, but the afternoon harvest improves corn silage’s nutritional value with no impact on estimated milk yield. ABSTRACT Plants watersoluble water soluble wholeplant whole plant composition size profile degradation yield twoyear two year design n 16. 16 . 16) P 0.01 001 0 01 0.32 032 32 grain stalk proportion However 0.10 010 10 addition 0.05 005 05 starch carbohydrates lignin Controversially 0.14 014 14 Thus silages s 1 0.0 00 0.3 03 3 0.1 0.

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: 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 (

Abstract Introduction. There is a great human concern about antibiotics resistance due to their inappropriate use as growth promoters in animal husbandry. Objective. To evaluate the effect of a high level of zinc as a substitute to antibiotics in nursery pigs. Material and methods. The study was carried out from June to August 2022 in the province of Chiriqui, Panama. The experimental period was composed of three phases with 14 days per phase. The nursery pigs (n= 54) were distributed to one of three treatments with six replicates per treatment and three pigs per replicate. The treatments were: 1) control diet, which was formulated to meet the nutritional requirements for nursery pigs; 2) similar to treatment 1, plus 200 mg of amoxicillin/kg of feed and 40 mg of florfenicol/kg of feed during phase 1 (P1) and phase 2 (P2), respectively; and 3) similar to treatment 1, plus 2000 ppm and 1600 ppm of zinc during P1 and P2, respectively. In phase 3 (P3), all pigs were fed a common diet. Results. The supplementation of zinc improved the average daily gain in all phases. Pigs fed zinc diet had better F:G ratio in P2 compared to pigs fed antibiotic diet (p < 0.05). A higher concentration of hemoglobin and percentage of monocytes was found in pigs fed with higher level of zinc than the other treatments (p < 0.05). Furthermore, Pigs fed the antibiotic, or the control diet had a lower percentage of fecal dry matter compared to those supplemented with zinc. (p < 0.05). Conclusion. The supplementation of high levels of zinc exerted improvements, in comparison to the antibiotic, in terms of hemoglobin concentration, incidence of diarrhea and weight gain in pigs during 42 days after weaning.

Resumen Introducción. Existe una gran preocupación humana por la resistencia a los antibióticos debido a su uso inadecuado como promotores del crecimiento en la cría de animales. Objetivo. Evaluar el efecto de altos niveles de zinc como sustituto del antibiótico en lechones destetados. Material y métodos. El estudio se realizó de junio a agosto de 2022 en la provincia de Chiriquí, Panamá. El periodo experimental estuvo compuesto por tres fases con 14 días por fase. Los cerdos destetados (n= 54) fueron asignados a uno de tres tratamientos con seis repeticiones por tratamiento y tres cerdos por repetición. Los tratamientos fueron: 1) dieta control, formulada para suplir los requerimientos nutricionales para cerdos destetados; 2) similar al tratamiento 1, más 200 mg de amoxicilina/kg de alimento y 40 mg de florfenicol/kg de alimento durante la fase 1 (P1) y fase 2 (P2), respectivamente; y 3) similar al tratamiento 1, más 2000 ppm y 1600 ppm de zinc durante P1 y P2, respectivamente. En la fase 3 (P3), todos los cerdos fueron alimentados con una dieta común. Resultados. La suplementación con zinc mejoró la ganancia de peso en todas las fases. Los cerdos alimentados con zinc tuvieron mejor relación F:G en P2 en comparación a los cerdos suplementados con antibiótico (p < 0.05). Se encontró una mayor concentración de hemoglobina y porcentaje de monocitos en cerdos alimentados con zinc que en los otros tratamientos (p < 0.05). Los cerdos alimentados con antibiótico o la dieta control tuvieron un menor porcentaje de materia seca fecal en comparación a los suplementados con zinc (p < 0.05). Conclusión. La suplementación de altos niveles de zinc ejerció mejoras, en comparación al antibiótico, en cuanto a la concentración de hemoglobina, incidencia de diarrea y ganancia de peso en cerdos durante los 42 días posteriores al destete.

