The objective of this research was to evaluate of three pasture-based systems (PS) with bermuda grass (BG) + forage peanut + 75Kg de N/ha; BG + common vetch + 75Kg of N/ha and BG + 150Kg de N/ha. BG was planted in 2006. The forage peanut was planted in September in BG stand with three seedlings/m²; common vetch was over seeding in BG, in respective PS. Lactating Holstein cows receiving 1% of body weight/day complementary concentrate feed, were used for evaluation. The experiment was carried out from May 2010 to May 2011. In the pre grazing cycle the forage mass (PFM) botanical and structural composition, daily dry matter accumulation rate (DMA) and stocking rate (SR) were evaluated. The experimental design used was completely randomized were performed, with three treatment (PS), two replicates (paddocks) in completely, split-plot time. Eleven grazing cycles were performed during the experimental period (360 days). To determine crude protein (CP), neutral detergent fiber (NDF), dry matter in situ digestibility (DMISD), organic matter in situ digestibility (OMISD) and total digestible nutrients (TDN) samples were collected by the hand-plucking method. The mean values of PFM, DMA, SR, were 2.5; 2.6 and 2.5 t/ha; 58; 65 and 62 Kg of DM/ha/day; 6.0; 7.6 and 6.9 animal units/ha/day for respective PS. The mean values of CP, NDF, DMISD, OMISD and TDN were; 16.4; 22.2 and 15.3%; 68.3; 65.7 and 66.3%; 68.5; 70.3 and 66.4%; 64.3; 63.2 3and 65.1%; 57.7; 58.2 and 57.8% for respective PS. Residual effects of forage legume (common vetch) were observed on DMA and bermuda grass leaf blade percentage. Similar result for PFM and SR were found between BG + common vetch + 75 kg of N/ha and BG + 150 kg of N/ha. Towards the nutritive value the PS mixed to Coastcross-1 plus common vetch showed a better performance. / O objetivo desta pesquisa foi avaliar três sistemas forrageiros (SF), constituídos por capim bermuda (CB) + amendoim forrageiro + 75 kg de N/ha; CB + ervilhaca + 75 Kg de N/ha e CB + 150 Kg de N/ha. O CB foi estabelecido em 2006. O amendoim forrageiro foi plantado, em setembro, na área já estabelecida com CB, com três mudas/m². A ervilhaca foi sobressemeáda, em maio, na área do CB, nos respectivos SF. Para avaliação foram usadas vacas da raça Holandesa em lactação que receberam concentrado à razão de 1% do peso corporal/dia. O experimento foi conduzido entre maio de 2010 e maio de 2011. Avaliou-se a massa de forragem de pré pastejo (MFP), as composições botânica e estrutural, a taxa de acúmulo diário de matéria seca (TAC) e a taxa de lotação (TL). O delineamento experimental utilizado foi o inteiramente casualizado com três tratamentos (SF), duas repetições (piquetes) em parcelas subdivididas no tempo. Para determinar o teor de proteína bruta (PB), fibra em detergente neutro (FDN), digestibilidade in situ da matéria seca (DISMS), digestibilidade in situ da matéria orgânica (DISMO) e nutrientes digestíveis totais (NDT) foram coletadas amostras de forragem pelo método de simulação de pastejo. No período experimental (360 dias), foram conduzidos 11 ciclos de pastejo. As médias para MFP, TAC e TL foram de 2,5; 2,6 e 2,5 t/ha; 58; 65 e 62 Kg de MS/ha/dia; 6,0; 7,6 e 6,9 UA/ha/dia para os respectivos SF. Os valores médios de PB, FDN, DISMS, DISMO e NDT foram de 16,4; 22,2 e 15,3%; 68,3; 65,7 e 66,3%; 68,5; 70,3 e 66,4%, 64,3; 63,2, e 65,1%; 57,7; 58,2 e 57,8%, respectivamente. Foi observado efeito residual da leguminosa forrageira (ervilhaca) na TAC da pastagem e no porcentual de lâmina foliar do capim bermuda. Resultados similares quanto a MFP e TL foram observados entre os SF constituídos por CB + ervilhaca + 75 kg de N/ha e CB + 150 Kg de N/ha. Com relação ao valor nutritivo, verificou-se melhor resultado no SF constituído de Coastcross-1 e ervilhaca.

