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‣ Recovery of degraded pasture in Rondônia: macronutrients and productivity of brachiaria brizantha; Recuperação de pastagem degradada em Rondônia: macronutrientes e produtividade da brachiaria brizantha

NORONHA, Norberto Cornejo; ANDRADE, Cristiano Alberto de; LIMONGE, Fernando Célio; CERRI, Carlos Clemente; CERRI, Carlos Eduardo Pellegrino; PICCOLO, Marisa de Cássia; FEIGL, Brigitte Josefine
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica
Português
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37.087407%
Pasture is the main form of land use in Amazonia. Over time the pasture grass loses vigor and yields decrease, indicating a certain degree of degeneration. The main causes of degradation are lack of pasture maintenance and subsequent weed infestation, the choice of regionally unsuitable forage species and excessive grazing. The main purpose of this study was to evaluate the impact of different recovery managements on soil chemical properties and grass yield of a degraded pasture in Rondônia. For this purpose, an experiment was installed in October 2001, consisting of five treatments: C = control; HA = harrowing + NPK + micronutrients; HE = Herbicide + NK + micronutrients; R = No-tillage rice + NPK + micronutrients; and S = No-tillage soybean + PK + micronutrients. The following N, P and K sources were used: ammonium sulfate for N, calcined phosphate for P and potassium chloride for K. The experiment was arranged in a randomized block design with four replications. The shoot dry matter yield of the grass was analyzed as of the 35th month of experimentation, in a dry and a rainy period. Phosphorus fertilization resulted in significant increases in Ca2+ and Mg2+ and increasing trend of P in the topsoil in the initial months of the experiment in treatments HA and S and increases in Ca2+ and P (trend) in the treatment R. The cumulative production of Brachiaria brizantha...

‣ Yield and botanical composition of a mixed grass-legume pasture in response to maintenance fertilization; Produção e composição botânica de uma pastagem consorciada de gramínea e leguminosa em resposta à adubação de manutenção

ANDRADE, Carlos Mauricio Soares de; VALENTIM, Judson Ferreira; PEREIRA, João Batista Martiniano; FERREIRA, Aliedson Sampaio
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica
Português
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This study was carried out on a low-productive Brachiaria brizantha cv. Marandu pasture, mixed with Arachis pintoi cv. Belmonte (forage peanut), established 13 years ago in a Red-Yellow Latosol in Acre State, western Brazilian Amazon. The purpose was to evaluate the response of this pasture to different fertilizer combinations, aiming at identifying the nutritional factors responsible for the fall of pasture carrying capacity and for the reduced vigor of forage peanut. It was used a randomized complete block design, with three replications and 12 combinations of nitrogen, phosphorus, potassium, lime, sulfur, and micronutrients (100 kg/ha of N, P2O5 and K2O; 300 kg/ha of dolomitic lime; 30 kg/ha of sulfur and FTE BR-10). Fertilizers were broadcast in 5 × 5-m plots, and the experimental area was isolated from grazing for 35 days. Pasture response to fertilizations showed that nitrogen was the main limiting nutrient to forage production. The other nutrients, applied singly or in a combined way, without nitrogen source, did not change dry matter accumulation rate. Overall, fertilizations with nitrogen provided dry matter accumulation rate of 115 kg/ha/day in comparison to only 32 kg/ha/day when nitrogen was not applied. There was no response from forage peanut to fertilization...

‣ Balanço de nitrogênio em microbacias pareadas (floresta vs. pastagem) no estado de Rondônia.; Nitrogen balance in paired small catchments (forest vs. pasture) in Rondonia state.