Abstract Introduction. The soil and climatic conditions of Ecuador are ideal for rice cultivation, yields are higher than the world average, but agronomic management leads to an increase of cadmium in the soil, which can reach the grain by translocation, which affects its safety. Objetive. To evaluate the absorption of cadmium through the omission of macronutrients technique in six soils of Ecuador and its effect on the vegetative development of rice crops. Materials and methods. The trial was carried out at the Pichilingue Tropical Experimental Station of the National Institute of Agricultural Research, Ecuador, during 2018. Nine treatments were studied: 1) Without fertilization and without Cd (control 1), 2) without fertilization and with Cd (Control 2), 3) Complete fertilization and six omission treatments of one nutrient at a time, a completely randomized block design of experiments, divided plots and three repetitions was used. The variables evaluated were those related to the production of dry matter in the root and aerial part. For the comparison between means, the Tukey test was used (p<0.05). Results. Nutrients omissions (N and P) led to reduced Cd absorption, which decreased dry matter production, particularly in very acidic or alkaline soils such as in Sucumbíos (pH 4) and Guayas (pH 7, 9), respectively. Conclusions. The absorption of cadmium in rice plants was reduced to a greater extent with the omission of the macronutrients N and P, mainly in the soils of Sucumbíos, Los Ríos, El Oro and Manabí, the nutrient omission technique also affecting the production of dry matter and yields, also observing that a pH below 5 or higher than 7.9 affects the absorption of cadmium in the soils studied.

Resumen Introducción. Las condiciones edafoclimáticas del Ecuador son ideales para el cultivo del arroz, los rendimientos son mayores al promedio mundial, pero su manejo agronómico conlleva a un aumento de cadmio en el suelo, que puede llegar al grano por translocación, lo cual afectan su inocuidad. Objetivo. Evaluar la absorción de cadmio mediante la técnica de omisión de macronutrientes en seis suelos del Ecuador y su efecto sobre el desarrollo vegetativo del cultivo de arroz. Materiales y métodos. El ensayo se realizó en la Estación Experimental Tropical Pichilingue del Instituto Nacional de Investigaciones Agropecuarias, Ecuador, durante el año 2018. Se estudiaron nueve tratamientos 1) Sin fertilización y sin Cd (testigo 1), 2) sin fertilización y con Cd (Testigo 2), 3) Fertilización completa y seis tratamientos de omisión de un nutriente a la vez, se usó un diseño de experimentos de bloques completamente al azar, parcelas divididas y tres repeticiones. Las variables evaluadas fueron las relacionadas a la producción de materia seca en raíz y parte aérea. Para la comparación entre medias, se utilizó la prueba de Tukey (p<0,05). Resultados. Las omisiones de los nutrientes (N y P) llevaron a la reducción de la absorción del Cd, que disminuyó la producción de materia seca, en particular en los suelos muy ácidos o alcalinos como en Sucumbíos (pH 4) y Guayas (pH 7,9), respectivamente. Conclusiones. La absorción de cadmio en plantas de arroz se redujo en mayor medida con la omisión de los macronutrientes N y P, principalmente en los suelos de Sucumbíos, Los Ríos, El Oro y Manabí, afectando también la omisión de nutrientes a la producción de materia seca y los rendimientos, observándose además que un pH por debajo de 5 o superior a 7,9 afecta la absorción de cadmio en los suelos estudiados

