14 research outputs found

    Herbage Allowance and Nitrogen Fertilization Effects on Morphological Characteristics of \u3ci\u3ePaspalum notatum\u3c/i\u3e Flügge

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    The grazing study was conducted at the Estação Experimental Agronomica – UFRGS, 30o S, on a native pasture, to evaluate the leaf area index and structural morphological traits of bahiagrass (Paspalum notatum Fl.), within the requirements of a Central Composite Rotatable experimental design, providing for equal precision, with two blocks, encompassing two factors at five levels each, namely: Herbage Allowance (HA) = 4.0; 5.5; 9.0; 12.5 and 14.0 kg green dry matter per 100 kg liveweight per day (% LW), in association with Nitrogen (N) fertilization levels of 0; 30; 100; 170 and 200 kg ha-1 as urea, The leaf length and leaf area index (LAI) were increased as HA and N levels increased. The tiller density was increased at higher HA where the N contribution showed to be more effective. More lenient grazing also increased leaf life span and leaf lamina length, while N promoted canopy density and reduced leaf life span and number of leaves per tiller. The higher LAI values developed were accomplished by reduced tiller densities that supported small number of leaves per tiller, with increased leaf sizes

    Ecosystem and productive benefits of the strategic inclusion of annual legumes into an annual ryegrass pasture in a no-tillage integrated crop-livestock system

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    Annual winter pastures are strategic components in crop-livestock systems in Uruguay. The aim of this study was to evaluate the N legume fixation into an annual ryegrass pasture contrasted to the N fertilizer addition. The experimental design was a randomized complete block design with 2x2 factorial arrangement of the treatments, two pasture types: a) annual ryegrass (Lolium multiflorum L.) pasture, and b) of annual ryegrass with two annual legume species (Trifolium resupinatum L. and Trifolium vesiculosum L.); and two levels of N fertilizer: a) no N fertilizer, and b) 64 kg N ha-1. They were grazed with Holstein steers. Setaria italica crop was planted in summer to evaluate the carry over effects of the treatments on its herbage mass production. Pasture accumulated herbage mass was significantly increased with N fertilizer (P ≤ 0.01), increment of 1277 ± 322.5 kg DM ha-1. The legume species’ addition plus N fertilization led to a higher nitrogen nutrition index in the mixed pastures. Ryegrass herbage mass was positively influenced by N addition, but with that there was a 47% of weed herbage mass increase in the pure annual ryegrass pastures. The average daily gain of steers was positively influenced by legumes, with an average of 1.01 kg PV day-1 in mixtures. N fertilizer addition allowed a higher stocking rate and higher animal production in winter. A carryover effect of the treatments was not found on S. italica accumulated herbage mass. Legumes’ addition to annual ryegrass allowed