Castellanos Bonilla, Adriana Lucia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 13/04/2005 Português
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O ciclo do nitrogênio vem sendo alterado pelas atividades antropogênicas, em função do incremento de culturas, como as leguminosas, a queima de combustíveis fósseis e o desmatamento de florestas para uso agrícola e pecuário. Em regiões de climas temperados, existem muitas informações sobre o ciclo biogeoquímico deste elemento e sobre o papel das alterações antropogênicas no mesmo. Entretanto, em regiões tropicais, onde o ritmo do desmatamento ainda é intenso, poucas são as informações sobre este elemento. Em função disto, o presente trabalho visa fornecer informações sobre possíveis alterações nas formas de nitrogênio transportadas por pequenos igarapés, após a conversão de florestas em pastagens de regiões tropicais. Para tal, selecionaram-se duas microbacias, uma coberta com floresta primária e outra com pastagem, no estado de Rondônia (Cacaulândia). Em ambas foram realizados balanços, por eventos de chuva, das formas e quantidades de nitrogênio transportadas desde a precipitação até a água dos rios. As coletas foram realizadas durante a estação chuvosa, de 21 de janeiro a 27 de fevereiro de 2004. Como resultado, observou-se: (1) um maior fluxo de água na microbacia da pastagem, e como conseqüência...

‣ Atributos microbiológicos do solo em área de pastagem irrigada com lâminas excedentes de efluente de esgoto tratado; Microbiological soil attributes of a pasture area with surplus irrigation of wastewater effluent

Paula, Alessandra Monteiro de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/12/2008 Português
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A irrigação de áreas agrícolas com efluentes de esgoto tratado (EET) é interessante e atrativa, quando realizada de forma controlada, pois além de possibilitar a liberação de recursos hídricos de melhor qualidade para outras atividades humanas, serve como uma forma de polimento dos efluentes provenientes do tratamento de esgoto por meio do filtro biológico constituído pelo sistema solo-planta. Entretanto, o reuso agrícola de efluentes é recente no Brasil e são poucos os estudos relacionados aos possíveis impactos dessa prática na qualidade dos solos tropicais. O presente estudo foi elaborado com o objetivo de avaliar o efeito de lâminas excedentes de irrigação de pastagem com capim Tifton, com efluente de esgoto tratado por 18 meses, na atividade microbiana, densidade de grupos funcionais, no potencial metabólico dos microrganismos e na estrutura da comunidade de bactérias oxidantes de amônio do solo. O experimento foi conduzido numa área de pastagem com capim-Bermuda Tifton 85 (Cynodon dactylon Pers. X C. niemfuensis Vanderyst) no município de Lins (SP), ao lado da estação de tratamento de esgoto operada pela Sabesp. Os tratamentos foram definidos a partir da lâmina de irrigação considerada adequada para a demanda hídrica da cultura (controle) e mais três lâminas com excesso de irrigação...

‣ Balanço de água e de nitrogênio em uma microbacia coberta por pastagem no litoral norte do Estado de São Paulo; Nitrogen and water budget of a small catchment covered by pasture in the north coast of Sao Paulo State, Brazil

Salemi, Luiz Felippe
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 16/06/2009 Português
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A Mata Atlântica é o bioma mais ameaçado do Brasil. Sua degradação substancial ocorreu desde a chegada dos europeus ao país por meio da mudança de uso solo e pela exploração da floresta. No entanto, pouco se sabe a respeito das conseqüências hidrológicas e biogeoquímicas da mudança de uso do solo nos domínios do referido ecossistema. Neste contexto, as microbacias hidrográficas têm sido objeto de muitos estudos devido sua alta sensibilidade aos processos hidrológicos e biogeoquímicos ocorrentes dentro delas. No presente estudo, calculou-se o balanço hídrico anual de uma microbacia coberta por pastagem na região do litoral norte do Estado de São Paulo. Essa bacia originalmente era coberta por floresta ombrófila densa. Em adição, amostrou-se água do escoamento do riacho, escoamento superficial, solução do solo (30, 50 e 90 cm de profundidade), água subterrânea, e precipitação de 05/12/2007 à 04/12/2008 para a análise de nitrogênio inorgânico. O conteúdo de nitrogênio (N-NH4 + e N-NO3 -) foi determinado por análise por injeção em fluxo (FIA). Com o intuito de elucidar os processos hidrológicos que geram escoamento direto, mediu-se a condutividade hidráulica do solo em condição de saturação a 15...

