O presente estudo foi dividido em três capitulos, todos realizados na Estação Experimental de Ciências Florestais de Anhembi/SP, entre os anos de 2014 e 2015. O primeiro estudo intitulado de \"Variação mensal da fitomassa da forragem em função do grau de cobertura do dossel em sistemas silvipastoris\", foi realizado em 3 monoculturas de 13 anos de idade, com área útil de 50 m x 30 m para coleta de pasto as mesmas efectuadas mensalmente. Os resultados apresentaram que não há relação significativa entre a cobertura do dossel e fitomassa da forragem pelo caso de que o sub-bosque estava muito sombreado. Entretanto, houve uma relação indireta entre área basal e fitomassa. Evidenciando-se que o talhão de Eucalipto urograndis apresentou as melhores condições de crescimento e disponibilidade de materia seca mensal para Bachiaria decumbens além de obter a maior porcentagem de folha entre todos os tratamentos. Ao contrario, no talhão de Pinus tecunumanii, foi encontrada a menor disponibilidade de materia seca mensal e por consequência, menor porcentagem de folha. O segundo estudo foi chamado de: \"Disponibilidade de fitomassa de B. decumbens, em um sistema silvipastoril com eucalipto: o papel da radiação\" onde o componente florestal foi o eucalyptus (COP-1377) de 2 anos de idade plantado em uma área útil de 10 ha, dividido em 3 tratamentos (onda longa-OL (39 m), onda curta-OC (21 m), e testemunha-T) e instalado em 4 blocos distintos. Foram realizadas duas coletas dutante o período de verão e de inverno, onde foi possível verificar que o tratamento OL mostrou maior disponibilidade de fitomassa a 65% de irradiância além de obter maior porcentagem da fração folha. Este foi favorecido pelo maior espaçamento entre as aléias. Contudo, houve ataque de cigarinha na pastagem, mantendo a queda da disponibilidade no período de inverno. O terceiro estudo intitulado de: \"Variaçoes arquiteturais de uma monocultura de E. urograndis em função de sua posição espacial\", foi também realizado na monocultura do primeiro estudo, numa área de 7 ha. Para este estudo, realizou-se um inventario florestal, logo após, dividiu-se as árvores por sua classe diamétrica e selecionou-se aleatoriamente 60 árvores para cubagem, e destas, escolheu-se 15 para determinação da fitomassa e respectiva densidade da madeira. Para a obtenção da fitomassa dividiu-se as árvores em três frações de análise: tronco, galhos e folha. Além disso, as 15 árvores foram divididas em: bordadura, intermediária e centro da parcela, de acordo com a sua localização. Verificou-se que a bordadura apresentou os maiores crescimentos em DAP, altura, largura de copa e, que por consequência, obteve maior volume e fitomassa em todas suas frações. Também foi possível observar que tanto a bordadura quanto o centro apresentaram maior densidade básica em função da maior copa e altura das árvores incentivando a geração de mais fitomassa foliar. Finalmente conforme os três estudos realizados neste trabalho de pesquisa, concluiu-se que a radiação solar é fator chave na produtividade da cultura forrageira, demonstrando a necessidade de mais pesquisas sobre os sistemas agroforestais e silvipastoris para o sucesso de futuros emprendimentos. / This study was divided into three chapters, all of these were held in Forest Science Experiment Station of Anhembi / SP, between the years 2014 and 2015. The first study entitled of \"Monthly variation of biomass of forage due to the canopy cover degree in silvipastoral systems\" was fulfilled in 3 monocultures with 13 years of age, with useful area of 50 m x 30 m for pasture collecting the same month. The results showed no significant relationship between canopy cover and biomass of forage because of the shading of the understory. However, there was an indirect link between baseline and biomass area. Indicating that the that plot of Eucalyptus urograndis showed the best conditions of growth and availability of monthly dry matter for Bachiaria decumbens and in adittion to the highest percentage of leaf among all treatments. On contrary, in the plot of Pinus tecunumanii, was observed the smallest monthly availability of dry matter and therefore