a greater animal performance but did not provide any additional benefit to the following summer crop.Las pasturas anuales de invierno son componentes estratégicos de los sistemas agropecuarios en Uruguay. El objetivo de este estudio fue evaluar el efecto de la fijación biológica de N de leguminosas en una mezcla con raigrás anual en contraste con la adición de fertilizante nitrogenado. El diseño experimental fue un diseño de bloques completos al azar con arreglo factorial 2 x 2 de los tratamientos, con dos tipos de pasturas: a) pastura de raigrás anual (Lolium multiflorum L.), y b) pastura mezcla de raigrás anual con dos especies de leguminosas anuales (Trifolium resupinatum L. y Trifolium vesiculosum L.); y dos niveles de fertilización con N: a) sin fertilizante, y b) 64 kg N ha-1. Las pasturas fueron pastoreadas con novillos Holstein. En verano se realizó un cultivo de Setaria italica para evaluar los efectos de los tratamientos en la producción de biomasa de este. La biomasa acumulada de las pasturas de invierno incrementó significativamente con fertilización de N (P ≤ 0.01), con un incremento de 1277 ± 322.5 kg MS ha-1. La pastura mezcla fertilizada con N produjo un mayor índice de nutrición nitrogenada que la pastura de raigrás anual. La biomasa aérea de raigrás presentó un incremento con el agregado de N; sin embargo, en las pasturas monofíticas de raigrás hubo un aumento del 47% de malezas. La ganancia media diaria de los novillos incrementó con la incorporación de leguminosas, con un promedio en las pasturas mezclas de 1,01 kg PV día-1. La adición de fertilizante nitrogenado permitió una mayor carga animal y una mayor producción animal en invierno. No se encontró un efecto de los tratamientos en la biomasa acumulada de S. italica. La incorporación de leguminosas al raigrás anual permitió una mayor ganancia diaria de peso vivo por animal, pero no produjo un efecto adicional sobre el cultivo sucesor de verano.Gerencia de Comunicación Institucional, DG SICyP, INTAFil: García Favre, Javier. Universidad de la República. Estación Experimental Mario A. Cassinoni (EEMAC). Departamento Producción Animal y Pasturas; UruguayFil: García Favre, Javier. Massey University. School of Agriculture and Environment; Nueva ZelandaFil: Zanoniani, Ramiro A. Universidad de la República. Estación Experimental Mario A. Cassinoni (EEMAC). Departamento Producción Animal y Pasturas; UruguayFil: Lopez, Ignacio F. Massey University. School of Agriculture and Environment; Nueva ZelandaFil: Cadenazzi, Mónica. Universidad de la República. Estación Experimental Mario A. Cassinoni (EEMAC). Departamento Biometría, Estadística y Computación; UruguayFil: Sacido, Mónica Benita. Universidad Nacional de Rosario. Facultad de Agronomía; ArgentinaFil: Mailhos, M.E. Universidad de la República. Estación Experimental Mario A. Cassinoni (EEMAC). Departamento Producción Animal y Pasturas; UruguayFil: Boggiano, Pablo. Universidad de la República. Estación Experimental Mario A. Cassinoni (EEMAC). Departamento Producción Animal y Pasturas; Urugua

