Dairy producers across the country are evaluating the effectiveness of management intensive grazing (MIG) systems as a means of reducing the economic pressures of confinement feeding and manure handling. Systems using MIG have been promoted as an environmentally safer way of managing nutrient balance on Center. However, little research has been conducted to evaluate how these systems affect phosphorus (P) loss from the Center through runoff and forage removal. The goal of this study was to investigate the effects of forage type and manure density on P levels in runoff from release plots that simulated a MIG dairy system. Two forage treatments were planted on runoff release plots and applied with three manure density treatments and four replications of each combination for a total of 24 plots. Orchardgrass (Dactylis glomerata) and a broad-leafed forage treatment consisting of buckhorn plantain (Plantago lanceolata), red clover (Trifolium pratense), and alfalfa (Medicago sativa) were planted on the runoff release plots in early spring. Manure densities with no manure (control), a density simulating a low stocking density (low), and a density simulating high stocking density (high) were applied to plots during grazing simulations. Six rainfall simulations were conducted over the season simulating grazing conditions when forage was removed and re-growth conditions when forage had reached its target re-growth height before re-grazing occurred. Thirty minutes of runoff was collected from the runoff release plots to determine first flush phosphorus losses from the various treatments. Mass losses of total phosphorus (TP) for manure treatments in series 1 were significant due to plot installation disturbance. No significant effect for ortho-phosphorus (ortho-P), particulate phosphorus (PP) or TP concentration or mass losses were observed for other simulation series. Significantly higher mass losses were observed in series 1 for both forage treatments, again due to installation disturbance. Seasonal mass losses for TP were significantly lower for the orchardgrass treatment. Forage mass removal over the season increased as the stands established. Orchardgrass treatments appeared to control P losses earlier in the season, while broadleaf treatments observed a steady increase in ortho-P losses up to series 5. Both mass and concentration losses of TP were controlled earlier in the season by orchardgrass, while PP showed no significant mass or concentration loss effects. / Master of Science

Thesis (PhD(Agric))--Stellenbosch University, 2011. / ENGLISH ABSTRACT: Exogenous fibrolytic enzymes (EFE) as additives in ruminant feeds are being researched worldwide. Promising effects on dry matter intake (DMI), digestibility and production in especially dairy cows, but also feedlot steers and even sheep have been observed. However, lack of or negative effects are also reported and the need arises for clarity on the mode-of-action of EFE. Forages are characterised as being highly heterogenic and contain varying concentrations of fibre. The fibre, in turn, varies greatly in digestibility, due to the chemical as well as anatomical build-up of this complex carbohydrate. Fibre, however, presents a major source of potential energy for ruminant animals and EFE is a viable option to increase the digestibility of forages. Therefore, a study with the aim of establishing whether EFE can affect the digestibility of forages, how it affects the digestibility and the clarification of the mode-of-action was drafted. From the literature, the first objective was readily attained and clear indications exist that EFE can indeed improve animal performance when their diets are treated with such enzymes. From the current study, it was shown that EFE can alter the rate and extent of gas production of certain forages (lucerne, kikuyu and weeping love grass) and also improve the in vitro digestibility thereof (P < 0.05). This is in agreement with other research findings and it was concluded that these effects were likely exerted during the early stages of digestion. A complete feed for sheep, when treated with the EFE, showed positive effects on the in sacco digestibility, as well as on the digestion kinetics of the feed (P < 0.05). The in vitro digestibility of the complete feed was also improved due to EFE treatment (P < 0.05). The observations on in vitro digestibility were less marked when a purified xylanase, obtained from the partial purification of the EFE cocktail, was used as the sole fibrolytic enzyme treatment. It is apparent, therefore, that enzyme specificity plays a major role in obtaining positive effects on digestibility of forages and feeds. In agreement with the literature, it is proposed that the approach to improve the digestibility of forages should be to use EFE cocktails containing various enzymes, matching the complexity of the substrate. The major aim of the study was, however, an in depth investigation of the mode-of-action of EFE. This aim was approached by observing changes in plant tissue material at the histological level upon treatment with EFE and incubation in buffered rumen fluid. Results showed that EFE had subtle, yet significant effects on cell wall material for the various tissues studied (P < 0.05). The major effect observed here was that EFE had a thinning effect on the cell wall thickness (P < 0.05). It was deduced that as EFE affected the cell wall of the plant material, earlier access by microorganisms could be achieved. Also, nutrients caught in the cell wall matrix could then be released for digestion. Therefore, observations that EFE increases the rate of digestion, as well as the extent of digestion of not only fibre, but also protein, were explained by the enzyme’s action on cell wall material. It was concluded that there is definite merit in the use of EFE to improve the digestibility of ruminant feeds and that this is partly related to effects on the cell walls of the forages. The effects can be expected to occur during the early stages of digestion, thereby potentially increasing the passage rate of digesta from the rumen. Additionally, the effect of the EFE is not limited to fibre and increased digestibility of all nutrients can be expected, thereby increasing the overall digestibility of the feed. Future research should further elucidate the mode-of-action of EFE using advanced technologies routinely employed in the plant sciences. Additionally, the main potential advantage of EFE treatment lies in improving the digestibility of poor quality roughages. Unfortunately, this is an area where limited positive effects are observed and in