Made available in DSpace on 2014-08-20T13:44:45Z (GMT). No. of bitstreams: 1 dissertacao_mirihan_gamarra_flores.pdf: 1359957 bytes, checksum: 3f28e5648b0d33ac021d0f2182b2161a (MD5) Previous issue date: 2010-10-17 / Dada la importancia económica y social del cultivo del haba (Vicia faba L.) en la sierra del Perú, se ha planteado como objetivo evaluar el sistema de producción de semilla de haba a través de la calidad de semillas. Se utilizaron catorce lotes de semillas de haba de diferentes clases y categorías, producidas por el INIA y agricultores y cosechadas en 2006 y 2007, además de una muestra de semillas con tegumento manchado y una muestra de semillas que se destinaron como grano para consumo. Se realizaron diferentes pruebas de vigor basados en la evaluación de plántulas. La prueba del porcentaje de emergencia de plántulas no ha diferenciado la calidad fisiológica de las semillas con referencia a tamaño de semillas, pero sí con referencia a lotes. Las pruebas que permitieron diferenciar la calidad fisiológica de semillas por tamaño de grano fueron la velocidad de emergencia y el índice de velocidad de emergencia, Las semillas de tamaño mediano, con calibre de 16 a 21semillas/onza, han demostrado una mayor velocidad de emergencia que las semillas de tamaño grande, con calibre de 12 a 15semillas/onza. El peso total de plántulas frescas ha diferenciado el vigor de los lotes de semilla de acuerdo a sus clases y categorías. La calidad de los lotes de semillas evaluadas cumple con los requisitos establecidos por las normas vigentes. Las semillas consideradas de consumo, muestran características de vigor y de crecimiento iguales a los observados en las diferentes clases y categorías de semillas evaluadas, los criterios actuales para selección de semillas deberán reconsiderarse, ya que se determinó que las semillas de tamaño grande y mediano tienen similar calidad fisiológica y no deberían ser comercializadas para consumo, considerando que el 52% de la producción total de semilleros básicos producidos por el INIA han sido destinados como grano de consumo. Los índices de rentabilidad obtenidos por los agricultores por la venta de semilla clase común, podrían ser mayores si optaran el registro de los campos semilleros para comercializar la semilla producida en la clase certificada, por lo cual se requiere mejorar el sistema de cosecha y pos cosecha, así como implementar mecanismos adecuados que faciliten el correcto registro y adecuada comercialización de la semilla de calidad, a fin de asegurar el desarrollo de la producción de haba. / Tendo em conta a importância econômica social da cultura do fava (Vicia faba L.) na serra do Perú, o presente trabalho objetivou avaliar o sistema de produção de sementes de fava pela determinação da qualidade das sementes. Foram utilizadas quatorze lotes de sementes de diferentes classes e categorias, produzidas por INIA e agricultores, nas safras 2006 e 2007, junto com uma amostra de sementes com tegumento manchado e uma amostra de grãos para consumo. Foram utilizadas vários testes de vigor baseados na avaliação das plântulas. Usando o teste de emergência de plântulas não foi possivel diferenciar a qualidade fisiológica dos lotes em relação ao tamanho das sementes. Os testes velocidade de emergencia e índice de velocidade de emergência resultaram úteis para distinguir a qualidade fisiológica das sementes por tamanho de grão. As sementes de tamanho médios, calibre de 16 21 sementes/onça, mostraram maiores velocidades de emergencia do que as sementes de tamanho grande, calibre 12-15 sementes/onça. O peso total de plántulas frescas permite diferenciar o vigor das sementes de acordo com as suas classes e categorias. A qualidade dos lotes de sementes estudados cumprem com as exigências previstas nas normas vigentes. As sementes consideradas para consumo representadas no estudo pela amostra de grãos para consumo possuem características de vigor e crescimento similares aos, observados nas diferentes classes e categorías de sementes avaliadas no estudo. Em consideração aos resultados, os atuais critérios de seleção de sementes devem ser reconsiderados, em vista que sementes de tamanho medio têm boa qualidade fisiológica e não devem ser destinados ao consumo. Aliás considerando que o 52% da produção total de sementes básicas produzidas pelo INIA no 2007 foram descartadas e destinados ao consumo. Os índices de rentabilidade obtidos pelos agricultores pela venda de sementes classe comum podem ser maiores se optarem pelo registro dos campos de produção de sementes, pelo cual, requer-se uma melhoria do sistema de colheita e pós-colheita de sementes de fava, e estabelecer mecanismos adequados para o registro e comércio de sementes de boa qualidade, para garantir o desenvolvimento da produção.