‣ Produção de leite de cabra em pastagem de Capim Tanzânia: avaliação de alternativas de manejo para produção sustentável em pasto cultivado; Goat milk production on Guineagrass pasture: evaluation of alternative management practices for sustainable production in cultivated pasture

Cavalcante, Ana Clara Rodrigues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/08/2010 Português
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A caprinocultura leiteira é uma atividade que contribui para a melhoria da geração de renda e emprego, em várias localidades do Nordeste do Brasil. O uso de pasto cultivado pode reduzir o efeito da estacionalidade e tornar sustentável a produção de leite de cabra utilizando pastagem. O objetivo deste trabalho foi determinar o efeito de tipos de manejo sobre o potencial de produção de leite de cabra em pasto de capim-tanzânia. O experimento foi conduzido na Embrapa Caprinos e Ovinos no Ceará (3°40´58.42 latitude sul; 40°1650.5 longitude e 79m de altitude). Foram utilizadas 65 cabras Anglo Nubianas, mantidas em pasto de capim-tanzânia manejado sob lotação rotativa, com taxa de lotação variável. Os manejos foram combinações entre alturas residuais do pasto (Altr) e doses de nitrogênio (N). Os manejos foram: intensivo (Altr=32,7 cm e 600 kg de N/ha ano-1); moderado (Altr=47,2 cm e 300 kg N/ha ano-1), leve (Altr=47,3 cm sem N) e extensivo (Altr=32,1 cm sem N). Foram avaliadas características na planta, no animal e no solo. As variáveis analisadas foram: o fluxo de biomassa através da morfogênese e as características estruturais do pasto, comportamento animal, o peso e o escore de condição corporal, produção de leite...

‣ Influência da transformação floresta - pastagem nos atributos do solo em área de agricultura familiar no oeste do Estado do Pará; Influence of forest-pasture transformation on soil attributes in family farm areas in the west county of Pará

Castilho, Selene Cristina de Pierri
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 02/07/2014 Português
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O crescente número de assentamentos na região Amazônica vem despertando discussões sobre sua importância no desmatamento da região, visto que a implantação dos assentamentos é sucedida pelo desmatamento e implantação de pastagens, modificando as condições químicas, físicas e biológicas do solo. O presente trabalho tem como hipóteses que 1 - a mudança de uso do solo de floresta para pastagem afeta negativamente os atributos físicos e químicos do solo; 2 - a mudança de uso do solo de floresta para pastagem reduz a abundância e diversidade da fauna do solo; 3 - As alterações nas condições físico-hídricas pela mudança de uso do solo condicionam a ocorrência de táxons da macrofauna e de espécies de minhocas. O objetivo deste trabalho é realizar análise qualitativa e quantitativa dos atributos físico-hídricos, químicos e da fauna do solo em dois usos do solo no Projeto de Assentamento Agroextrativista Praialta Piranheira, Nova Ipixuna, PA. Foram realizadas amostragens em duas topossequências (floresta e pastagem) nas posições topográficas de topo (T1), meia encosta (T2) e sopé (T3). As coletas foram realizadas em julho de 2012 (período seco) e janeiro e março de 2013 (período úmido), em cinco repetições para cada posição nas profundidades 0-0...

‣ Soil erodibility assessment in a pasture and forest remnant using the inderbitzen device