Abstract Introduction. The cultivation of dragon fruit (Hylocereus costaricensis and H. monocanthus) is increasing in Costa Rica, but technical information for its management, such as nutritional requirements, fertilization timing, and growth behavior, is lacking. Objective. To quantify and model the growth and nutrient uptake of dragon fruit (H. costaricensis and H. monocanthus) under dry tropics conditions in Costa Rica. Materials and methods. The research was conducted from 2017 to 2020 in Guanacaste, Costa Rica. Plants were sampled at 76, 165, 308, 450, 607, 903, 1249, and 1706 days after planting (DAP) and 205 fruits were analyzed. Dry matter was quantified, and the uptake of N, P, Ca, Mg, K, S, Fe, Cu, Zn, Mn, and B was calculated. Two logistic models were fitted to determine nutrient uptake, and linear regressions were calibrated for fresh fruit. Results. For a planting density of 3000 plants/ha, the nutritional requirements per hectare were: 137 kg N, 32 kg P, 327 kg K, 63 kg Mg, 32 kg S, 1,60 kg Zn, and 0,21 kg B. The best-fitting logistic model (RMSE = 0.09) accurately estimated the uptake of N, P, Ca, S, Zn, and B. The linear regression model demonstrated high predictive capacity (R2 > 0.85) for the nutrient requirements of N, P, K, Mg, and S in the fruit. Conclusion. Logistic models provided high precision in deterministically modeling nutrient uptake in dragon fruit plants. The study affectively quantified and modeled the nutritional behavior of the plants under Costa Rica’s dry tropical conditions, providing essential information for optimizing fertilization programs for the crop.

Resumen Introducción. El cultivo de pitahaya (Hylocereus costaricensis y H. monocanthus) está en aumento en Costa Rica, pero carece de información técnica para su manejo, como necesidades nutricionales, momentos de fertilización y comportamiento del crecimiento. Objetivo. Cuantificar y modelar el crecimiento y la absorción de nutrimentos del cultivo de pitahaya (H. costaricensis y H. monocanthus) en condiciones del trópico estacional seco de Costa Rica. Materiales y métodos. La investigación se realizó durante los años 2017-2020, en Guanacaste, Costa Rica. Se muestrearon plantas a los 76, 165, 308, 450, 607, 903, 1249 y 1706 días después de siembra (DDS) y 205 frutas. Se cuantificó la materia seca y se calculó la absorción de N, P, Ca, Mg, K, S, Fe, Cu, Zn, Mn y B. Se ajustaron dos modelos logísticos para determinar la absorción de nutrientes y se calibraron regresiones lineales en fruta fresca. Resultados. Para una densidad de siembra de 3000 planta/ha los requerimientos nutricionales del cultivo por hectárea fueron: 137 kg N, 32 kg P, 327 kg K, 63 kg Mg, 32 kg S, 1,60 kg Zn y 0,21 kg B. El modelo logístico de mejor ajuste (RMSE = 0,09) estimó de forma precisa la absorción de N, P, Ca, S, Zn y B. El modelo de regresión lineal tuvo alta capacidad predictora (R2 > 0,85) para los requerimientos de N, P, K, Mg y S en fruta. Conclusión. Los modelos logísticos tuvieron alta precisión para modelar de manera determinística la absorción de nutrientes en plantas de pitahaya. Además, se logró cuantificar y modelar de forma eficiente el comportamiento nutricional de las plantas en condiciones de trópico estacional seco de Costa Rica, lo que proporciona información esencial para los programas de fertilización del cultivo.

Resumen El sistema de producción bovino de doble propósito es el más predominante en el trópico, caracterizado por un sistema de pastoreo extensivo de gramíneas nativas o introducidas con baja digestibilidad y altas concentraciones de carbohidratos estructurales, provocando con esto una baja eficiencia productiva de los sistemas, ante este escenario, es necesario buscar alternativas que mejoren la eficiencia productiva. El objetivo fue evaluar la fermentación anaeróbica y digestibilidad ruminal in vitro de la materia seca (DIVMS) de los ensilados de S. bicolor y C. cajan. En los tratamientos se utilizaron cuatro sustratos (sorgo, sorgo + C. cajan, C. cajan, sorgo + C. cajan + inoculante) y cuatro tiempos de fermentación anaeróbica (0, 30, 60 y 90 días), en un diseño completamente al azar con un arreglo factorial 4x4, con tres repeticiones. El promedio de MS, MO, PC, FDN y FDA fue 373.9±41.43; 960.58±7.59; 87.82±24.95; 588.73±51.17; 371.76±61.39 g kg-1 de MS. Para la DIVMS fue de 56.32±9.05%. Se encontró diferencias significativas (P<0.05) para los parámetros de fermentación y DIVMS. El volumen máximo de gas se presentó en los tratamientos que contenían únicamente sorgo y sorgo + C. cajan + inoculante. Las fracciones de rápida fermentación fueron mayores (P<0.05) en los tratamientos sorgo + C. cajan + inoculante. Las fracciones de fermentación media y lenta fueron mayores en sorgo y sorgo + C. cajan + inoculante. Se concluye que la planta de C. cajan sola o combinada presenta un efecto negativo en la DIVMS.