smaller percentage of leaf. The second study was called of: Availability of biomass B. decumbens, in a silvopastoral system with eucalyptus: the role of radiation\" where the forestry component was the eucalyptus (COP-1377) with 2 years old planted in an area of 10 ha, divided in 3 treatments (long-OL wave (39 m), short-OC wave (21 m), and witness-T.) and instaled into 4 distinct blocks. Two samples were taken during the summer and winter period, where was possible verify that the OL treatment result showed more availability of biomass to 65% of irradiance beyond a higher percentage of the leaf fraction. This was favored by the biggest spacing between the alleys. However, there was attack on the grassland by leafhoppers keeping the downfall of availability during the winter. The third study was entitled: \"Architectural variations of monoculture of E. urograndis according to their spatial position\" was also reld at the monoculture of the first study, in an area of 7 ha. For this study, there was held a forest inventory, right after, the trees were divided for his diametric class and it is selected randomly 60 trees for cubage, and of those, were chose 15 for the determination of biomass and wood density. For the obtaining of biomass the trees were divided in three analysis fractions: trunk, branches and leaf. In addition, the 15 trees were divided into: surround, intermediate and center of the plot, in accordance with the location. It was verified that the border presented the highest growth in DBH, height, crown wide and that consequently achieved greater volume and biomass in all the fractions. Also been possible to observ that either at border as center showed a higher basic density due to higher canopy and tree height encouraging the creation of more biomass leaf. Finally as the three studies conducted in this research work, it was concluded that solar irradiation is a key factor in the productivity of forage crop, demonstrating the necessity of more research on agroforestry and silvopastoral systems for the success of future property developments.

O presente estudo foi dividido em três capitulos, todos realizados na Estação Experimental de Ciências Florestais de Anhembi/SP, entre os anos de 2014 e 2015. O primeiro estudo intitulado de \"Variação mensal da fitomassa da forragem em função do grau de cobertura do dossel em sistemas silvipastoris\", foi realizado em 3 monoculturas de 13 anos de idade, com área útil de 50 m x 30 m para coleta de pasto as mesmas efectuadas mensalmente. Os resultados apresentaram que não há relação significativa entre a cobertura do dossel e fitomassa da forragem pelo caso de que o sub-bosque estava muito sombreado. Entretanto, houve uma relação indireta entre área basal e fitomassa. Evidenciando-se que o talhão de Eucalipto urograndis apresentou as melhores condições de crescimento e disponibilidade de materia seca mensal para Bachiaria decumbens além de obter a maior porcentagem de folha entre todos os tratamentos. Ao contrario, no talhão de Pinus tecunumanii, foi encontrada a menor disponibilidade de materia seca mensal e por consequência, menor porcentagem de folha. O segundo estudo foi chamado de: \"Disponibilidade de fitomassa de B. decumbens, em um sistema silvipastoril com eucalipto: o papel da radiação\" onde o componente florestal foi o eucalyptus (COP-1377) de 2 anos de idade plantado em uma área útil de 10 ha, dividido em 3 tratamentos (onda longa-OL (39 m), onda curta-OC (21 m), e testemunha-T) e instalado em 4 blocos distintos. Foram realizadas duas coletas dutante o período de verão e de inverno, onde foi possível verificar que o tratamento OL mostrou maior disponibilidade de fitomassa a 65% de irradiância além de obter maior porcentagem da fração folha. Este foi favorecido pelo maior espaçamento entre as aléias. Contudo, houve ataque de cigarinha na pastagem, mantendo a queda da disponibilidade no período de inverno. O terceiro estudo intitulado de: \"Variaçoes arquiteturais de uma monocultura de E. urograndis em função de sua posição espacial\", foi também realizado na monocultura do primeiro estudo, numa área de 7 ha. Para este estudo, realizou-se um