Heterosis, die Mehrleistung der Hybride über das Mittel ihrer homozygoten Eltern, ist ein viel untersuchtes genetisches Phänomen, das bis heute in seinen Ursachen und Wirkmechanismen noch nicht vollständig verstanden ist. Die klassische Untersuchung der Heterosis wird an Merkmalen der Pflanze, wie dem Biomasse- oder Korn- Ertrag und dem Tausendkorngewicht durchgeführt. In der vorliegenden Arbeit wurde studiert, ob schon auf der Ebene des Samens als genetischem Individuum Heterosis ausgeprägt wird. Ziel der Untersuchungen war, mögliche Unterschiede im reifen Samengewicht von heterozygoten und homozygoten Samen zu finden. Außerdem sollte der Einfluß von elterlicher Verwandtschaft, elterlicher Samengröße und von verschiedenen Stresssituationen auf diese Samenheterosis analysiert werden und eine mögliche Verbindung zwischen der Samenheterosis und der klassischen Heterosis untersucht werden. Darüber hinaus sollten Effekte des Inzuchtstatus der Samen auf den Samenertrag ihrer Mutterpflanze untersucht werden.In drei Versuchsjahren wurden insgesamt 17 Ackerbohnenlinien (Vicia faba L.) verschiedener Verwandtschaftsbeziehungen und Samengrößen in fünf Experimenten im Freiland, in offener und kontrollierter Bestäubungssituation, getestet. Zusätzlich wurde ein Experiment zur Verbindung zwischen Samenheterosis und klassischer Heterosis im Gewächshaus durchgeführt. Die Differenzierung zwischen fremd- und selbstbefruchteten Samen geschah entweder durch Handkreuzungen in sog. Freiland-Isolierhäusern, oder es wurden in offener Bestäubungssituation morphologische Marker zur Klassifizierung eingesetzt. Ferner wurde erprobt, inwiefern fremd- und selbstbefruchtete Samen aus offener Bestäubungssituation mittels Nah-Infrarot-Reflexions-Spektrometrie (NIRS) zu differenzieren sind. Durch Einsatz eines speziellen Kreuzungsschemas konnte die Samenheterosis beider reziproker Kreuzungsrichtungen in verschiedenen Samengenerationen geschätzt werden und eine biometrische Trennung der maternalen von den sameneigenen genetischen Effekten vorgenommen werden.Die Ergebnisse zeigen eine deutliche Überlegenheit des Samengewichtes von Hybridsamen über entsprechend vergleichbare ingezüchtete Samen; es konnte somit Heterosis für das Merkmal Samengewicht signifikant nachgewiesen werden, sie lag je nach Kreuzung zwischen 0,36% und 18,44% Mehrgewicht des Hybridsamens über dem homozygoten Elternwert. Die Untersuchung beider reziproker Kreuzungsrichtungen hat ergeben, dass das Samengewicht signifikant (P= 0,01) beeinflusst war durch maternal additive und zytoplasmatische Effekte, sowie durch sameneigene Dominanz- und Additiveffekte. Direkte Konkurrenz um mütterliche Ressourcen führte zu keiner Erhöhung der Hybridüberlegenheit, ebenso konnte keine höhere Überlegenheit der Hybridsamengewichte über die der Selbstungssamen nachgewiesen werden, wenn die Pflanze unter abiotischem Stress (Trockenheit) wuchs. Es wurde deutlich höhere Heterosis gefunden, wenn der Vergleich zwischen den Samengenerationen auf einem hohen Niveau der Samengröße