depth investigations should be undertaken to classify the specificity and optimum conditions of EFE to better match the complexity of the substrate being treated. / AFRIKAANSE OPSOMMING: Eksogene fibrolitiese ensieme (EFE) word tans wêreldwyd ondersoek vir die gebruik daarvan as voerbymiddels vir herkouers. Belowende effekte op DMI, verteerbaarheid en produksie van vernaam melkbeeste, maar ook voerkraalbeeste en selfs skape is al gerapporteer. Swak en selfs negatiewe effekte word egter ook waargeneem en daarom is ʼn deeglike ondersoek na die metode van werking van EFE van belang. Ruvoere word gekenmerk deurdat dit heterogeen van aard is en bevat variërende vlakke van vesel. Vesel maak op sy beurt ʼn wesenlike deel uit van die ruvoer, maar varieer baie in verteerbaarheid weens die chemiese sowel as anatomiese samestelling van hierdie komplekse koolhidraat. Ruvoer verteenwoordig egter ʼn goeie bron van potensiële energie vir herkouers en EFE word voorgestel as ʼn haalbare behandeling om die verteerbaarheid daarvan te verhoog. Dus is ʼn studie beplan met die doelwit om die effekte van EFE te definieer, hoe dit verteerbaarheid beïnvloed en die metode van werking daarvan te ondersoek. Vanuit die literatuur is dit duidelik dat daar wel baie positiewe effekte is waar ruvoere met EFE behandel is en dat diereproduksie wel bevoordeel word daardeur. Vanuit die studie is dit getoon dat die tempo en hoeveelheid gasproduksie van sekere ruvoere (lusern, kikuyu en oulandsgras) verbeter word deur EFE behandeling (P < 0.05). Hierdie bevinding was ondersteun deur verbeterde in vitro verteerbaarheid van die ruvoere (P < 0.05). Dit is in ooreenstemming met literatuur en die gevolgtrekking is gemaak dat hierdie effekte tydens die vroeëre stadia van vertering verwag kan word. ʼn Volledige skaapvoer wat met EFE behandel is, het positiewe effekte op in sacco verteerbaarheid en verterings kinetika data gehad (P < 0.05). Weereens is die in vitro verteerbaarheid van die voer verbeter (P < 0.05). Waarnemings op in vitro verteerbaarheid was veel minder opvallend wanneer ʼn gesuiwerde xylanase as enigste fibrolitiese ensiem behandeling gebruik is. Dit is dus duidelik dat ensiem spesifisiteit ʼn belangrike rol speel in die verkryging van positiewe resultate in die verteerbaarheid van ruvoere en veevoere. In ooreenstemming met literatuur word dit voorgestel dat ensiemmengsels wat verskeie ensieme bevat as EFE gebruik behoort te word ten einde aan die kompleksiteit van die substraat te voldoen. Die hoof doelwit van die studie was egter ʼn indiepte ondersoek na die metode van werking van EFE. Hierdie doelwit is benader deur die effekte van EFE op selwand strukture van plantmateriaal op ʼn histologiese vlak te ondersoek. Die ruvoere was vooraf met EFE behandel en in vitro geïnkubeer in rumen vloeistof. Die resultate het getoon dat EFE ʼn matige, dog betekenisvolle effek op die selwand materiaal van die onderskeie weefsels gehad het (P < 0.05). Die belangrikste waargeneemde effek was dat EFE ʼn verdunningseffek op die selwande gehad het. Dit is afgelei dat as EFE die selwand kan beïnvloed, mikro-organismes vroeër toegang tot die inhoud kan kry. Verder, nutriënte vasgevang in die selwand matriks raak ook beskikbaar vir vertering. Hierdie afleiding en die effek van EFE op selwande verklaar waarnemings dat EFE die tempo van vertering sowel as die vlak van vertering van nie net vesel, maar ook proteïen kan bevoordeel. Die gevolgtrekking is gemaak dat daar definitiewe meriete is in die gebruik van EFE om die verteerbaarheid van herkouervoere te verbeter en dat dit verband hou met die ensiem se werking op selwande van die ruvoere. Die effekte kan verwag word tydens die vroeë stadia van vertering om dus deurvloeitempo van digesta te verbeter. Die effek van die EFE is verder nie beperk tot vesel nie, maar positiewe effekte op ander nutriënte kan verwag word en vervolgens ʼn algehele verhoging in die verteerbaarheid van die voer. Navorsing behoort in die toekoms verder die metode van werking van EFE te ondersoek deur gebruik te maak van gevorderde tegnologie wat alledaags gebruik word in die Plantwetenskappe. Die belowendste aanwending van EFE lê in die verbetering in vertering van swak kwaliteit ruvoere. Dit is ongelukkig juis hier waar min positiewe resultate gerapporteer word en indiepte navorsing moet onderneem word om ensiem spesifisiteit en optimum kondisies te definieer sodat EFE beter opgewasse is teen die kompleksiteit van die substraat.

A utilização de leguminosas na produção de ruminantes pode propiciar benefícios como a melhora no desempenho animal; redução das emissões de metano (CH4), principalmente em razão da presença de taninos; e o aumento na disponibilidade de nitrogênio no solo, devido à fixação deste elemento realizada por estas plantas. A macrotiloma (Macrotyloma axillare - NO 279) é uma leguminosa de clima tropical que se caracteriza por apresentar baixos teores de taninos, com risco reduzido de causar efeitos antinutricionais, mas que ainda carece de estudos a respeito de seus efeitos em ruminantes. Objetivando-se determinar os efeitos dos taninos da macrotiloma sobre a fermentação ruminal in vitro e avaliar a digestibilidade aparente, desempenho produtivo, emissão de CH4, fermentação ruminal, características de carcaça e perfil de ácidos graxos da carne em ovinos alimentados com esta leguminosa, foram realizados os estudos aqui descritos. No primeiro estudo, realizou-se um bioensaio in vitro para se verificar os efeitos dos taninos sobre a fermentação ruminal e produção de gases; e um ensaio in vivo de digestiblidade aparente dos nutrientes, com 12 cordeiras, divididas em 2 tratamentos: dieta exclusiva de feno de gramínea tropical (CON); e dieta de feno de gramínea suplementada com feno de macrotiloma (MAC) (gramínea:leguminosa, 75:25). In vitro, verificou-se menor (p < 0,05) produção total de gases (PTG) e CH4 nas amostras incubadas sem polietilenoglicol (PEG), ou seja, as que estavam sujeitas aos efeitos dos taninos, e no ensaio in vivo, maior digestibilidade da proteína bruta (PB), maior produção de nitrogênio amoniacal (N-NH3) na fermentação ruminal e menor contagem de protozoários ruminais nas cordeiras MAC (p < 0,05) foram observadas. Já no segundo estudo, foi realizado um ensaio de desempenho animal de 90 dias, com 14 cordeiros Santa Inês, divididos em 2 tratamentos, CON e MAC, conforme descrito anteriormente. Neste caso, além do desempenho, também foram avaliados a emissão de CH4 pela técnica do gás traçador hexafluoreto de enxofre (SF6), parâmetros de fermentação ruminal, características de carcaça e perfil de ácidos graxos da carne. Não se observou