inventario florestal, logo após, dividiu-se as árvores por sua classe diamétrica e selecionou-se aleatoriamente 60 árvores para cubagem, e destas, escolheu-se 15 para determinação da fitomassa e respectiva densidade da madeira. Para a obtenção da fitomassa dividiu-se as árvores em três frações de análise: tronco, galhos e folha. Além disso, as 15 árvores foram divididas em: bordadura, intermediária e centro da parcela, de acordo com a sua localização. Verificou-se que a bordadura apresentou os maiores crescimentos em DAP, altura, largura de copa e, que por consequência, obteve maior volume e fitomassa em todas suas frações. Também foi possível observar que tanto a bordadura quanto o centro apresentaram maior densidade básica em função da maior copa e altura das árvores incentivando a geração de mais fitomassa foliar. Finalmente conforme os três estudos realizados neste trabalho de pesquisa, concluiu-se que a radiação solar é fator chave na produtividade da cultura forrageira, demonstrando a necessidade de mais pesquisas sobre os sistemas agroforestais e silvipastoris para o sucesso de futuros emprendimentos. / This study was divided into three chapters, all of these were held in Forest Science Experiment Station of Anhembi / SP, between the years 2014 and 2015. The first study entitled of \"Monthly variation of biomass of forage due to the canopy cover degree in silvipastoral systems\" was fulfilled in 3 monocultures with 13 years of age, with useful area of 50 m x 30 m for pasture collecting the same month. The results showed no significant relationship between canopy cover and biomass of forage because of the shading of the understory. However, there was an indirect link between baseline and biomass area. Indicating that the that plot of Eucalyptus urograndis showed the best conditions of growth and availability of monthly dry matter for Bachiaria decumbens and in adittion to the highest percentage of leaf among all treatments. On contrary, in the plot of Pinus tecunumanii, was observed the smallest monthly availability of dry matter and therefore smaller percentage of leaf. The second study was called of: Availability of biomass B. decumbens, in a silvopastoral system with eucalyptus: the role of radiation\" where the forestry component was the eucalyptus (COP-1377) with 2 years old planted in an area of 10 ha, divided in 3 treatments (long-OL wave (39 m), short-OC wave (21 m), and witness-T.) and instaled into 4 distinct blocks. Two samples were taken during the summer and winter period, where was possible verify that the OL treatment result showed more availability of biomass to 65% of irradiance beyond a higher percentage of the leaf fraction. This was favored by the biggest spacing between the alleys. However, there was attack on the grassland by leafhoppers keeping the downfall of availability during the winter. The third study was entitled: \"Architectural variations of monoculture of E. urograndis according to their spatial position\" was also reld at the monoculture of the first study, in an area of 7 ha. For this study, there was held a forest inventory, right after, the trees were divided for his diametric class and it is selected randomly 60 trees for cubage, and of those, were chose 15 for the determination of biomass and wood density. For the obtaining of biomass the trees were divided in three analysis fractions: trunk, branches and leaf. In addition, the 15 trees were divided into: surround, intermediate and center of the plot, in accordance with the location. It was verified that the border presented the highest growth in DBH, height, crown wide and that consequently achieved greater volume and biomass in all the fractions. Also been possible to observ that either at border as center showed a higher basic density due to higher canopy and tree height encouraging the creation of more biomass leaf. Finally as the three studies conducted in this research work, it was concluded that solar irradiation is a key factor in the productivity of forage crop, demonstrating the necessity of more research on agroforestry and silvopastoral systems for the success of future property developments.