    Caracterização de méis de diferentes regiões do Uruguai, marcadores de origem

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    Uruguay produces and exports honey. Honey is appreciated worldwide and has been well studied in terms of its chemical composition. These studies help determine botanical origin and prevent fraud. However, Uruguay exports honey without differentiating; the diversity of soils and vegetation in the country allows different types of honey production. Therefore, the aim of this work was to characterize honey from four regions of the country including three protected areas. The samples were collected during one year in two stations and electrical conductivity, humidity, sugar profile, macrominerals (K, Ca, Na and Mg) and pollen content were analyzed. The quality of the studied environments was evaluated by determining the presence of glyphosate. Results from this study confirm significant differences among the analyzed honeys from the different regions (Tukey-Kramer, p 0.8 mS / cm) associated with high mineral content were found. 37 different pollen taxa (family, genus or species) were detected. Some samples are monofloral (main pollen> 45%) of cultivated species (Lotus sp and Trifolium repens) or native species (Parkinsonia aculeata, Lithraea brasiliensis, Myrcianthes sp and Tripodanthus acutifolius). Calcium and sodium are suggested as markers of geographic origin. Mannose is suggested as a marker of botanical origin. The detection of glyphosate appears associated with agricultural activities even in protected areas. Uruguay produces different honeys that can be marketed indicating origin. More regions should be studied and for longer periods.Uruguay produce y exporta miel, alimento mundialmente apreciado y estudiado en términos de su composición química. Estos estudios ayudan a determinar el origen geográfico y botánico y a prevenir fraudes. Sin embargo, Uruguay exporta miel sin diferenciar. La diversidad de suelos y vegetación del país permite diferentes tipos de producción de miel. El objetivo de este trabajo fue caracterizar la miel de cuatro regiones del país, de las que tres son áreas protegidas. Las muestras se recolectaron durante un año en dos estaciones. Se analizó conductividad eléctrica, humedad, perfil de azúcar, macrominerales (K, Ca, Na y Mg) y contenido de polen. Se evaluó la calidad de los ambientes estudiados determinando la presencia de glifosato. Se encontraron diferencias entre las mieles analizadas (Tukey-Kramer, p 0.8 mS / cm) asociadas a altos contenidos minerales. Se detectaron 37 taxas de pólenes diferentes (familia, género o especie). Algunas muestras son monoflorales (polen principal> 45%) de especies cultivadas (Lotus sp y Trifolium repens) o especies nativas (Parkinsonia aculeata, Lithraea brasiliensis, Myrcianthes sp y Tripodanthus acutifolius). Se sugieren calcio y sodio como marcadores de origen geográfico. Se sugiere la manosa como marcador de origen botánico. La detección de glifosato aparece asociada con las actividades agrícolas incluso en áreas protegidas. Uruguay produce diferentes mieles que se pueden comercializar indicando origen, se deberían estudiar más regiones y durante más tiempo.O Uruguai produz e exporta mel. Um alimento apreciado em todo o mundo e estudado quanto à sua composição química. Esses estudos ajudam a determinar a origem geográfica e botânica e a prevenir fraudes. No entanto, o Uruguai exporta mel sem se diferenciar. A diversidade de solos e vegetação do país permite diferentes tipos de produção de mel. O objetivo deste trabalho foi caracterizar mel de quatro regiões do país. Três são áreas protegidas. As amostras foram coletadas durante um ano em duas estações. Condutividade elétrica, umidade, perfil de açúcar, macrominerais (K, Ca, Na e Mg) e conteúdo de pólen foram analisados. A qualidade dos ambientes estudados foi avaliada pela determinação da presença de glifosato. Foram encontradas diferenças entre os méis analisados ​​(Tukey-Kramer, p 0,8 mS / cm) associadas a alto teor de minerais foram encontradas. 37 taxa de pólen diferentes (família, gênero ou espécie) foram detectados. Algumas amostras são monoflorais (pólen principal> 45%) de espécies cultivadas (Lotus sp e Trifolium repens) ou espécies nativas, Parkinsonia aculeata, Lithraea brasiliensis, Myrcianthes sp e Tripodanthus acutifolius). O cálcio e o sódio são sugeridos como marcadores de origem geográfica. A manose é sugerida como um marcador de origem botânica. A detecção do glifosato aparece associada às atividades agrícolas mesmo em áreas protegidas. O Uruguai produz diferentes méis que podem ser comercializados com indicação de origem. Mais regiões devem ser estudadas e por mais tempo