Ribeiro, A. I.; Gonzalez, L. F.; Longo, R. M.; de Medeiros, G. A.; Rosa, André Henrique; Lourenço, Roberto Wagner; Fengler, F. H.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 49-55
Português
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Brazil has the largest cattle herd in the world with approximately 200 million head. An important feature of the Brazilian cattle industry is that most of its herd is raised on pasture, which constitutes one of the most economical and practical ways to produce and provide food for cattle. However, this production model is mishandled and can lead to soil degradation. Maintaining soil quality is essential for the conservation of natural ecosystems and the areas of production, thus soil quality improves the conditions for biogeochemical cycles. In this context, the objective of this study was to develop a device for testing the Inderbitzen way of assessing soil erodibility in two situations of usage and occupation. Therefore, one area was used as a sample collection occupied by grazing and the other as a forest fragment; both located in the city of Sorocaba in Sao Paulo State, Brazil. Thus, we concluded that the proposed device - the Inderbitzen - proved capable of assessing soil erodibility of the pasture and remnant forest. Accordingly, there was a tendency for a smaller loss of forest soils in the remnant when compared to the degraded pasture. The greatest resistance of the soil erosion in the forest remnant may be associated with the amount of organic matter released by the forest litter in all its diversity...

‣ Defoliation patterns in signal grass tillers with varying heights in the same pasture

Santos, Manoel Eduardo Rozalino; Fonseca, Dilermando Miranda Da; Silva, Guilherme Porte; Braz, Thiago Gomes Dos Santos; Gomes, Virgilio Mesquita; Silva, Simone Pedro Da
Fonte: Editora da Universidade Estadual de Maringá (EDUEM) Publicador: Editora da Universidade Estadual de Maringá (EDUEM)
Tipo: Artigo de Revista Científica Formato: 259-265
Português
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The experiment was carried out to evaluate the patterns of defoliation in plants of various heights in the same pasture of Brachiaria decumbens cv. Basilisk under continuous stocking with cattle. Four plant heights were evaluated (10, 20, 30 and 40 cm) in the same managed sward, with mean height equal to 25 cm. A randomized blocks design was used, with two replications. Defoliation frequency increased linearly along with plant height in the same pasture. Defoliation intensity, number of defoliations in leaf blade and percentage of leaf blade grazed per tiller also increased linearly along with plant height. The defoliation interval decreased linearly according to plant height. The quadratic model was adequately fitted into grazing efficiency data, reaching the highest value (98%) at the sward site with 35 cm plants. The percentage variation in signal grass height showed a negative linear response with initial plant height. The structure of the pasture, characterized by the diversity in plant heights, is simultaneously the cause and consequence of the variability in defoliation patterns in individual tillers, which occur on the horizontal plane of the pasture.; O experimento foi conduzido para avaliar os padrões de desfolhação em plantas com alturas variáveis no mesmo pasto de Brachiaria decumbens cv. Basilisk sob lotação contínua com bovinos. Foram avaliadas quatro alturas de plantas (10...

‣ Evaluation of spatial and temporal variability of pasture based on topography and the quality of the rainy season

Marques da Silva, José Rafael; Peça, J. O.; Serrano, João M.; Carvalho, M. J.; Palma, Paulo M.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
Português
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Yield and botanical composition of a given dry-land pasture are heavily influenced by rainfall distribution, and vary according to topography. Through analyzing these parameters, it is possible to identify patterns of spatial distribution, related to topographic characteristics, which can be used to improve spatial management of pasture. The main objective of this project was to assess the role of rainfall, temperature and topography in the spatial and temporal variability of pasture and establish models for predicting the spatial distribution and yield of certain plant species, based on its topographic characteristics. This study was carried out over three years, 2004 to 2006, in a dryland pasture located in Southern Portugal. The data obtained were analyzed as a function of distance to flow lines and the results demonstrate that certain topographical characteristics, associated with agronomic information, can be very useful in explaining the spatial and temporal variability of yield and the botanical composition of the pasture. The slope of the linear regression of the variables mentioned can be used to estimate the spatial variation of yield and the botanical composition as a function of distance to flow lines. The regression coefficient can be estimated from the annual rainfall...