efeito da macrotiloma (p > 0,05) sobre o consumo de matéria seca (CMS), ganho em peso médio diário (GMD), emissão de CH4, produção de ácidos graxos de cadeia curta (AGCC), características de carcaça e perfil de ácidos graxos. Na avaliação dos parâmetros ruminais, observou-se maior (p < 0,05) concentração de N-NH3 para os animais MAC; maior (p < 0,05) contagem de protozoários nos animais CON; e menor abundância relativa de metanogênicas nos animais MAC (p < 0,05). Mesmo não tendo influenciado o desempenho produtivo e emissão de CH4, as menores produção de CH4 in vitro e contagens de protozoários, a maior produção de N-NH3 e a diminuição das metanogênicas denotaram à macrotiloma potencial como alimento para ruminantes e como alternativa a ser avaliada em novos estudos relacionados à mitigação de CH4 no sistema de produção / Using legumes in ruminant production system may provide benefits such as improvement in animal performance; decrease in methane (CH4) emissions, mainly due to the presence of tannins; and increase in nitrogen soil availability, due to the fixation of this element carried out by these plants. Macrotiloma (Macrotyloma axillare - NO 279) is a tropical legume which is characterized for presenting low concentrations of tannins, providing reduced risks of antinutritional effects, but still has few studies regarding its effects on ruminants. The studies described here aimed to determine the effects of macrotiloma tannins on the in vitro ruminal fermentation, and to evaluate apparent digestibility, productive performance, CH4 emission, ruminal fermentative parameters, carcass characteristics and fatty acids profile of the meat in sheep fed this legume. At the first study, an in vitro bioassay was performed to evaluate gas production and ruminal fermentation, while an in vivo trial was carried out to determine apparent digestibility of nutrients using 12 ewes, divided into 2 treatments: exclusive tropical grass hay diet (control - CON); and tropical grass hay diet supplemented with macrotiloma hay (macrotiloma - MAC) (grass:legume, 75-25). In the in vitro assay, reduced total gases (TGP) and CH4 production were observed in the samples incubated without polyethylene glycol (PEG), that is, those which were subject to effects of tannins (p < 0.05) and in the digestibility trial, increased crude protein (CP) digestibility and ruminal ammoniacal nitrogen (NH3-N), as well as reduced protozoa count were observed for the ewes fed MAC (p < 0.05). In the second study, a 90 days growth performance assay was performed, with 14 Santa Inês lambs divided into 2 treatment groups, CON and MAC, as previously described. In addition to growth performance, CH4 emission by using the sulphur hexafluoride (SF6) tracer technique, ruminal fermentative parameters, carcass characteristics and fatty acids profile of meat were evaluated. No difference (p > 0.05) was observed between the lambs of the groups CON and MAC for dry matter intake (DMI), average daily gain (ADG), CH4 emission, short chain fatty acids production, carcass characteristics as well as for fatty acids profile of meat. Evaluating ruminal fermentative parameters, increased concentration of NH3-N in the rumen fluid and reduction of both, protozoa count and relative abundance of methanogens were observed for the animals fed MAC (p < 0.05) when compared to those fed CON. Even though macrotiloma has not influenced productive performance and CH4 emission, the decrease observed for in vitro CH4 production and in vivo protozoa count, as well as the increased NH3-N production and the reduction in methanogens have denoted potential to macrotiloma as a ruminant feed and as an option for being evaluated in further studies regarding CH4 mitigation in the production system

O Andropogon L. é uma gramínea forrageira, amplamente distribuída em áreas de Cerrado e com períodos de seca prolongada. Apresenta características de ser denso com grandes touceiras e com inflorescência plumosa, tendo uma elevada capacidade na disseminação de suas sementes. Por sua vez, as sementes são consideradas principais fontes de abrigo e transporte de agentes patogênicos para áreas livres de doenças. No Tocantins, não há registros de trabalhos que relacionem a incidência de fungos em sementes de Andropogon como causadores de doenças em culturas de importância agrícola. Da mesma forma, não há pesquisas sobre o transporte, transmissibilidade e patogenicidade de fungos associados à suas sementes. O trabalho objetivou avaliar a qualidade sanitária de sementes do Andropogon, a transmissão de fungos via semente-plântula e a patogenicidade à plantas de outras espécies de importância agrícola, e também realizar a caracterização morfológica e molecular de Curvularia sp. isolados de sementes de Andropogon. Os experimentos foram conduzidos no Laboratório de Pesquisa em Fitopatologia, Laboratório de Controle Biológico de Doenças e Casa de Vegetação da Universidade Federal do Tocantins. No capítulo 1, utilizou-se o método blotter test para a avaliação da sanidade das sementes com e sem desinfestação. A incidência dos fungos foi avaliada a partir da análise individual das sementes com auxílio de microscópio estereoscópico e ótico. A germinação das sementes foi avaliada após 10 dias de instalação do teste, juntamente com a identificação de fungos associados às sementes não germinadas. Para os fungos detectados na análise sanitária avaliou-se a capacidade de transmissão via semente-plântula. A patogenicidade dos fungos oriundos das sementes de Andropogon foi avaliada por meio da inoculação na própria planta e também foi avaliada a capacidade destes fungos em infectar outras plantas de interesse econômico. No capítulo 2, a identificação morfológica foi realizada a partir de observações macro e micromorfológicas utilizando-se como base as características descritas na literatura quanto ao aspecto da colônia e conídios de Curvularia sp. A caracterização molecular foi realizada a partir da extração do DNA, amplificação e sequenciamento da região do gene Clg2p. A transmissão foi avaliada a partir da semeadura de sementes sem tratamento com fungicidas, onde ao final de 40 dias observou-se sintomas típicos de mancha foliar de Curvularia. A patogenicidade foi avaliada a partir da inoculação de suspensão de conídios de Curvularia sp. nas folhas de plantas sadias, observando ao final de 10 dias, se houve sintomas do patógeno. Foram identificados e quantificados nas sementes de Andropogon L. fungos dos gêneros Alternaria sp., Bipolaris sp., Curvularia sp., Fusarium sp., Phoma sp., Aspergillus sp., Cladosporium sp., Penicillium sp. e Rhizopus sp. A realização