ABSTRACT The dual-purpose cattle production system is the most predominant in the tropics, characterized by an extensive grazing system of native or introduced grasses with low digestibility and high concentrations of structural carbohydrates, causing with this a low productive efficiency of the systems, in this scenario, it is necessary to look for alternatives that improve productive efficiency. The objective was to evaluate the anaerobic fermentation and rumen digestibility in vitro of dry matter (DIVDM) of silages of S. bicolor and C. cajan. Four substrates (sorghum, sorghum + C. cajan, sorghum + C. cajan + inoculant) and four anaerobic fermentation times (0, 30, 60 and 90 days) were used in the treatments, in a completely randomized design with a 4x4 factorial arrangement, with three replications. The average for DM, OM, CP, NDF and ADF was 373.9±41.43; 960.58±7.59; 87.82±24.95; 588.73±51.17; 371.76±61.39 g kg-1 DM. For DIVDM it was 56.32±9.05 %. Significant differences (P<0.05) were found for fermentation parameters and DIVDM. The maximum volume of gas was presented in treatments containing only sorghum and sorghum + C. cajan + inoculant. The fractions of rapid fermentation were higher (P<0.05) in the treatments sorghum + C. cajan + inoculant. The fractions of medium and slow fermentation were higher in sorghum and sorghum + C. cajan + inoculant. It is concluded that the C. cajan plant alone or combined has a negative effect on DIVDM.

Summary: The middle area of the state of Sinaloa in Northwestern Mexico is characterized by a warm semi-arid climate where rainfall is insufficient for the adequate development of some introduced plant species. For example, those that correspond to the genus Brachiaria, despite technological advances in sencor development, the producers have limted access to sufficient meteorological information. Therefore, the aim in the present study is to determine water requirement, crop coefficient, and productivity of Convert 300 hybrid grass (Brachiaria sp) in a warm semiarid climate of Mexico by using the Food and Agriculture Organization (FAO56 Penman-Montiel equation) method with complete and limited data; a meteorological station was used to measure climatic parameters, and the FAO56 method with dual kc was applied to estimate crop evapotranspiration under non-standard conditions, and subsequently, water productiviy. The estimated water consumption for the Convert 330 hybrid in the warm semiarid climate of northwest Mexico was 1849 mm with measured data and 1973.5 mm with limited data. The statistical analyses yielded a coefficient of determination (R2) of 0.92, Willmott’s coefficient of agreement (d) of 0.90, RMSE of 0.694 mm d-1, BIAS of 0.380 mm d-1 and a Nash-Sutcliffe coefficient of efficiency (EF) of 0.98. The kc values were 0.49, 1.11 and 1.04 for initial, middle and end of season, respectively; the water productivity (WUE) was 2.666 kg m-3 for green forage, and 0.726 kg m-3, for dry matter, in the same way, 375.1 and 1378 L kg-1 were required to produce green forage and dry matter, respectively. To conclude, althought the ETc estimation with limited data overestimated the ETc with measured data by 6.7%, statistics showed that the procedure is reliable.