‣ Small scale soil variation and its effect on pasture yield in Southern Portugal

Serrano, João Manuel; Shahidian, Shakib; Marques da Silva, José R.
Fonte: Geoderma- Elsevier Publicador: Geoderma- Elsevier
Tipo: Artigo de Revista Científica
Português
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The general objectives of this study were to evaluate the specificity of the dynamics of soil parameters and to identify the determinant factors of pasture dry matter yield (DM) in a Mediterranean shallow soil. A topographic survey of the 6 ha experimental field was carried out using a real time kinematics GPS. Soil samples, geo-referenced with GPS, were collected in a depth range of 0 m to 0.30 m in 2004, 2005, 2006, 2007 and 2010. The apparent soil electrical conductivity (ECa) was measured using a Dualem 1S sensor under dry and wet conditions (2007 and 2010, respectively). Pasture samples, also geo-referenced with GPS, were collected between 2004 and 2007 to measure the pasture dry matter yield. A series of quantitative data analyses of soil and pasture parameters over the sampling years were carried out to identify the temporal stability as well as the inter-annual and inter-parameter correlations. The results demonstrate that the relative field elevation (RFE) has a significant influence on the dynamics of soil nutrients and, consequently, on the pasture yield variability. Also, it was possible to confirm, that, in Mediterranean shallow soils, RFE affects the spatial distribution of the soil moisture content (SMC) and bedrock depth...

‣ Effect of dietary dehydrated pasture and citrus pulp on the performance and meat quality of broiler chickens

Mourão, José Luís; Pinheiro, Victor; Prates, J.A; Bessa, R.J.; Ferreira, L.M.; Fontes, Carlos; Ponte, P.I.,
Fonte: Universidade de Trás-os-Montes e Alto Douro Publicador: Universidade de Trás-os-Montes e Alto Douro
Tipo: Artigo de Revista Científica
Português
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Some feedstuffs containing significant levels of fiber may be a good source of bioactive compounds that may contribute to improving broiler meat quality. However, high fiber level can have a negative impact on broiler performance. A study was undertaken to investigate the impact of incorporating citrus pulp (5 or 10%) or dehydrated pasture (5 or 10%) on the performance, carcass yield, and characteristics of broiler chickens. A diet containing neither citrus pulp nor dehydrated pasture was used as control. The results on growth performances showed that daily weight gain was reduced by 26% in birds of the 10% citrus pulp treatment (P<0.05). Compared with the control treatment, increases in feed intake occurred in birds consuming diets with 5 or 10% citrus pulp, which resulted in significantly higher feed conversion rates with the 10% level. Under the same incorporation rate, dehydrated pasture had effects less evident on the performances of broiler chicken. In addition, diets containing citrus pulp, displaying higher percentages of soluble nonstarch polysaccharides, increased small intestine relative length, and reduced carcass yield. Inclusion of 10% dehydrated pasture in diets resulted in improved breast skin yellowness (P<0.05). Finally...

‣ Pasture intake improves the performance and meat sensory attributes of free-range broilers

Ponte, P.I.P; Rosado, C.M.C; Crespo, J.P.; Crespo, D.G; Mourão, José Luís; Chaveiro-Soares, M.A.; Mendes, I.L.T.; Gama, L.T.; Prates, J.A.M.; Ferreira, L.M.A.; Fontes, Carlos
Fonte: Universidade de Trás-os-Montes e Alto Douro Publicador: Universidade de Trás-os-Montes e Alto Douro
Tipo: Artigo de Revista Científica
Português
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Free-range chickens are assumed to consume low to moderate levels of pasture, although the effects of forage intake in broiler performance and poultry meat quality remain to be established. In addition, despite cellulases and hemicellulases being widely used as feed supplements to improve the nutritive value of cereal-based diets for fast-growing broilers, the potential interest of these biocatalysts in the production of free-range chicken is yet to be established. In this study, broilers of the RedBro Cou Nu × RedBro M genotype were fed a cereal-based diet in portable floorless pens located either on a rainfed subterranean clover (Trifolium subterraneum) pasture or on an irrigated white clover (Trifolium repens) pasture. Control birds were maintained at the same site in identical pens but with no access to pastures. The importance of pasture intake and enzyme supplementation in the performance and meat sensory properties of the free-range chicken from d 28 to 56 was investigated. The results revealed that although cellulase and hemicellulase supplementation had no impact on broiler performance (P > 0.05), birds foraging on legume-based pastures reached significantly greater final BW. The data suggest that the improvement in broiler performance results from increased intake of the cereal-based feed rather than from an improvement in the efficiency of nutrient utilization per se. Interestingly...