da desinfestação das sementes reduziu os fungos presentes nas sementes. O fungo Curvularia sp. foi transmitido das sementes para as plantas de Andropogon. As sementes de Andropogon L. transportaram e disseminaram fungos que uma vez inoculados causaram infecção na própria planta e em outras culturas de importância econômica, tais como: arroz, feijão-caupi, melancia, melão, milho, sorgo e aos capins marandu, mombaça, piatã e quicuia. Baseado em marcadores morfológicos e moleculares, o fungo identificado com elevada incidência associado às sementes de Andropogon coletadas em diferentes regiões produtoras agrícolas, trata-se de Curvularia lunata. C. lunata é transmitido para as plantas de Andropogon via semente, sendo patogênico a esta espécie de gramínea forrageira, causando manchas necróticas foliares. / Andropogon L. is a forage grass, widely distributed in Cerrado areas and with prolonged drought periods. It presents dense characteristics with large clumps and with plumose inflorescence, with high capacity in the seeds dissemination. In turn, seeds are considered the main sources of shelter and transport of pathogens to disease-free areas. In Tocantins, there are no studies records relate the fungi incidence in Andropogon grass seeds as diseases cause in agricultural importance crops. Likewise, there is no research about the transport, transmissibility and pathogenicity of fungi associated with their seeds. The work aim was evaluate the sanitary quality of Andropogon grass seeds, the fungi transmission by seed-seedlings and the fungis pathogenicity to other species plants of agricultural importance, and also perform the Curvularia sp. morphological and molecular characterization, isolated from Andropogon grass seeds. The experiments were conducted at the Phytopathology Research Laboratory, Biologic Control of Disease Laboratory and green house of Tocantins Federal University. In chapter 1, the blotter test method was used to evaluate seed health with and without disinfestation. The fungi incidence was evaluated from seeds individual analysis using stereoscopic and optical microscope. The seeds germination was evaluated after 10 days after test installation, together with the fungi identification associated with non-germinated seeds. For the detected fungus in the sanitary analysis was evaluated the transmission capacity of seed-seedling. The fungi pathogenicity from the Andropogon seeds grass was evaluated by inoculation in the plant itself and was also evaluated the ability of these fungi to infect other plants of economic interest. In chapter 2, the morphological identification was performed from macro and micromorphological observations using as basis the characteristics described in literature regarding the aspect of the colony and conidia of Curvularia sp. Molecular characterization was performed from DNA extraction, amplification and sequencing gene Clg2p region. Transmission was evaluated from seed sowing whitout treatment with fungicides, where at the end of 40 days typical leaf spot symptoms of Curvularia. The pathogenicity was evaluated from the inoculation of conidia suspension on leaves of healthy plants, observing at the end 10 days, if there were symptoms of the pathogen. Were identified and quantified in the seeds of Andropogon L. fungi of the genera Alternaria sp., Bipolaris sp., Curvularia sp., Fusarium sp., Phoma sp., Aspergillus sp., Cladosporium sp., Penicillium sp. and Rhizopus sp. The seed disinfestation reduced the fungi present in the seeds. The fungus Curvularia sp. it was transmitted seed to Andropogon plant. Andropogon L. seeds carried and spread fungi the once inoculated caused infection in the plant itself and other economically important crops, such as rice, cowpea, watermelon, melon, corn, sorghum and grasses marandu, mombaça, piatã and quicuia. Based on morphological and molecular markers, the fungus identified with high incidence associated with Andropogon seeds collected in different agricultural producing regions, is Curvularia lunata. C. lunata is transmitted to plants of Andropogon by seed, being pathogenic to this species of forage grass, causing foliar necrotic spots.

O presente trabalho teve por objetivo avaliar cenários futuros de produção de forragem em pastagens de Panicum maximum cv. Tanzânia no Estado de São Paulo, baseados nos modelos climáticos ETA-CPTEC e PRECIS, e discutir os impactos potenciais das mudanças climáticas globais sobre a pecuária na região. Foram realizadas simulações de taxa de acúmulo de matéria seca utilizando-se um modelo de estimativa de produção considerando o acúmulo de graus-dia e a introdução da variável armazenamento de água no solo como fator de penalização do modelo para as condições de sequeiro. Os dados gerados foram espacializados para a geração dos mapas de cenário atual e futuros conjuntamente com a análise dos cenários climáticos com base nas emissões de gases do efeito estufa, cenário de baixa, média e alta emissão, projetados pelos modelos climáticos para os anos de 2025 e 2055. Concluiu-se que nos cenários futuros de produção, as mudanças climáticas irão favorecer o estabelecimento do capim-tanzânia no Estado de São Paulo em áreas que atualmente são limitantes ao seu desenvolvimento e ocorrerá um aumento de produção nas áreas atuais de exploração. A pecuária no Estado de São Paulo poderá se beneficiar com as mudanças climáticas pela influência positiva no crescimento de pastagens de capim-tanzânia. / This study aimed to evaluate future production scenarios of tanzânia guineagrass (Panicum maximum cv. Tanzania) in São Paulo State, based on climate models ETA-CPTEC and PRECIS, and discuss the potential impacts of global climate changes around the livestock in the region. Was simulated dry matter accumulation rate using a production estimative model considering the accumulation of degrees-day and an introduction of the variable soil water storage as a penalization factor in the model for rainfed conditions. The data was spatialized for the generation of actual and future production scenarios together with analysis of the climatic scenarios based on greenhouse gases emissions, low, medium and high emissions scenarios, projected for the years 2025 to 2055. It was concluded that future production scenarios with the predicted climate changes will favor the development of guineagrass in the São Paulo State especially in currently limited areas for development and will occur an increase in production from current exploration areas. The livestock in the São Paulo State may benefit from climate change by the positive influence on the growth of the guineagrass.