Resumen: La región central del estado de Sinaloa en el noroeste mexicano, se caracteriza por un clima semiárido cálido donde la precipitación es insuficiente para el desarrollo adecuado de algunas especies vegetales introducidas, como las correspondientes al género Brachiaria, a pesar del avance tecnológico en el desarrollo de sensores, es escaso el acceso de los productores a suficiente información meteorológica; el objetivo del presente trabajo consistió en determinar el requerimiento hídrico, coeficiente de cultivo y productividad del pasto híbrido Convert 330 (Brachiaria sp) en un clima semiárido cálido de México, utilizando el método FAO56 con datos medidos y datos limitados; se utilizó una estación meteorológica para medir los parámetros climáticos, y se aplicó el método FAO56 con kc dual para estimar la evapotranspiración de cultivo bajo condiciones no estándar, y posteriormente, la productividad del agua. El consumo de agua estimado para el pasto Convert 330 en clima semiárido cálido del noroeste de México fue de 1849 mm con datos medidos y 1973.5 mm con datos limitados; el análisis estadístico arrojó un coeficiente de determinación (R2) de 0.92, coeficiente de concordancia de Willmott (d) de 0.90, RMSE de 0.694 mm d-1, BIAS=0.380 mm d-1 y un coeficiente de eficiencia de Nash-Sutcliffe (EF) de 0.98. Los valores de kc obtenidos fueron de 0.49, 1.11 y 1.04 paras las etapas inicial, media y final, respectivamente; la productividad del agua (EUA) fue de 2.666 kg m-3 para forraje verde y 0.726 kg m-3 para materia seca; asimismo, se requirieron 375.1 y 1378 L kg-1 para la producción de forraje verde y materia seca, respectivamente. Finalmente, se concluye que, aunque la estimación de la ETc con datos limitados sobrestimó en un 6.7% la ETc con datos medidos, la estadística muestra que es confiable el procedimiento.

Summary: Avocado is a fruit (Persea americana), that has increased its consumption worldwide. Mexico is the main producer and exporter of avocado in the world, representing more than 30% of the world harvest, of which 73.2% of the total avocado production in Mexico was concentrated in the state of Michoacán. In the state of Michoacán, there is a constant production of avocado fruit throughout the year, but this production is affected by the variation in climate, water management and flowering type, putting agricultural production and sustainable development at risk. The objective of this study was to evaluate the climatic effect, water management, and flowering type on fruit nutrient content in six orchards in the state of Michoacan. Six orchards were evaluated in the towns of Basilia, Cheranguerán, Tecario, Araparicuaro, Peribán and Patamburu in the state of Michoacan, which represent 90% of the climate types (TC), predominant in the state (ACW1, ACW2 and CW1)., with 100% of the water regime (irrigated and seasonal, RH) and 97% of the type of fruit produced (loca and normal, FF). The dry matter contents and total mineral content of the fruit were evaluated. The arrangement of treatments was a factorial [A= water regime (RH); B= type of climate (TC); C= floral flow (FF)], distributed completely randomly with 20 repetitions taking each tree as a repetition. The results indicated that the dry matter content is affected by TC, but not by RH and FF, FF affects the nutritional content more than TC and RH. The type of climate is the factor with the least impact on the mineral content of the fruit. In floral flow, the total nutritional content was significant in four elements with higher values for N, Cl, and Zn in crazy fruit and Na in normal fruit.

Resumen: El aguacate (Persea americana), es un fruto que ha incrementado su consumo a nivel mundial. México es el principal productor y exportador de aguacate en el mundo que representa más del 30% de la cosecha mundial, del cual el 73.2% de la producción total de aguacate en México se concentra en el estado de Michoacán, pero dicha producción es afectada por la variación del clima, poniendo en peligro la producción agrícola y el desarrollo sostenible. El objetivo del fue evaluar el efecto climático, manejo de agua y el tipo de floración sobre el contenido nutrimental del fruto en seis huertas del estado de Michoacán. Se evaluaron seis huertos de las localidades de la Basilia, Cheranguerán, Tecario, Araparicuaro, Peribán y Patamburu del estado de Michoacan, que representan un 90% de los tipos de clima (TC), predominantes en el estado (ACW1, ACW2 y CW2), con un 100% del régimen de agua (riego y temporal, RH) y un 97% del tipo de fruto producido (loca y normal, FF). Se evaluaron los contenidos de materia seca y el contenido mineral total del fruto. El arreglo de tratamientos fue una factorial [A= régimen hídrico (RH); B= tipo de clima (TC); C= flujo floral (FF)], distribuido completamente al azar con 20 repeticiones tomando cada árbol como una repetición. Los resultados indicaron que el contenido de materia seca es afectado por TC, pero no por RH y FF, FF afecta más el contenido nutricional que TC y RH. El tipo de clima es el factor de menor impacto en el contenido mineral del fruto. En flujo floral el contenido nutricional total fue significativo en cuatro elementos con mayor valor para N, Cl, y Zn en fruto loca y Na en fruto normal.