stattfand, als wenn es sich um kleine Samen handelte. Die Ergebnisse zeigen tendenziell eine Erhöhung der Samenheterosis, wenn Heterozygotie für die elterliche Samengröße vorliegt, während keinerlei Hinweis auf geringere Heterosis bei Verwandtschaft der Eltern (f = 0,5; Geschwister-Linien bzw. Elter-Nachkomme) nachgewiesen werden konnte. Dieses steht im Widerspruch zu klassischen Befunden der Heterosisforschung. Es konnte eine signifikante Korrelation (r= 0,76, P= 0,01) zwischen der Heterosis der Samen und der Heterosis der Biomasse von (aus diesen Samen erwachsenen) Jungpflanzen nachgewiesen werden, woraus gefolgert wurde, dass die Samenheterosis dennoch, zumindest teilweise, ähnlichen genetischen Grundsätzen folgt wie die klassische Heterosis.Die Ergebnisse der vorliegenden Arbeit zeigen, dass Heterosis schon im frühen Entwicklungsstadium der Pflanze, am Samen, signifikant, bedeutend und mit großer Variation ausgeprägt ist. Es konnte abgeleitet werden, dass besonders die Heterozygotie für Allele, die die Samengröße der Eltern stark verschieden ausfallen lässt, in einem Samen dessen eigene Heterosis verursacht oder zumindest wesentlich bestimmt.

Red clover (Trifolium pratense) is currently used as a green fertilizer for agriculture in northern Sweden. However, due to its low resistance against diseases and a minimal benefit to local pollinators, there is a need to find alternative native species that maximize the benefits for pollinators and agriculture. Garden lupin (Lupinus polyphyllus), another legume, is an invasive alien species in Sweden that may affect the behavior of pollinators and therefore the pollination success of local plant species. The main aim of this study was to increase the knowledge of the legumes cow vetch (Vicia cracca), garden lupin, marsh pea (Lathyrus palustris) and red clover by observing their insect visitors and potential pollinators. The work was divided into subproject 1 (delprojekt 1) and subproject 2 (delprojekt 2). Delprojekt 1 studied insect visitation frequencies in one plot where garden lupin, cow vetch and red clover grew together in Burträsk, while delprojekt 2 studied insect pollination effectivity in two plots where one plot (Fäbodsanden) contained only marsh pea and the other plot (Skäret) contained both garden lupin and marsh pea. Data were collected via field observations. In ‘delprojekt 1', both bumblebees and solitary bees showed a significantly higher visit frequency to garden lupin than to cow vetch and red clover. In ‘delprojekt 2’, flies showed a significantly higher pollination effectivity on garden lupin than on marsh pea in Skäret. Both flies and bumblebees showed a significantly higher pollination effectivity on marsh pea in Fäbodsanden than in Skäret. This indicate that visitation frequencies to cow vetch and red clover as well as pollination effectivity on marsh pea may be affected by the presence/absence of garden lupin. For future studies, examples on how to extend the knowledge even further on plant-pollinator interactions are suggested.