Agriculture is one of the main sources of phosphorous and nitrogen (P and N) contributing to cultural eutrophication of freshwater lakes and estuaries. In cold regions, the effects of agricultural management practices used to mitigate the runoff loss of these nutrients remain uncertain. In particular, the use of forage crops and minimum tillage, have not reduced some forms of P and N in runoff to streams, in part, as a result of freeze-thaw induced losses of mobile P and N from forages and crop residues. The purpose of this research is to improve the current understanding of the controls on P and N loss from Canadian Prairie fields to ultimately aid in the development and evaluation of beneficial agricultural management practices that perform predictably in cold regions. This study aims to provide new insights into the effects of cold regions hydrological processes on runoff quality through the development and application of a novel inductive - deductive modelling approach. Runoff flowpaths resulting from the three infiltration regimes identified for frozen soils (Granger et al., 1984) are hypothesized to impact the chemistry of field scale meltwater runoff by varying meltwater interaction with agricultural soils and vegetation. Hydrochemistry data from six intensively monitored minimum tillage and forage cropped fields in South Tobacco Creek, Manitoba were used to develop a nutrient model to integrate with a physics-based hydrological modelling platform that can represent the frozen soil infiltration regimes, in addition to other important cold region hydrological processes. The inductive development of a nutrient model, integrated with a deductive physics-based hydrological platform, enabled the modelling of meltwater flowpaths and freeze-thaw induced losses from vegetation. Further testing of the developed model and field experimentation are required to test the hypothesis that runoff generated over a basal ice layer eliminates the transfer of soil nutrients to runoff. Comparison of predicted and observed field scale runoff concentrations and masses suggest that this method of inductive-deductive model development has potential to predict the performance of agricultural management practices in cold regions.

L'objectif de cette thèse est d'arriver à mieux contraindre les paramètres qui contrôlent les processus d'altération à l'échelle d'un petit bassin versant, en se focalisant plus précisément sur le rôle de l'hydrologie. Pour ce faire, les variations temporelles et spatiales des signatures chimiques et isotopiques (U, Sr) des eaux du bassin versant du Ringelbach (Vosges, France) sont étudiées. Plusieurs sources de ce bassin versant, essentiellement composé d'un granite plus ou moins fracturé, ont été échantillonnées mensuellement sur une période de deux ans, le long d'un profil altitudinal. Ce bassin versant présente également l'avantage d'être équipé de trois forages profonds (allant jusqu'à 150 mètres de profondeur) qui ont permis de prélever à la fois les roches et les eaux profondes. Sur la base de l'interprétation géochimique des eaux, la connectivité des différents compartiments hydrologiques a été évaluée et un schéma de fonctionnement hydrogéochimique est proposé s'appuyant sur une bonne connaissance du contexte géologique. Enfin, un taux d'altération et un flux d'eau sont estimés à partir d'une modélisation de l'évolution du rapport isotopique de l'uranium (234U/238U) le long d'un trajet d'eau. L'originalité de cette étude est également de coupler cette approche de traçage géochimique avec une approche modélisatrice en utilisant le logiciel KIRMAT (Kinetic Reactions and Mass transport) qui intègre les équations des réactions géochimiques (dissolution/précipitation) et les équations de transport (1D). Il est ainsi possible de simuler le transport réactif d'une eau traversant la roche le long d'un certain trajet d'eau. Cette modélisation s'appuie sur la caractérisation minéralogique, des propriétés physiques des échantillons de roches prélevés le long des forages et sur les interprétations géochimiques des eaux. Ainsi, la modélisation de la composition chimique des eaux de sources et des eaux de forages a permis d'affiner la compréhension des processus d'altération, notamment le rôle des phases secondaires précipitées. Celle-ci permet également une meilleure compréhension des phénomènes de couplage entre les différents paramètres qui contrôlent la signature chimique des eaux à l'échelle du bassin versant.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-01-04T14:03:51Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ivana_pires_sousa_baracho.pdf: 881653 bytes, checksum: 116255ef5aa789c8ed97b09f4b8417c8 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-01-31T16:57:04Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ivana_pires_sousa_baracho.pdf: 881653 bytes, checksum: 116255ef5aa789c8ed97b09f4b8417c8 (MD5) / Made available in DSpace on 2017-01-31T16:57:04Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) ivana_pires_sousa_baracho.pdf: 881653 bytes, checksum: 116255ef5aa789c8ed97b09f4b8417c8 (MD5) Previous issue date: 2016 / Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG) / Objetivou-se com este trabalho avaliar o efeito da compacta??o do solo e diferentes doses de nitrog?nio no desenvolvimento, produtividade e qualidade de esp?cies forrageiras e nos atributos f?sicos do solo. Foram montados tr?s experimentos independentes em casa de vegeta??o com um delineamento em blocos casualizados, em um esquema fatorial duplo. Os experimentos foram com as tr?s esp?cies forrageiras - Bachiaria ruzizienses, Brachiaria brizantha cv. MG-5 Vit?ria e Panicum maximum cv. momba?a; os tratamentos: quatro Graus de Compacta??o (GC) ? 65%; 75%; 85% e 95% e quatro dose de adubo nitrogenado ? 