    Teor de oligoelementos e capacidade antioxidante em méis de regiões fitogeográficas protegidas do Uruguai

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    Honey is a natural sweet substance produced by honey bees, from the nectars of plant flowers and honey dew. The components of honey vary depending on the geographical site and the existing flora. The objective of this work was to characterize Uruguayan honeys produced in different regions by composition of trace elements (Cu, Fe, Mn, Mo, Zn, I, Se), the antioxidant capacity, the total polyphenols, and the palynological profile. Sixty-six honey samples were obtained in two seasons, spring-summer and summer-autumn, from three regions of protected areas, and a fourth region associated with human activities. The results obtained show that the contents of Cu and Mn were significantly higher (P<0.05) in region C (1.785 ug/g and 4.668 ug/g). For Mo, the Q region presented 1.060 ug/g, being significantly different (P<0.05) from the other regions. The total polyphenol content from region C was significantly higher (P<0.05) (66.442 mg GAE/100g). Likewise, the antioxidant capacity presented significant differences (P<0.05) for region C in the spring-summerseason. Some species, genus or botanical families were only found in a particular region. This work allows us to affirm that honey can be differentiated by its micronutrient content associated with the total polyphenol content, and a higher antioxidant activity for certain regions, given by the floral species present in the region and the type of soil.La miel es una sustancia dulce natural producida por las abejas melíferas a partir del néctar de las flores de las plantas y de secreciones de partes vivas de estas. Los componentes de la miel varían según el sitio geográfico y la flora existente. El objetivo de este trabajo fue caracterizar las mieles uruguayas producidas en diferentes regiones por composición de oligoelementos (Cu, Fe, Mn, Mo, Zn, I, Se), capacidad antioxidante, polifenoles totales y perfil palinológico. Se obtuvieron 66 muestras de miel en dos temporadas, primavera-verano y verano-otoño, de tres regiones de áreas protegidas y una cuarta región asociada a actividades humanas. Los resultados obtenidos muestran que los contenidos de Cu y Mn fueron significativamente mayores (P<0,05) en la región C (1,785 ug/g y 4,668 ug/g). Para Mo, la región Q presentó 1,060 ug/g, siendo significativamente diferente (P<0,05) de las demás regiones. El contenido de polifenoles totales de la región C fue significativamente mayor (P<0,05) (66,442 mgGAE/100g). Asimismo, la capacidad antioxidante presentó diferencia significativa (P<0,05) para la región C en la época primavera-verano. Algunas especies, géneros o familias botánicas solo se encontraron en una región en particular. Este trabajo permite afirmar que la miel se puede diferenciar por su contenido de micronutrientes asociados al contenido de polifenoles totales y una mayor actividad antioxidante para ciertas regiones, dada por las especies florales presentes en la región y el tipo de suelo.O mel é uma substância doce natural produzida pelas abelhas a partir do néctar das flores das plantas e das secreções das partes vivas das plantas. Os componentes do mel variam de acordo com o local geográfico e a flora existente. O objetivo deste trabalho foi caracterizar méis uruguaios produzidos em diferentes regiões por composição de oligoelementos (Cu, Fe, Mn, Mo, Zn, I, Se), capacidade antioxidante, polifenóis totais e perfil palinológico. Sessenta e seis amostras de mel foram obtidas em duas estações, primavera-verão e verão-outono, de três regiões de áreas protegidas e uma quarta região associada a atividades humanas. Os resultados obtidos mostram que os teores de Cu e Mn foram significativamente maiores (P<0,05) na região C (1,785 ug/ge 4,668 ug/g). Para Mo, a região Q apresentou 1.060 ug/g, sendo significativamente diferente (P<0,05) das demais regiões. O teor total de polifenóis da região C foi significativamente maior (P<0,05) (66,442 mgGAE/100g). Da mesma forma, a capacidade antioxidante apresentou diferença significativa (P<0,05) para a região C na estação primavera-verão. Algumas espécies, gêneros ou famílias botânicas foram encontrados apenas em uma determinada região. Este trabalho permite-nos afirmar que o mel pode ser diferenciado pelo seu teor de micronutrientes associado ao teor de polifenóis totais e uma maior atividade antioxidante para determinadas regiões, dada pelas espécies floral presentes na região e pelo tipo de solo

    Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

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    The objective of this study was to evaluate the chemical composition of the forage apparently consumed by steers in a natural grassland on region of Campanha, in Rio Grande do Sul, Brazil, subjected or not to different inputs: NP - natural pasture without inputs; FNP - fertilized natural pasture and INP - improved natural grassland with fertilization and over-seeded with cultivated winter species. Three Angus steers testers and a variable number of regulator animals per experimental unit were utilized in order to maintain 13 kg of DM/100 kg of live weight (LW) as forage allowance. One time at each season, hand plucking samples were performed along the daily grazing time simulating forage harvested by the animals. The collected samples after drying and grind were submitted to chemical analysis to determine the forage quality. Except in winter and spring, the values of neutral detergent fiber were higher than the critical value of 550 g/kg of DM, which could limit forage intake, demonstrating that the values of forage on offer provided (15.6; 13.7; 13.5; 15.8 kg of DM/100 kg of LW/day in summer, autumn, winter and spring, respectively) were not restrictive to intake. The oversowing of winter cultivated species or fertilization positively alter the degradable fiber content. The seasons had marked influence on the chemical composition of forage apparently consumed; positively increasing some fractions of forage chemical composition in the seasons in which native or cultivated winter species increased their participation. The forage chemical composition is the determining factor in animal performance in natural pasture

    Dinámica de la producción espacial temporal de dos pasturas plantadas con especies perennes