While boreal forest habitats have historically been relatively free from invasive plants, there have been recent increases in the diversity and range of invasive plants in Alaska. It is critical that we understand how disturbances influence invasibility in northern boreal forests, to avoid the economic damage other regions have experienced from invasive plants. Black spruce (Picea mariana) is the dominant forest type in interior Alaska, and wildfire is the dominant disturbance in these forests. Furthermore, disturbances in the form of management for fire suppression are common in forests close to urban areas. I surveyed recently burned, managed, and undisturbed black spruce forests for invasive plants to determine if fire and management facilitate invasive plant colonization. I also conducted an experimental seeding trial with three invasive plants common to Alaska (bird vetch (Vicia cracca), common dandelion (Taraxacum officinale), and white sweetclover (Melilotus officinalis) in burned and mature black spruce forest to determine if fire facilitates invasive plant germination. To determine the effect of substrate type on invasive plant germination, I planted seeds on a variety of substrates in the burned forest. Results indicate that fire and fire suppression treatments promote invasive plant colonization, as invasive plants were observed in burned and managed areas, but not in mature stands. Analysis of environmental data taken at survey sites indicate that fire mediates invasibility through its effects on substrate quality. In burned stands, invasive plants are most likely to colonize areas of shallow post-fire organic depth. Results from the seeding trials were consistent with results from invasive plant surveys, with reduced germination in mature compared to burned forest, and no germination on the residual organic layer in the burned forest. The highest germination occurred on mineral soil in burned forest, indicating that severe fires that combust the organic layer are likely to increase invasibility. The results of this study suggest that invasive species control efforts should be prioritized to disturbed forests, particularly areas where the disturbance has exposed mineral soil.

In this revisional study based on the the genus Vicia in Central Anatolia large quantities of data have been compilled from specimens representing the group of the taxa being studied. These data were then synthesized to make taxon descriptions, keys, geographical distributions and ecological preferences. Since 2009, about 700 specimens have been collected from Central Anatolia and examined as the research materials. In addition, a large number of specimens have also been studied in the following herbaria ANK, GAZI, MUG, HUB and E. According to the Flora of Turkey (Davis 1985), there were 16 species found in Central Anatolia. But this study has shown that genus Vicia covers 22 species (V. noeana, V. anatolica, V. pannonica, V. hybrida, V. sericocarpa, V. narbonensis, V. galilaea, V. ervilia, V. caesarea, V. cracca, V. villosa, V. monantha, V. canescens, V. cappadocica, V. articulata, V. cassubica, V.peregrina, V. truncatula, V. grandiflora, V. lathyroides, V. cuspidata, V sativa) in this region. v Some morphological characters were used to understand whether they have a diagnostic value or not. These characters, which include habit, leaf, stem, inflorescence, calyx, corolla and style properties, were compared at infrageneric level and species level. Systematic value of pollen micromorphology, trichome micromorphology and petal epidermal micromorphology of Vicia in Central Anatolia were observed. Pollen grains equatorial view, polar view and exine ornamentations, trichome types of calyces and leaves can be useful for separating the species in sectional level. Geographical and ecological distributions maps were updated. In addition to this, the conservation status of the genus Vicia in Cental Anatolia was reassessed at regional level. The threat categories include 2 taxa DD, 1 taxon CR, 7 taxa EN, 1 taxon VU, 1 taxon NT and 14 taxa LC. The main threat categories for this genus are identified as overgrazing, constructions, land clearing and urbanizations. The infrageneric delimitations were performed by the use of multivariate analysis. Identification keys for sections and species were also given. Synonym, species updated descriptions, phenology, habitat, distribution in Central Anatolia, distribution in Turkey and general distribution, phytogeograpy, endemism, specimen citations photographs of species and distribution maps were also indicated.