0; 200; 250 e 300 Kg de N ha-1), com quatro repeti??es. O experimento foi conduzido em vasos em casa de vegeta??o localizada na UFVJM campus JK, em Diamantina-MG. No local de coleta do solo utilizado no experimento, foram coletadas amostras de aproximadamente 5 kg para a realiza??o do ensaio de Proctor normal, determinando-se a Densidade do solo e a Umidade para cada corpo de prova. Uma vez estipulado o GC, conhecendo a Densidade m?xima do solo e o volume do vaso, foi poss?vel calcular a massa de solo a ser colocada dentro dos vasos referente a cada GC. As amostras foram coletadas 90 dias ap?s semeadura, para realiza??o das avalia??es em laborat?rio. As vari?veis analisadas nas plantas foram: produ??o de massa verde (MV) e massa seca (MS) da parte a?rea, altura, volume da raiz, prote?na bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ?cido (FDA) e lignina. Para a realiza??o do ensaio de Resist?ncia do solo ? penetra??o (RP), as amostras indeformadas foram trabalhadas e saturadas por um per?odo de 48 h, em seguida deu-se in?cio ?s leituras de RP. Realizou-se tamb?m a avalia??o de RP em vasos contendo solo compactado com GC de 95%, antes da semeadura; a modelagem foi feita ajustando um modelo exponencial de RP x umidade e foram comparados estatisticamente por um teste de identidade de modelos. Concluiu-se que a MV, MS da parte a?rea, a altura de plantas e o teor de prote?na bruta aumentaram linearmente com a aplica??o de nitrog?nio em todas as forrageiras estudadas. ? medida que se aumentam as doses de nitrog?nio, os teores de FDN e FDA em todas as forrageiras estudadas diminu?ram. Para o volume da raiz, a Brachiaria brizantha cv. MG-5 Vit?ria respondeu linearmente e positivamente ?s crescentes doses de nitrog?nio no solo compactado. Na avalia??o dos atributos f?sicos do solo, o solo cultivado com Brachiaria ruziziensis foi o que apresentou uma maior RP na umidade na capacidade de campo no grau de compacta??o de 95%. As tr?s esp?cies forrageiras t?m capacidade de al?vio da estrutura do solo compactado; por?m, a Brachiaria brizantha cv. MG-5 Vit?ria demonstrou ser a mais eficiente. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2014. / The objective of this study was to evaluate the effect of soil compaction and different doses of nitrogen, in the development, productivity and quality of forage species and in soil physical properties. Three independent experiments were performed in a greenhouse with a randomized block design, in a double factorial. The experiments were with three forage species Bachiaria ruzizienses, Brachiaria brizantha cv. MG-5 Vit?ria and Panicum maximum cv. momba?a: the treatments: Four Degrees of Compaction (GC) ? 65%; 75%; 85% and 95% and four doses of nitrogen fertilizer? 0; 200; 250 e 300 Kg de N ha-1), with four replications. The experiment was conducted in pots in a greenhouse located at UFVJM JK campus, Diamantina-MG. At the site of the soil sampling used in the experiment, samples of 5kg approximately were collected to perform the normal Proctor test, determining soil density and humidity for each specimen. Once stipulated the GC, knowing the maximum density of the soil and the pot volume, it was possible to calculate the mass of soil to be placed in the pots for each GC. The samples were collected 90 days after sowing, to carry out evaluations in the laboratory. The variables analyzed in plants were: green mass production (MV) and dry matter (MS) of the shoot, height, root volume, crude protein (PB), neutral detergent fiber (FDN), acid detergent fiber (FDA) and lignin. To carry out the soil penetration resistance test (RP), the undisturbed soil samples were worked and saturated for a period of 48 h, next we started the RP readings. It was also performed the evaluation of RP in pots containing compacted soil with a 95% GC, before sowing and the modeling was performed by adjusting an exponential model of RP x humidity and they were compared statistically by an identity test of models. It was concluded that the MV, MS of the shoot, height of plants and crude protein content increased linearly with the application of nitrogen in all the studied forages. As it increases the nitrogen levels, the levels of FDN and FDA in all studied forages decreased. For the root volume, the Brachiaria brizantha cv. MG-5 Vit?ria responded linearly and positively to increasing doses of nitrogen in compacted soil. In the evaluation of soil physical properties, the soil cultivated with Brachiaria ruziziensis was the one that presented a higher RP in humidity at field capacity in the degree of compaction of 95%. The three forage species have relief capacity of the compacted soil structure, however, the Brachiaria brizantha cv. MG-5 Vit?ria proved to be the most efficient one.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-09-28T19:28:43Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) mariane_rodrigues_ferreira.pdf: 1446137 bytes, checksum: b0c55b008bb6208223dfeaa66f8b1e31 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-10-09T14:21:58Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) mariane_rodrigues_ferreira.pdf: 1446137 bytes, checksum: b0c55b008bb6208223dfeaa66f8b1e31 (MD5) / Made available in DSpace on 2017-10-09T14:21:58Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) mariane_rodrigues_ferreira.pdf: 1446137 bytes, checksum: b0c55b008bb6208223dfeaa66f8b1e31 (MD5) Previous issue date: 2017 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Objetivou-se com este trabalho determinar o melhor m?todo de estima??o dos coeficientes de repetibilidade e as melhores combina??es entre cortes de acordo com a estabiliza??o genot?pica para caracter?sticas agron?micas, estimar par?metros gen?ticos e formar grupos morfofuncionais com base nas caracter?sticas morfog?nicas e estruturais por meio do agrupamento de Otimiza??o de Tocher em gen?tipos de Panicum maximum. Os coeficientes de repetibilidade para produ??o de massa seca total (MST), massa seca foliar (MSF), massa seca do colmo (MSC), porcentagem de folhas (%F), porcentagem de colmo (%C), foram estimados por meio de quatro m?todos: an?lise de vari?ncia (ANOVA), an?lise estrutural com base na m?dia dos coeficientes de correla??o (AECOR), an?lise de componentes principais com base na matriz de covari?ncia (CPCOV) e na matriz de correla??es (CPCOR). Para o estudo da estabiliza??o genot?pica, utilizaram-se os coeficientes estimados pela ANOVA e CPCOR. Para a avalia??o das caracter?sticas morfog?nicas foram estimadas: taxa de aparecimento foliar (TAPF), filocrono (FIL), taxa de alongamento foliar (TALF), taxa de