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    The objective of the present work was to evaluate the forage production, botanical composition and stability of two perennial forage mixtures under grazing during a period of four years. The study was performed at EEMAC, FAGRO, UdelaR 32º23'27.1 ”south latitude and 58º03'41.76” west longitude (Paysandú, Uruguay). Two pastures were evaluated, a) Festuca arundinacea (festuca), Trifolium repens (clover) and Lotus corniculatus (lotus), (FBL) b) Dactylis glomerata (dactylis) and Medicago sativa (alfalfa), (DA). The experimental design was randomized complete blocks with four replications. The total forage production of both pastures did not differ statistically, although it did present a different seasonal distribution in the first two years. The DA mix reached higher spring/summer/autumn productions (P &lt;0.05); while in FBL the lowest productions of the sown species were in the summer/autumn period. Both mixtures showed great resilience capacity in the winter/spring period given that each year they recovered their biomass contribution to about 90% of the total. Festuca arundinacea was the species with the highest persistence of the sown crops, achieving a 60% contribution in the fourth year; while Medicago sativa was the most stable legume. Summer annual C4 grasses were the main constituent species of summer weed, providing biomass in the period of least productivity of the FBL mixture. It is concluded that it is possible to achieve high forage productions for 4 years and that the use of both mixtures would improve the seasonal distribution of production systems.El objetivo del presente trabajo fue evaluar la producción de forraje, composición botánica y estabilidad de dos mezclas forrajeras perennes bajo pastoreo durante un período de cuatro años. El estudio se realizó en Paysandú, Uruguay, 32º23'27.1 ”de latitud sur y 58º03'41.76” de longitud oeste. Se evaluaron dos mezclas forrajeras, a) Festuca arundinacea (festuca) cv Tacuabe, Trifolium repens (trébol) cv Zapicán y Lotus corniculatus (lotus) cv San Gabriel, (FBL) b) Dactylis glomerata (dactylis) cv INIA Perseo y Medicago sativa ( alfalfa) cv Chaná, (DA). El diseño experimental fue en bloques completos al azar con cuatro repeticiones. La producción total de forraje de ambas mezclas forrajeras no se diferenció, aunque se detectó varias distribuciones estacionales en los dos primeros años. La mezcla DA tuvo mayores producciones en el período primavera / verano / otoño (P &lt;0.05); mientras que en FBL las menores producciones de las especies sembradas fueron en el período verano / otoño. Las mezclas combinadas una gran capacidad de resiliencia en el período inverno / primavera dado que todos los años recuperaron su contribución de biomasa a cerca del 90% del total. Festuca fue la especie que presentó mayor persistencia logrando una contribución de 60% en el cuarto año; mientras que alfalfa fue la leguminosa con mayor estabilidad. Las gramíneas C4 anuales fueron las principales especies constituyentes del enmalezamiento estival, aportando biomasa en el período de menor productividad de la mezcla FBL. Se concluye qué fue posible lograr altas producciones de forraje durante 3.5 años y la utilización de ambas mezclas permitiría mejorar la distribución estacional de forraje en los sistemas de producción

    Grazing management in an integrated crop-livestock system: soybean development and grain yield

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    ABSTRACTGrazing livestock in integrated crop-livestock systems can cause impacts in the subsequent crop cycle. Aiming to investigate how grazing could affect soybean, the 9th crop cycle of a pasture/soybean rotation was assessed. Treatments were grazing intensities (10, 20, 30 and 40 cm of sward height) applied since 2001 in a mixed of oat and annual ryegrass; and an additional no grazing area as control. Treatments were arranged in a completely randomized block design with three replicates. Grazing affected soybean population and the mass of individual nodules (P0.05). Soybean yield showed differences among treatments, but no difference was found between grazed and non-grazed areas. Grazing intensities impact the coverage and frequency of weeds (P>0.05). In conclusion, grazing intensity impacts different parameters of soybean yield and development, but only the grazing intensity of 10 cm can jeopardize the succeeding soybean crop

    Spider assemblages associated with different crop stages of irrigated rice agroecosystems from eastern Uruguay