Abstract Introduction: Methanogenic archaea (MA), participate in the anaerobic mineralization of organic matter in mangrove sediments, their activity is related to atmospheric warming due to the production of methane; several environmental variables can influence the presence of MA and methane production in these sediments. Objective: To analyze, through culture-dependent techniques, viable methanogenic archaea (VMA) in the sediments, and the production of methane from acetate in different climatic periods in the mangrove El Morro-La Mancha, Veracruz, Gulf of Mexico. Methods: From May to November 2019, following a salinity transect, sediment samples from El Morro-La Mancha mangrove were collected at three locations, in three different climatic seasons, dry (May), rainy (October) and northern (November) (N = 9). VMA in the sediments was quantified using the Most Probable Number (MPN) technique with acetate and methanol as substrates. The influence of sulfate on methane production was analyzed from acetate in microcosm by gas chromatography and the chemical variables of salinity, pH, Eh, carbohydrates, organic content, and carbonates in the sediments were evaluated. Results: The abundance of VMA was 102 to 108 MPN/g of wet sediment, higher than that reported in other studies, this abundance was higher when methanol (104-108 MPN/g sediment) was used as substrate, compared to acetate (102-105 MPN/g sediment); methane production in the microcosms increased in sulfate-free conditions (29.78-929.75 nmol CH4/month) and in the sediments of the rainy season. Conclusion: The influence of the chemical conditions of the mangrove sediments on the methanogenic dynamics is highlighted, determining that in the rainy season, the decrease in salinity, more electronegative Eh, and the increase in organic fractions favored the methanogenesis.

Resumen Introducción: Las arqueas metanogénicas (MA) participan en la mineralización anaerobia de la materia orgánica en sedimentos de manglar, su actividad está relacionada con el calentamiento atmosférico por la producción de metano; diversas variables ambientales pueden influir en la dinámica metanogénica y la producción de metano en estos sedimentos. Objetivo: Analizar, mediante técnicas dependientes de cultivo, la abundancia de las arqueas metanógenas viables (AMV) y la producción de metano en diferentes épocas climáticas en los sedimentos del manglar El Morro-La Mancha, Veracruz, Golfo de México. Métodos: De mayo a noviembre 2019, siguiendo un transecto de salinidad, se recolectaron sedimentos del manglar del Morro-La Mancha, en tres localidades, abarcando tres diferentes épocas climáticas, secas (mayo), lluvias (octubre) y nortes (noviembre) (N = 9), cuantificándose la abundancia de las AMV mediante la técnica del Número Más Probable (NMP) con acetato y metanol como substratos; la influencia de los sulfatos en la producción de metano a partir de acetato en microcosmos, se analizó por cromatografía de gases y se evaluaron las variables químicas de salinidad, pH, Eh, carbohidratos, contenido orgánico y carbonatos en los sedimentos. Resultados: Se determinó una abundancia de AMV de 102 a 108 NMP/g de sedimento húmedo, superior a la reportada en otros estudios, dicha abundancia se incrementó cuando se utilizó metanol (104-108 NMP/g sedimento) como sustrato, en comparación con el acetato (102-105 NMP/g sedimento); la producción de metano en los microcosmos aumentó en condiciones libres de sulfatos (29.78-929.75 nmol CH4/mes) y en los sedimentos de la temporada de lluvias. Conclusión: Se destaca la influencia de las condiciones químicas de los sedimentos del manglar sobre la dinámica metanógena, determinándose que, en la temporada de lluvias, una disminución de la salinidad, Eh más electronegativos y el incremento de las fracciones orgánicas favorecieron la metanogénesis.