senesc?ncia foliar (TSF), comprimento final da l?mina (CFL), n?mero de folhas vivas (NFV), dura??o de vida das folhas (DVF), taxa de alongamento de pseudocolmo (TALC), n?mero m?dio de perfilhos (NMP), rela??o l?mina:colmo (RLC). Para MST, foram observados coeficientes de repetibilidade variando entre 0,3500 e 0,4300 pelos m?todos da ANOVA e CPCOR, respectivamente. Altos coeficientes de repetibilidade tamb?m foram encontrados para a caracter?stica MSF. Baixos coeficientes de repetibilidade foram observados para %F e %Ce rela??o l?mina:colmo. Para estabiliza??o genot?pica da MST, os melhores coeficientes foram observados para a combina??o entre os cortes 6 a 7 e entre os cortes 5 a 8, enquanto os menores coeficientes foram observados quando se utilizaram apenas os cortes 3 a 4 e de 1 a 2, em ambos os m?todos. Para a rela??o l?mina:colmo, os melhores coeficientes foram registrados para os cortes 6 a 7 pelo m?todo da ANOVA, e 1 a 2 pelo m?todo CPCOR. De maneira geral, a combina??o entre os cortes de 6 a 7, tamb?m proporcionou maior repetibilidade e determina??o, otimizando a estabiliza??o dos gen?tipos para as massas e porcentagens de folha e de colmo. No estudo dos par?metros gen?ticos e agrupamento, foi observado que somente as caracter?sticas TALF, CFL e RLC tiveram o componente vari?ncia gen?tica significativo. Apesar disto, as caracter?sticas TALC, NFV, apresentaram coeficientes de varia??o genot?picos (CVg) superiores aos coeficientes de varia??o residual ou ambiental (CVe). As caracter?sticas TAPF, FIL, DVF e TSF apresentaram valores abaixo da unidade para a raz?o CVg/CVe. Alta raz?o CVg/CVe foi observada para as caracter?sticas RLC, NFV, TALC, TALF, CFL, sendo os maiores coeficientes foram registrados para RLC. Ap?s o agrupamento, constatou-se a forma??o de cinco grupos morfofuncionais. Os grupos que apresentaram maiores valores de TALF foram os grupos 3, 5 e 1 com valores superiores ? m?dia geral de todos os gen?tipos avaliados. Enquanto o grupo 4 obteve menor desempenho para esta caracter?stica. Para a TALC o grupo 2 se destacou, seguido pelo grupo 5. Dentre todos os grupos a maior RLC constada foi para o grupo 4 e para CFL o grupo 3. Conclui-se que os m?todos que proporcionaram os melhores coeficientes de repetibilidade de determina??o foram os dos componentes principais com base na matriz de correla??o e de covari?ncia. Para a estabiliza??o genot?pica, os melhores coeficientes de repetibilidade e determina??o s?o observados para os cortes realizados no segundo per?odo das ?guas. As caracter?sticas TALF, CFL e RLC apresentam variabilidade gen?tica significativa, e as caracter?sticas TAPF, FIL, DVF e TSF apresentam baixa raz?o CVg/CVe e necessitam de maior controle ambiental. Os grupos 3, 5 e 1, apresentam altas taxas de alongamento de folha como mecanismo de ac?mulo de forragem. J? o grupo 4 se destaca pela capacidade de perfilhamento. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Zootecnia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / The objective was to evaluate the coefficient of repeatability of the agronomic traits and to estimate the breeding value of morphogenic characteristics to stablish morphofunctional groups in the clustering analysis of Tocher in Panicum maximum genotypes. The repeatability coefficients were estimated by four methods: analysis of variance (ANOVA), structural analysis based on the correlation matrix (EACOR), principal component analysis based on the variance and covariance?s matrix (PCCOV) and principal component analysis based on the correlation matrix (PCCOR). To the genotypic stabilization study, the ANOVA and PCCOR were used. To the morphogenic evaluation, the characteristics were estimated: leaf appearance rate (LAR), phillochron (PHC), leaf elongation rate (LER), leaf senescence rate (LSR), number of live leaves (NLL), leaf life spam (LLS), leaf final length (LFL), stem elongation rate (SER), average number of tillers (ANT) and leaf:stem ratio (LSR). To total dry matter were observed repeatability coefficients ranging from 0.3500 to 0.4300 by the ANOVA and PCCOR methods, respectively. High coefficients of repeatability were estimated to leaf dry mass too. Low coefficients of repeatability were observed to percentage of leaves, stems and leaf:stem ratio. In the genotypic stabilization of total dry mass the higher coefficients were observed between the 6 and 7th harvest and between the 5 and 8th harvest, while the lowest coefficients were observed when the harvests 3 to 4 and 1 to 2 were considered in both methods. To leaf:stem ratio the higher coefficients were observed to harvests between 6 and 7 in the ANOVA method and 1 to 2 in the PCCOR method. In general, the combination between the 6 and 7th harvests also improves the repeatability and determination coefficients, optimizing the stabilization of the genotypes to dry mass and percentage of leaf and stems. In the study of genetic parameters and clustering, were observed significant effect to genetic variance component only to LER, LFL and LSR. In spite of this the characteristic SER and NLL had CVg higher than CVr. The characteristics LAR. PHC, LLS and LSR had CVg/CVr above the unity. High CVg/CVr ratio were observed to LSR, NLL, SER, LER and LFL, so that the highest coefficient observed to LSR. After the clustering analysis was found five morphofunctional groups. The groups with higher LER were 3, 5 and 1 with breeding values above the general mean. The group 4 had lowest LER. The groups 2 and 5 had the highest SER and the highest LSR was observed to the group 4. The group 3 showed high LFL. It was possible to conclude that the total and leaf dry mass have higher coefficient of repeatability, indicating better accuracy in the identification of the superior genotypes of P. maximum. In the genotypic stabilization, the higher coefficient and determination were observed to the harvests realized in the rainy period. The morphogenic characteristics that have the highest genetic variance have more possibility of gains with the selection and the traits with low CVg/CVr ratio need more environmental control. The groups 3, 5 and 1 have high potential to forage production duly its high leaf elongation rate.