V. faba fixes nitrogen effectively (Richards & Soper, 1979), however nitrogen fixation is reportedly energetically expensive and water deficit sensitive. Research was designed to determine whether medium nitrogen applications would result in increased productivities in V. faba, particularly during water deficits. Non-nodulated and nodulated V. faba were subjected to gradual water deficit imposition, and were supplied with a variety of medium nitrogen nutrition. Nitrogen fixing V. faba exhibited greater productivities than V. faba which were supplied with low medium nitrate concentrations (0.8 roM N), even during water deficits. Plant performance parameters (growth; net photosynthesis; nitrogen assimilatory enzyme activities; osmotic adjustment) were greater in nodulated than in non-nodulated 'no nitrate' supplied V. faba throughout water deficits, inferring water deficit tolerance for nitrogen fixation. However significantly greater plant performance paramaters were exhibited in V. faba when supplied with increasingly concentrated medium nitrogen nutrition (> 0.8 roM N) than when reliant on nitrogen fixation. In contrast to the bulk of previous literature, NR activities were maintained in V. faba until water deficits became severe, inferring a role for nitrate assimilation in nitrogenous osmotica production. Medium ammonia additions resulted in the exhibition of significantly increased root biomasses; cumulative leaf areas (important for a green manure crop); heights; and nitrogen assimilation in V. faba throughout water deficits, and accordingly in increased osmotic adjustment (including compatible solute accumulation), protein concentrations and vegetative yields. Greater plant productivities in v. faba when supplied with medium ammonia additions were attributed in part to lower associated assimilatory costs for ammonia than nitrate nutrition (Raven, 1992). Results indicated increased metabolism as opposed to storage of medium ammonia, and therefore potentially alleviated 'sink size' feedback inhibition of photosynthesis and nitrogen metabolism in V. faba when supplied with medium ammonia additions. Furthermore ammonia supplied V. faba may have been predisposed towards water deficit tolerance. In summary V. faba exhibited significantly greater nitrogen assimilation; osmotic adjustment; net photosynthesis; and growth when supplied with increasingly concentrated medium nitrogen nutrition (and particularly with medium ammonia additions) than when reliant on nitrogen fixation, both during periods of adequate irrigation and during water deficits.

Memoria para optar al título profesional de: Ingeniero Agrónomo

Brassinosteroids are plant hormones which are also known for their pleiotropic effects on plants exposed to various biotic and abiotic stress factors. The aim of this study was to evaluate the role of 10-8 M 24-epibrassinolide in Zea mays L. and Vicia faba L., grown under conditions of drought stress (6, 10, 14, 18 days) with an emphasis on different answer to their drought sensitive and resistant genotypes. Net photosynthetic rate (PN) and transpiration rate (E), stomatal conductance (gs), osmotic potential (ψs), proline (Pro) and malondialdehyde (MDA) content and membrane injury index (MI) were measured in stressed plants and plants grown under controlled conditions. The most important factor influencing these parameters was drought, which led to a gradual decrease of PN, E, gs, ψs and increase of Pro, MDA a MI. The effect of 24-epibrassinolid was significant rather exceptionally and in these cases, more pronounced response was observed in drought stressed plants compared with plants grown under controlled conditions. Plants showed intraspecific variability in their reactions, which in sensitive and tolerant genotypes were not clear and differed depending on the studied parameters and conditions of plant cultivation.

La incorporación de leguminosas en los agroecosistemas ganaderos, presenta una serie de ventajas productivas y ambientales, respecto a los sistemas basados únicamente en gramíneas. El objetivo del trabajo fue analizar el efecto de la incorporación de leguminosas en pasturas puras de agropiro alargado (Thinopyrum ponticum) en la región semiárida. Para ello, se condujeron una serie de experimentos con el objetivo de evaluar específicamente (1) el efecto de la intersiembra con vicia (Vicia villosa) sobre la biomasa forrajera, valor nutricional de la pastura y dinámica de las fracciones orgánicas del suelo en tres ambientes del sudoeste bonaerense (Bahía Blanca, Tornquist y Cabildo), (2) el efecto de la densidad de intersiembra con vicia o trébol de olor blanco (Melilotus albus), sobre los cambios de valor nutricional en función de la