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    The rice crop and associated ecosystems constitute a rich mosaic of habitats that preserve a rich biological diversity. Spiders are an abundant and successful group of natural predators that are considered efficient in the biocontrol of the major insect pests in agroecosystems. Spider diversity in different stages of the rice crop growth from eastern Uruguay was analysed. Field study was developed on six rice farms with rotation system with pasture, installed during intercropping stage as cover crop. Six rice crops distributed in three locations were sampled with pitfall and entomological vaccum suction machine. Sixteen families, representing six guilds, were collected. Lycosidae, Linyphiidae, Anyphaenidae and Tetragnathidae were the most abundant families (26%, 25%, 20% and 12%, respectively) and comprised more than 80% of total abundance. Other hunters (29%), sheet web weavers (25%) and ground hunters (24%) were the most abundant guilds. Species composition along different crop stages was significantly different according to the ANOSIM test. The results showed higher spider abundance and diversity along the crop and intercrop stages. This study represents the first contribution to the knowledge of spider diversity associated with rice agroecosystem in the country

    Steers production in integrated crop-livestock systems: pasture management under different sward heights

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    ABSTRACT The aim of this study was to evaluate the effects of different grazing intensities on forage production and animal performance of yearling steers kept under permanent grazing in an integrated crop-livestock system. The treatments consisted of areas with sward heights of 10; 20; 30 and 40 cm, and one treatment with no grazing. The pastures were of bristle oat (Avena strigosa Schreb.) and annual ryegrass (Lolium multiflorum Lam.) following soybean (Glycine max (L.) Merr.). The variables forage mass, forage allowance and residual straw showed a positive and linear fit to the increasing sward height (P≤0.0001). Average daily gain of steers displayed a quadratic response (P = 0.0017), being optimal with increases in grazing height up to values of near 30 cm, showing a weight gain per animal of approximately 1.0 kg day-1. A similar response was seen for live weight at slaughter and carcass characteristics (P≤0.0305). The results suggest that sward heights close to 30 cm provide greater individual gains, due to the increase in forage available to each animal and the better quality of the consumed forage without compromising the residual straw destined for the following crop

    Elaboración de pan multigrano con harinas precocidas por extrusión

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    The effect in bread quality of a new bread making process and two replacement levels (20%, 36%) of refined wheat flour by extrusion precooked prepared based on combination of oats, soybeans and wheat bran was studied. Composite flour was characterized according to its functional properties (water absorption index), grain size and nutritional properties (protein, total fiber, soluble fiber, ash, fat). The volume, whiteness index, rheological measurements (hardness, cohesiveness, springiness and chewiness) of the bread were monitored. No significant changes were recorded in hardness, elasticity and chewiness of bread according to the level of substitution of composite flour; bread with 36% substitution was 7% less cohesive, with 27% less volume bread with 20% substitution. The process conditions caused greatest impact on the quality of bread. The new process resulted in a 37% increase in volume, 6% elasticity, 15% of cohesiveness and 44% decrease in hardness and 34% in chewiness, compared to the traditional process. This trend continued in the four days following the date of processing. The substitution level of composite flour did not cause significant changes in hardness, elasticity and chewiness of bread, but changes were observed in cohesiveness and volume. Bread with 36% substitution was 7% less cohesive, with 27% less volume than the 20% substitution.Se estudió el efecto en la calidad del pan según el proceso de elaboración y del nivel de sustitución (20%, 36%) de una harina precocida por extrusión preparada en base a combinación de avena, soja y salvado de trigo en la calidad del pan. Se caracterizó la harina compuesta según sus propiedades funcionales (Índice de Absorción de Agua), granulometría y propiedades nutricionales (proteína, fibra total, fibra soluble, cenizas, materia grasa). Se realizó seguimiento del volumen, índice de blancura, medidas reológicas (dureza, cohesividad, elasticidad y masticabilidad) de los panes. Las condiciones del proceso de elaboración fue lo que generó mayor impacto en la calidad del pan. Los cambios operativos realizados provocaron un incremento del 37% en el volumen, 6% de elasticidad y 15% de cohesividad, y una disminución del 44% de dureza y 34% de masticabilidad. Esta tendencia se mantuvo en los cuatro días siguientes al día de elaboración. El nivel de sustitución de harina compuesta no provocó cambios significativos en la dureza, elasticidad y masticabilidad del pan, pero se observaron cambios en la cohesividad y volumen. El pan con 36% de sustitución resultó un 7% menos cohesivo y con un 27% menos de volumen que el de 20% de sustitución
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