In the Caatinga is inserted a wide variety of native species, mostly deciduous and potential for forage use. However, the use of these species has been carried out without proper knowledge of the productive potential and almost no environmental control technique, there is need for more studies on the native plants of Caatinga. This study aimed to analyse arbustive-arboreal component of Four Caatinga species with forage potential for their incorporation in animal feed in the cities of Olho D'Água do Casado and Delmiro Gouveia, Alagoas. The experimental areas amount to a total of 1 ha of native Caatinga, which was subdivided into 100 plots of 10 mx 10 m, where it was analyzed the floristic and phytosociological arbustive-arboreal component of Caatinga and from this selected four species of arbustive-arboreal stratum with forage potential Pilosocereus gounellei F. A. C. Werder ex K. Schum Byles & G. D. Rowley, Pityrocarpa moniliformis (Benth.) Luckow & R. W. Jobson, Laetia apetala Jacq and Capparis flexuosa L. common in both environments, five times each. It was conducted a mapping distribution of the four selected species in the two areas and made bromatological chemical analysis, which evaluated the dry matter content (DM), mineral matter (MM), organic matter (OM), crude protein (CP), ethereal extract (EE), Neutral detergent fiber (NDF), acid detergent fiber (ADF) and Lignin (LIG). Questionnaires were administered together with farmers to identify the species used as forage for animals and how to use and management. The chemical components of the species P. gounellei, P. moniliformis, L. apetala and C. flexuosa indicates that the tree and shrub layer Caatinga can be a food source for ruminants of the semiarid region, especially in the dry season; The association of the species P. gounellei that have water and food supply with other species native to the Caatinga that have higher levels of dry matter becomes a viable alternative to ruminant feed of the semiarid region, especially in water-scarce period; The species C. flexuosa is indicated as good forage for animal feed, the dry matter, crude protein, mineral matter, neutral detergent fiber and lignin, and although it has a high ethereal layer content, has good palatability and available throughout the year can be associated with other plants in the diet of the animal; The species P. moniliformis is an excellent forage because the nutritional values present in its composition, achieving meet the nutritional needs of animals, with great availability in the Caatinga, and the ease of handling; The species L. apetala has high crude protein presenting itself as a good food and medicinal option for flocks of semi-arid region; Cattle breeding of Settlements Nova Esperança (Olho D'Água Casado) and Maria Bonita (Delmiro Gouveia) consists of small herds distributed among cattle, sheep and goats raised extensively in the Caatinga; The species of Caatinga producers more use in animal feed are Cereus jamacaru (Mandacaru) Pityrocarpa moniliformis (Angelim), Spondias tuberosa (Umbuzeiro) Pilosocereus gounellei (Xique-xique), identified as the toughest in the dry season; Of the four species analyzed P. moniliformis presents aggregate spatial distribution in the two experimental areas. / Fundação de Amparo a Pesquisa do Estado de Alagoas / Na Caatinga encontra-se inserida uma grande variedade de espécies nativas, em sua maioria caducifólia e com potencial para uso forrageiro. No entanto, a utilização dessas espécies vem sendo exercida sem o devido conhecimento do potencial produtivo e quase nenhuma técnica de controle ambiental, havendo necessidade de mais estudos em relação as plantas nativas da Caatinga. Nesse sentido objetivou-se analisar o componente arbustivo-arbóreo de quatro espécies da Caatinga com potencial forrageiro, visando sua incorporação na alimentação animal nos municípios de Olho D’Água do Casado e Delmiro Gouveia, Alagoas. As áreas experimentais perfaz um total de 1 ha de Caatinga nativa, a qual foi subdivida em 100 parcelas de 10 m x 10 m, onde foi analisado os levantamentos florístico e fitossociológico do componente arbóreo-arbustivo da Caatinga e a partir deste selecionadas quatro espécies do estrato arbustivo arbóreo com potencial forrageiro Pilosocereus gounellei F. A. C. Werder ex K. Schum Byles & G. D. Rowley (Xique-xique), Pityrocarpa moniliformis (Benth.) Luckow & R. W. Jobson (Angelim), Laetia apetala Jacq (Pau piranha) e Capparis flexuosa L.(Feijão bravo) comuns nos dois ambientes e com cinco repetições cada. Foi realizado mapeamento de distribuição das quatro espécies selecionadas nas duas áreas e feita análise químico bromatológico, onde foram avaliados os teores de Matéria seca (MS), Matéria mineral (MM), Matéria orgânica (MO), Proteína bruta (PB), Extrato etéreo (EE), Fibra em detergente neutro (FDN), Fibra em detergente ácido (FDA) e Lignina (LIG). Também foram aplicados questionários junto aos produtores rurais para identificação das espécies utilizadas como forrageira pelos animais e a forma de uso e manejo. A composição química bromatológica das espécies P. gounellei, P. moniliformis, L. apetala e C. flexuosa L. indica que o estrato arbóreo e arbustivo da Caatinga podem se constituir fonte alimentar para os ruminantes da região Semiárida, sobretudo no período de estiagem; A associação da espécie P. gounellei que dispõe de fonte de água e alimento com outras espécies nativas da Caatinga que possuam maiores teores de matéria seca torna-se uma alternativa viável para alimentação de ruminantes da região Semiárida, notadamente no período de escassez hídrica; A espécie C. flexuosa é indicada como boa forrageira para alimentação animal, pelos teores de matéria seca, proteína bruta, matéria mineral, fibra em detergente neutro e lignina, e embora disponha de um elevado teor de estrato etéreo, apresenta boa palatabilidade e esta disponível durante todo o ano podendo ser associada com outras plantas na dieta dos animais; A espécie P. moniliformis é uma excelente forrageira devido os valores nutricionais presentes em sua composição, conseguindo suprir as necessidades nutricionais dos animais, apresentando grande disponibilidade na Caatinga, além da facilidade de manejo; A espécie L. apetala apresenta altos teores de proteína bruta apresentando-se como uma boa opção alimentar e medicinal para os rebanhos da região Semiárida; A produção pecuária dos Assentamentos Nova Esperança (Olho D’Água do Casado) e Maria Bonita (Delmiro Gouveia) é composta por pequenos rebanhos, distribuídos entre bovinos, ovinos e caprinos criados extensivamente na Caatinga; As espécies da Caatinga que os produtores mais utilizam na alimentação animal são Cereus jamacaru (Mandacaru), Pityrocarpa moniliformis (Angelim), Spondias tuberosa (Umbuzeiro) Pilosocereus gounellei (Xique-xique), apontadas como as mais resistentes no período de estiagem; Das quatro espécies analisadas P. moniliformis apresenta distribuição espacial agregada nas duas áreas experimentais.