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.

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 Background: Maize landraces show remarkable diversity and environmental adaptability in Mexico. Nevertheless, few studies have explored physiological mechanisms used by different maize landraces to grow and yield in a particular agroecological region. Question: How do three landrace maize populations from contrasting maize races in southeastern Mexico, differ in their responses in terms of growth, chlorophyll fluorescence, and gas exchange? Studied species: Zea mays L. Study site and date: Yucatan, Mexico; 2017. Methods: The field experiment followed a complete randomized block design, with six replicates. Three contrasting maize landraces were evaluated as treatments. Response variables were vegetative traits, dry matter allocation, yield components, and maize physiological responses. Data were analyzed by one-way ANOVA and post hoc Tukey multiple comparison test (P ≤ 0.05). Results: Maize landraces showed differences in cycle length, plant morphology, and yield performance. The long cycle maize landrace Xnuc-naal, had tall plants that accumulated 17 and 21 % more dry matter than Xmejen-naal and Elotillo, respectively. The short-cycle maize landraces Elotillo and Xmejen-naal exhibit superior physiological responses leading to higher grain yields compared to the Xnuc-naal. Conclusions: The landrace Xnuc-naal stood out for its ability in forage production, whereas Elotillo and Xmejen-naal exhibited notable physiological efficiency in grain production in southeastern Mexico.

Resumen Antecedentes: Las razas nativas de maíz muestran una notable diversidad y adaptabilidad en México. Sin embargo, pocos estudios han explorado los mecanismos fisiológicos utilizados por las diferentes razas de maíz para crecer y producir en una región agroecológica en particular. Pregunta: ¿Cómo difieren en sus respuestas en cuanto a crecimiento, fluorescencia de la clorofila e intercambio de gases tres variedades de maíz que provienen de razas contrastantes del sureste de México? Especie estudiada: Zea mays L. Sitio y fecha del estudio: Yucatán, México; 2017. Métodos: El experimento de campo siguió un diseño de bloques completamente aleatorios, con seis repeticiones. Se evaluaron tres variedades nativas de maíz contrastantes como tratamientos. Las variables de respuesta fueron rasgos vegetativos, distribución de materia seca, componentes del rendimiento y respuestas fisiológicas de las variedades de maíz. Los datos fueron analizados mediante ANOVA de una vía y la prueba de comparación múltiple de Tukey (P ≤ 0.05). Resultados: Las variedades locales de maíz mostraron diferencias en la duración del ciclo, morfología de la planta y rendimiento. La variedad tardía Xnuc-naal, tuvo plantas altas que acumularon un 17 y 21 % más materia seca que Xmejen-naal y Elotillo, respectivamente. Las variedades precoces Elotillo y Xmejen-naal exhibieron una respuesta fisiológica superior que llevó a un rendimiento de grano superior al de Xnuc-naal. Conclusiones: La variedad de maíz Xnuc-naal destacó por su capacidad para la producción de forraje, mientras que Elotillo y Xmejen-naal demostraron una eficiencia fisiológica notable en la producción de grano en el sureste de México.

ABSTRACT This research aimed to assess the impact of applying mountain microorganisms (MM) on coffee seedling production. Two nurseries (A and B) were used with weekly and bi-weekly treatment applications. Plant height, leaf and root lengths, and dry matter content (DM) were measured. Results showed that Nursery A, with weekly treatments, exhibited greater height and leaf length growth compared to Nursery B. In the initial measurement, Nursery A accumulated more leaf DM than Nursery B. However, over time, both nurseries experienced a decline in DM. Root length variability was observed in both nurseries throughout the measurements. Treatments with MM from forest and coffee systems in Nursery A showed higher leaf DM accumulation in the initial measurement. In conclusion, MM application, especially with higher frequency, promoted coffee seedling growth. The results emphasize the need for detailed analysis to understand optimal root development conditions. The decline in DM over time is a natural response to active growth, indicating increased nutritional requirements. These findings support MM-based strategies for sustainable coffee seedling production.