‣ Effect of pasture biomass intake on growth performance and meat quality of free-range broilers

Ponte, Patrícia Isabel Pinheiro da
Fonte: Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária Publicador: Universidade Técnica de Lisboa. Faculdade de Medicina Veterinária
Tipo: Tese de Doutorado
Publicado em 02/06/2008 Português
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Tese de Doutoramento em Ciência e Tecnologia Animal; Os efeitos da ingestão de pastagem no desempenho produtivo e na qualidade da carne de frangos em crescimento, bem como o potencial interesse da suplementação das dietas destes animais com celulases e hemicelulases na produção de frangos ao ar livre continuam por avaliar. Os resultados obtidos neste trabalho revelam que a ingestão de pastagem incrementa o desempenho produtivo e contribui para a melhoria dos atributos sensoriais da carne de frango. No entanto, a ingestão de pastagem foi baixa em aves com acesso ad libitum ao alimento composto. A restrição da ingestão do alimento à base de cereais originou um aumento no consumo relativo de pastagem de leguminosas, promovendo o desempenho produtivo das aves. Por outro lado, a suplementação da dieta com celulases e hemicelulases não afectou o crescimento de frangos com acesso a pastagens à base de leguminosas. Os resultados sugerem que em aves de estirpes de crescimento lento criados em sistemas de produção ao ar livre, B-glucanases de origem desconhecida podem afectar a eficiência de enzimas exógenas adicionadas a dietas à base de cevada. A baixa ingestão de pastagem resultou num efeito moderado no perfil de ácidos gordos e homólogos da vitamina E na carne de aves provenientes de sistemas de produção ao ar livre. No entanto...

‣ Recovery of degraded pasture in Rondônia: macronutrients and productivity of brachiaria brizantha

Noronha,Norberto Cornejo; Andrade,Cristiano Alberto de; Limonge,Fernando Célio; Cerri,Carlos Clemente; Cerri,Carlos Eduardo Pellegrino; Piccolo,Marisa de Cássia; Feigl,Brigitte Josefine
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2010 Português
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Pasture is the main form of land use in Amazonia. Over time the pasture grass loses vigor and yields decrease, indicating a certain degree of degeneration. The main causes of degradation are lack of pasture maintenance and subsequent weed infestation, the choice of regionally unsuitable forage species and excessive grazing. The main purpose of this study was to evaluate the impact of different recovery managements on soil chemical properties and grass yield of a degraded pasture in Rondônia. For this purpose, an experiment was installed in October 2001, consisting of five treatments: C = control; HA = harrowing + NPK + micronutrients; HE = Herbicide + NK + micronutrients; R = No-tillage rice + NPK + micronutrients; and S = No-tillage soybean + PK + micronutrients. The following N, P and K sources were used: ammonium sulfate for N, calcined phosphate for P and potassium chloride for K. The experiment was arranged in a randomized block design with four replications. The shoot dry matter yield of the grass was analyzed as of the 35th month of experimentation, in a dry and a rainy period. Phosphorus fertilization resulted in significant increases in Ca2+ and Mg2+ and increasing trend of P in the topsoil in the initial months of the experiment in treatments HA and S and increases in Ca2+ and P (trend) in the treatment R. The cumulative production of Brachiaria brizantha...