composición botánica, y por último, (3) determinar el momento de corte óptimo para la confección de reservas (heno o ensilaje) y estudiar el efecto de la incorporación de grano de cereal en ensilaje de pasturas consociadas. Las mezclas forrajeras se realizaron intersembrando vicia o trébol en otoño de cada año, sobre agropiro implantado. El forraje se cortó manualmente, sobre una superficie de 0,4 m2 y la frecuencia de defoliación estuvo basada en el crecimiento de agropiro. Durante un período de dos años sobre una pastura monofítica de agropiro y una consociación con vicia (20 kg ha-1), se evaluó la biomasa forrajera y su valor nutricional (FDN, FDA, LDA, DIVMS y PB). Durante este ensayo se realizó un fraccionamiento físico del suelo, para separar las diferentes fracciones que componen la materia orgánica hasta la profundidad de 0-20 cm. En otro ensayo, se decidió estudiar el efecto de las densidades de intersiembra, se incluyeron en este caso dos especies de leguminosas (vicia o trébol). Ambas, se intersembraron separadamente a tres densidades diferentes, en función de plantas agropiro:leguminosa (80:20, 70:30 y 60:40). Por su parte, para el estudio de reservas forrajeras, en otro ensayo, se cortó una pastura pura de agropiro en cinco estados fenológicos, desde vegetativo (7/11/2012) hasta grano pastoso (14/02/2013) para la elaboración de heno y ensilaje en cada fecha. Con esta información, en un último ensayo se estudió el efecto de la inclusión de una leguminosa (trébol) y grano de avena en ensilajes de agropiro. Las mezclas de forraje y grano se realizaron en laboratorio combinando tres proporciones de trébol (T0: sin trébol, agropiro puro; T20: 20% trébol y T40: 40% trébol) y dos niveles de grano (G0: sin grano y G1: 30% de grano) en base a la MS. Cuando se intersiembra vicia o trébol sobre agropiro, se registró en todos los sitios un aumento en la producción forrajera anual que fue del 28 a 190%, salvo para la localidad de Cabildo que la producción no cambió (p=0,08). Analizando la producción de agropiro separadamente no se observa una disminución con la inclusión de vicia. Por lo tanto, se entiende que la leguminosa acompañante, explora recursos que el agropiro no hace. En cambio, se encontró que trébol ejerció una competencia con agropiro avanzada la primavera, porque a medida que aumentó la biomasa de trébol disminuyó linealmente la biomasa de agropiro. Comparando la producción forrajera de vicia y trébol, ambas especies mostraron una buena capacidad de compensación en el crecimiento, ya que no mostraron diferencias en el rendimiento a diferentes densidades. En general, la intersiembra con leguminosas aumenta el contenido de PB (entre 1,0 y 1,4% cada 10% de leguminosa en la composición), DIVMS y LDA de la pastura, mientras que disminuyó los contenidos de FDN (1,5% cada 10% de leguminosa) y FDA. Además, se identificó trasferencia de nitrógeno de vicia y trébol hacia agropiro por mayor contenido de PB del agropiro consociado, tanto en primavera como en otoño. La inclusión de vicia incrementó el contenido de Carbono orgánico particulado (COP) grueso (hasta 42%) y fino (hasta 13%) del suelo, sin modificar el contenido de carbono orgánico total. Para Cabildo y Bahía Blanca la inclusión de vicia también generó un aumento (12%) del nitrógeno de la materia orgánica particulada. Respecto a la elaboración de reservas de agropiro, se encontró que el heno mantuvo mejor el valor nutricional que el ensilaje. Aunque, la mayor fuente de variación se relacionó al estado fenológico de la pastura en el momento de corte y no al tipo de reserva elaborada. Para la elaboración de un adecuado ensilaje de agropiro, el período óptimo de corte va desde espiga embuchada a antesis, mientras que para henificación el período óptimo es mayor, desde estado vegetativo hasta antesis. La incorporación de una leguminosa como el trébol y el grano de avena al ensilaje de agropiro generó aumentos en el contenido de PB y disminuciones en FDN, FDA. La adición de grano, mejora la DIVMS en los tratamientos con menor cantidad de trébol (T0 y T20). A medida que aumentó la participación de trébol, los valores de pH se incrementaron progresivamente de 3,78 (T0) a 4 (T40). Sin embargo, la adición de grano generó una disminución de pH. El ensilaje con trébol de olor blanco hasta el 40%, no presentó un problema para la realización de un adecuado ensilaje, resultando la mejor alternativa junto con la incorporación de grano. / The inclusion of legumes in livestock agroecosystems have production and environmental advantages, compared to systems based only on grasses. The objective of this work was to analyze the effect of the inclusion of legumes in pure pastures of tall wheatgrass (Thinopyrum