RESUMEN La investigación tuvo como objetivo evaluar el efecto de la aplicación de microorganismos de montaña (MM) en la producción de plántulas de café. Se utilizaron dos viveros (A y B) con aplicaciones de tratamientos semanales y quincenales. Se midió la altura de las plantas, la longitud de las hojas y raíces, así como el contenido de materia seca (MS). Los resultados mostraron que el Vivero A, con tratamientos semanales, tuvo un mayor crecimiento en altura y longitud de hojas en comparación con el Vivero B. En la primera medición, el Vivero A acumuló más MS foliar que el Vivero B. Sin embargo, a medida que avanzaba el tiempo, ambos viveros experimentaron una disminución en el MS. En la longitud de las raíces, se observó variabilidad en ambos viveros a lo largo de las mediciones. Los tratamientos con MM de bosque y café en el Vivero A mostraron una mayor acumulación de MS foliar en la primera medición. En conclusión, la aplicación de MM, especialmente con mayor frecuencia, promovió el crecimiento de las plántulas de café. Los resultados muestran la necesidad de análisis detallados para comprender las condiciones óptimas para el desarrollo de raíces. La disminución del MS con el tiempo es una respuesta natural al crecimiento activo y por tanto el aumento del requerimiento nutricional de las plántulas. Estos resultados respaldan estrategias basadas en MM para una producción sostenible de plántulas de café.

ABSTRACT Residues generated in sugarcane production such as biochar, originated from bagasse burning, are used as a fertilizer source, which can increase forage dry matter yield, as well as improving soil chemical attributes. The objective of this study was to evaluate the effects of using biochar from sugarcane bagasse burning and mineral fertilization, as well as their association, on the dry matter yield of Urochloa decumbens and on the chemical attributes of the soil. The design was randomized blocks, which consisted of eight treatments and four blocks. The treatments were: T1- mineral fertilization; T2- fertilization with limestone plus mineral fertilizer; T3- liming; T4- biochar; T5- biochar plus mineral fertilizer; T6- liming plus biochar; T7- double fertilization with biochar and T8- control. Association of mineral fertilizer and biochar was able to increase dry matter yield by up to 131% when compared to the control treatment during the first year. The use of fertilization strategies in the restoration of degraded area under U. decumbens does not interfere with soil chemical attributes, except for sulfur. source association blocks were T1 T T2 T3 T4 T5 T6 T7 T8 131 year U sulfur 13 1

RESUMO Resíduos gerados pela produção de cana-de-açúcar como o biochar, proveniente da queima do bagaço podem ser utilizados como fonte de fertilizante, podendo incrementar a produção de matéria seca de forrageira, bem como, dos atributos químicos do solo. O objetivo deste trabalho foi avaliar a utilização de biochar da queima do bagaço da cana-de-açúcar e da adubação mineral e associação de ambos, na produtividade de matéria seca de Urochloa decumbens, e nos atributos químicos do solo. O delineamento utilizado foi em blocos casualizados, composto por oito tratamentos, com quatro repetições. Os tratamentos foram: T1- adubação mineral; T2- adubação com calcário + fertilizante mineral; T3- calagem; T4- biochar; T5- biochar + adubação mineral; T6- calagem + biochar; T7- duas vezes a dose com biochar e T8- controle. A associação de fertilizante mineral com biochar foi capaz de aumentar a produção de matéria seca em até 131% quando comparado ao tratamento controle no primeiro ano. O emprego de diferentes estratégias de fertilização na recuperação de área degradada sob uso de Urochloa decumbens, não interfere nos atributos químicos do solo, com exceção do elemento enxofre. canadeaçúcar cana açúcar forrageira solo ambos decumbens casualizados repetições foram T1 T T2 T3 T4 T5 T6 T7 T8 131 ano enxofre 13 1