‣ EFFECT OF FALLOW LAND, CULTIVATED PASTURE AND ABANDONED PASTURE ON SOIL FERTILITY IN TWO DEFORESTED AMAZONIAN REGIONS

DIEZ,J.A; POLO,A; DIAZ-BURGOS,M.A; CERRI,C.C; FEIGL,B.J; PICCOLO,M.C
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1997 Português
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The effect of two practices adopted by settlers (abandoned pasture and fallow land) on soil fertility of two deforested Amazonian regions (Belém-Pará and Ariquemes-Rondônia) was studied. Whenever possible, cultivated pasture, over similar time periods in both cases and in natural forest, were employed as soil fertility reference standards. Nutrient dynamics was studied using the electroultra-filtration technique. In general, deforestation, as practiced in these areas, has a degrading effect on soil fertility. The effect of burning normally leads to a pH rise caused by ash. This usually yields a favorable transitory effect, improving soil fertility conditions, however not sufficient for plant needs, as inferred from the low P and K levels. Cattle excrements, improved the K level for cultivated pastures. Qualitative differences related to N were observed between cultivated pasture and both, fallow land or abandoned pasture. In the first, a certain recovery of available N levels was detected, mainly affecting the EUF-Norg fraction. On the other hand, a regeneration of organic compounds, in the fallow land and the abandoned pasture, closely related to those existing in the natural forest, was verified. This is mainly due to the presence of a higher proportion of NO3-_N and...

‣ Recovery of degraded pasture in Rondônia: macronutrients and productivity of Brachiaria brizantha.

NORONHA, N. C.; ANDRADE, C. A. de; LIMONGE, F. C.; CERRI, C. C.; CERRI, C. E. P.; PICCOLO, M. de C.; FEIGL, B. J.
Fonte: Revista Brasileira de Ciência do Solo, Viçosa, v. 34, n. 5, p. 1711-1720, 2011. Publicador: Revista Brasileira de Ciência do Solo, Viçosa, v. 34, n. 5, p. 1711-1720, 2011.
Tipo: Artigo em periódico indexado (ALICE)
Português
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SUMMARY: Pasture is the main form of land use in Amazonia. Over time the pasture grass loses vigor and yields decrease, indicating a certain degree of degeneration. The main causes of degradation are lack of pasture maintenance and subsequent weed infestation, the choice of regionally unsuitable forage species and excessive grazing. The main purpose of this study was to evaluate the impact of different recovery managements on soil chemical properties and grass yield of a degraded pasture in Rondônia. For this purpose, an experiment was installed in October 2001, consisting of five treatments: C = control; HA = harrowing + NPK + micronutrients; HE = Herbicide + NK + micronutrients; R = No-tillage rice + NPK + micronutrients; and S = No-tillage soybean + PK + micronutrients. The following N, P and K sources were used: ammonium sulfate for N, calcined phosphate for P and potassium chloride for K. The experiment was arranged in a randomized block design with four replications. The shoot dry matter yield of the grass was analyzed as of the 35th month of experimentation, in a dry and a rainy period. Phosphorus fertilization resulted in significant increases in Ca2+ and Mg2+ and increasing trend of P in the topsoil in the initial months of the experiment in treatments HA and S and increases in Ca2+ and P (trend) in the treatment R. The cumulative production of Brachiaria brizantha...

‣ Development of a novel crop-pasture system for mixed farms in the higher rainfall zone of southern Australia.

Roberts Craig, Penny
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2011 Português
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The use of annual-based pasture and/or annual crops is now common practice in the higher rainfall regions of southern Australia where livestock grazing is the traditional practice. The lower water use of these annual-based systems, compared with systems based on perennial pastures, exacerbates issues of waterlogging, rising watertables and salinity in these regions. For environmental reasons farming systems used in the higher rainfall regions should target the use of more perennials in the landscape, but this should not be done at the expense of farm productivity or profitability. Intercropping, where the pasture component of the system is a perennial species, may provide the opportunity to maintain or improve farm productivity whilst delivering favourable environmental outcomes. A study of crop/perennial pasture intercrops is the core investigation undertaken in this thesis. Perennial pasture species lucerne (Medicago sativa) and chicory (Cichorium intybus) were established and maintained for three seasons with annually sown (2006-08 seasons) crop species (wheat (Triticum aestivum), lupin (Lupinus angustifolius) and canola (Brassica napus)), in a double skip row arrangement. These intercrops were compared for production, resource use and farm productivity with the individual crops and pastures grown as monocultures. Yields of grain crops were reduced when grown in intercrop with lucerne and chicory. Grain yield reductions ranged from 0-46% for wheat...