ponticum). A series of experiments were conducted with the objective of evaluating, (1) the effect of interseeding hairy vetch (Vicia villosa) over the forage biomass, nutritional value of pasture and dynamics of soil organic matter fractions in three representative semiarid environments of the Buenos Aires province, Argentina (Bahía Blanca, Tornquist and Cabildo), (2) the effect of the density of interseeding with hairy vetch or white sweetclover (Melilotus albus) over nutritional value depending on the botanical composition, and finally, (3) determining the optimal cutting moment for the preparation of reserves and study the effect of the incorporation of grain in silage of mixture pastures. The forage mixtures were made by interseeding hairy vetch or clover in the autumn of each year, on implanted tall wheatgrass. The forage was cut manually, on a surface of 0,4 m2 and the frequency of defoliation was based on the growth of tall wheatgrass. During a two-year period, on tall wheatgrass monoculture and mixture with hairy vetch (20 kg ha-1), biomass yield and its nutritional value (NDF, ADF, ADL, IVDMD and CP) were evaluated. During this period, soil organic matter fractions were separated by size using a wet-sieving method up to the depth of 0-20 cm. Besides, to study the effect of interseeded densities, another test was realized that included two species of legumes (hairy vetch or white sweetclover). Separately, both legumes were interseeded at three different densities based on the tall wheatgrass:legume plant relationships of 80:20, 70:30 and 60:40. Finally, for the study of reserves, a pure pasture of tall wheatgrass was cut in five phenological stages from vegetative (11/7/2012) to dough-grain (2/14/2013) for the preparation of hay and silage on each date. With this information, in another trial the effect of the inclusion of a legume (clover) and grain of oats in silages of tall wheatgrass was studied. The mixtures of forage and grain were made in the laboratory combining three proportions of clover (T0: without clover, pure tall wheatgrass, T20: 20% clover and T40: 40% clover) and two grain levels (G0: no grain and G1: 30 % grain) based on the MS. When hairy vetch or clover was interseeded over tall wheatgrass, an increase in annual yield biomass was recorded from 28 to 190%, except in Cabildo, where production did not change. Analyzing tall wheatgrass biomass separately, there is no decrease in production with hairy vetch inclusion. Therefore, the accompanying legume, seems to use the resources that tall wheatgrass leaves available. Instead, the clover competed with tall wheatgrass in late spring, thus, as the biomass of clover increased, the biomass of tall wheatgrass decreased linearly. Hairy vetch and clover plants showed growth compensation because there was no difference in forage yield at different density. In general, the hairy vetch or clover interseeding increased total CP (between 1,0 - 1,4% every 10% of legume in the composition), IVDMD and ADL, while the NDF (1,5 % every 10% of legume in the composition) and ADF decreased. In addition, the nitrogen transfer from the legume appear to be responsible for the increase in the CP content of tall wheatgrass when growing together. This was evident in both seasons spring and fall. Hairy vetch increased the content of particulate organic carbon (POC) in fraction >105μm (up to 42%) and fraction between 53 and 105 μm (up to 13%) of the soil. The total organic carbon in soil (SOC) content did not change, therefore the relationship (POC/SOC) was increased. For Cabildo and Bahía Blanca hairy vetch inclusion enhanced the N content (12%) of the particulate organic matter. Regarding the preparation of wheatgrass reserves, it was found that hay maintained its nutritional value better than silage. Although, the greatest source of variation can be attributed to the phenological stage of the pasture and to a lesser extent to the type of reserve. For the best silage of tall wheatgrass, the optimal cutting period was from booting to anthesis, whereas, for haymaking the optimal period extends from vegetative to anthesis. Inclusion of clover and grain increased silage CP content and decreased NDF and ADF. In addition, grain incorporation improved IVDMD in treatments with less clover (T0 and T20). The highest proportion of clover in the mixture reduced FDN and FDA. As clover participation was greater, the silage pH values increased progressively from 3.78 (T0) to 4 (T40). However, the addition of grain decreased pH. According to these results, a silage including white sweetclover up to 40%, was not a restriction to obtain a fairly good quality silage, being the best alternative when also combined with grain.