‣ Effect of fallow land, cultivated pasture and abandoned pasture on soil fertility in two deforested Amazonian regions

Díez López, José Antonio; Polo, Alfredo; Díaz-Burgos, M. A.; Cerri, C. C.; Feigl, B. J.; Piccolo, M. C.
Fonte: Scientia Agrícola Publicador: Scientia Agrícola
Tipo: Artículo
Português
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The effect of two practices adopted by settlers (abandoned pasture and fallow land) on soil fertility of two deforested Amazonian regions (Belém-Pará and Ariquemes-Rondônia) was studied. Whenever possible, cultivated pasture, over similar time periods in both cases and in natural forest, were employed as soil fertility reference standards. Nutrient dynamics was studied using the electroultra-filtration technique. In general, deforestation, as practiced in these areas, has a degrading effect on soil fertility. The effect of burning normally leads to a pH rise caused by ash. This usually yields a favorable transitory effect, improving soil fertility conditions, however not sufficient for plant needs, as inferred from the low P and K levels. Cattle excrements, improved the K level for cultivated pastures. Qualitative differences related to N were observed between cultivated pasture and both, fallow land or abandoned pasture. In the first, a certain recovery of available N levels was detected, mainly affecting the EUF-Norg fraction. On the other hand, a regeneration of organic compounds, in the fallow land and the abandoned pasture, closely related to those existing in the natural forest, was verified. This is mainly due to the presence of a higher proportion of NO3- - N and...

‣ DESEMPENHO PRODUTIVO DE VACAS HOLANDESAS EM PASTAGEM DE MILHETO E FEIJÃO MIÚDO COM E SEM SUPLEMENTAÇÃO; PRODUCTIVE PERFORMANCE OF HOLSTEIN COWS IN A MIXED PASTURE OF PEARL MILLET AND COWPEA WITH AND WITHOUD SUPLEMENTATION

HANISCH, Ana Lúcia; Epagri; ABREU DA SILVA, Marcelo; Universidade Federal do Rio Grande do Sul; MEDEIROS, Renato Borges de; Universidade Federal do Rio Grande do Sul
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf; application/pdf
Publicado em 16/12/2010 Português
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Holstein cows milk production were evaluated under two grazing management systems: a mixed pasture of pearl millet (Pennisetum glaucum (L.) R. Brown) and cowpea (Vigna unguiculata L.) with or without supplementation to the animals, during the period of 18/12/2000 a 20/02/2001. Twelve multipara cows of the Holstein breed were used. They were selected by their production potential, live weight (LW) and lactation period. After the stratification, the animals were randomly distributed between the two treatment groups of the experiment: animals kept under grazing in a mixed pasture of pearl millet and cowpea; and animals kept in the same pasture receiving supplementation in a daily basis. The experiment was carried out in a completely randomized design. The average dry matter was 2469 kg ha-1 at the entrance and 1554 kg ha-1 at the animal exit from the enclosed pasture. The harvest pasture dry matter presented 16.5 dag kg-1 of crude protein, 68.5 dag kg-1 of neutral detergent fiber and 70.25 dag kg-1 of digestibility in vitro of organic matter. The average participation of Cowpea in the mixture pasture was 12%. There was a significant difference in milk production of milk between the two grazing systems treatments. The average milk productions were 19.56 kg day-1 to cows receiving only pasture and 23.40 kg day-1 to the ones supplemented. The supplementation promoted more stability in cow milk production between the evaluation periods.; Foi avaliado o desempenho produtivo de vacas da raça Holandesa mantidas em pastagem consorciada de milheto (Pennisetum glaucum (L.) R. Brown) e feijão miúdo (Vigna unguiculata L.)...