This work aimed to contribute to the understanding of tree - grass inter-cropping interactions so that the productivity and sustainability of extensive livestock husbandry can be increased. The work was carried out in the context of a small farm in Oaxaca, Mexico, where increases in productivity are limited by shortage of capital and where the tree component would be used as green manure. It is difficult to investigate the effectiveness of such a system by only using conventional field trials. I constructed a mathematical model to simulate how the main components of the system function under conditions that would not be evaluated in the field. Issues such as how many trees to plant and what tree species combine with grass cattle and environment, can be answered with the model. The particular features of the model are: 1) It describes an agro-ecosystem where trees perform several biological functions like nitrogen capture for use in the silvopastoral system, 2) It links grass and trees with the animal and 3) Nutrient availability depends mainly on soil organic matter decomposition and mineralisation rather than on external inputs. The present research consisted of 1) constructing the model prototype using data from the literature, 2) conducting field experiments to investigate the actual performance of the silvopastoral system, 3) perform laboratory research and greenhouse experiments complementarily to the field experiments and 4) elaborate on the carbon and nitrogen balance of the silvopastoral experiment, by combining research results and the mathematical model. The field experiment consisted of an array of 13 plots with one of the tree species Gliricidia sepium, Leucaena leucocephala, Delonix regia and Lysiloma auritum in a gradient of plant densities within a Brachiaria decumbens paddock. Results showed that the presence of trees in pastures is potentially useful for retaining nitrogen and carbon that would be lost in the grass mono-crop. Trees did not incorporate nitrogen through biological fixation, perhaps because the lack of adequate nodulation and they did not established their rooting systems to a depth beyond the grass roots (> 1.20m) so as to recover leached nutrients. However, trees produced mulch that was rich in nitrogen (3.8%) and whose decomposition rate ensures a slow release to prevent leaching. At the plant density used, the tree population caused no harm to grass as to production and nutritive value. Further increments in tree density in order to improve the potential for nitrogen capture should be evaluated in terms of the reduction of grass production. Several biological attributes of the species were determined, in some cases for the first time: biomass productivity, specific leaf area, nutritive value, phenolic content, root biomass, grass root longevity, root vertical distribution, etc. Such characterisation is useful for the understanding of the system inter-cropping and specially for the parameterisation of the silvopastoral model. Even though the mixtures proved able to survive for the span of the experiment, the sustainability of tree - grass inter-cropping as to the stabilisation of soil fertility requires longer monitoring. Other limiting factors such as phosphorus availability and the management of grazing systems have to be incorporated for an adequate evaluation of the silvopastoral system.

Orientador: Cristiana Andrighetto / Resumo: O objetivo deste trabalho foi avaliar a produção, valor nutritivo e capacidade de suporte do capim Marandu, desempenho produtivo e comportamento ingestivo de novilhas meio sangue Angus x Nelore. O experimento foi conduzido na APTA – Andradina, SP em Sistemas Silvipastoris, sendo: SSP-1 com 187 árvores/ha, SSP-2 com 446 árvores/ha, associado ao Eucalyptus urograndis, clone I-224 (17 e 18,7m de altura respectivamente) e Sistema Convencional (SC), ambos em pastagens de Urochloa brizantha cv. Marandu. Para as avaliações da forragem, foram realizadas: massa seca total, análise bromatológica, desempenho animal e taxa de lotação nas estações inverno e verão. Para o comportamento ingestivo, realizou-se quatro coletas: uma no início e outra no final das estações inverno e verão. Foram observados os seguintes comportamentos: pastejo, ruminação (em pé e deitado), ócio (em pé e deitado), outras atividades, que incluem: interação com outros animais, ida ao bebedouro e ao cocho, urinar e defecar e deslocamento. Concomitantemente, foram avaliados as seguintes variáveis microclimáticas: temperatura de globo negro, temperatura ambiente, umidade relativa do ar e velocidade do vento. A partir destes dados, foram calculados os seguintes índices de conforto térmico: índice de temperatura e umidade (ITU), índice de temperatura de globo e umidade (ITGU) e carga térmica radiante (CTR). O delineamento experimental foi em blocos completos com 3 tratamentos e 4 repetições. Os dados foram submetidos às ... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre

Submitted by (edna.saturno@ufrpe.br) on 2017-04-20T16:47:29Z No. of bitstreams: 1 Izabela Aline Gomes da Silva.pdf: 1675799 bytes, checksum: 9dff763f7593bc008e56d2342bc2feca (MD5) / Made available in DSpace on 2017-04-20T16:47:29Z (GMT). No. of bitstreams: 1 Izabela Aline Gomes da Silva.pdf: 1675799 bytes, checksum: 9dff763f7593bc008e56d2342bc2feca (MD5) Previous issue date: 2015-07-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Studying about litter dynamics in silvopastoral systems is critical to estimate the natural return of nutrients to the soil and reduce the use of nitrogen fertilizers. This research evaluated litter deposition, litter decomposition, and nitrogen contents of gliricidia [Gliricidia sepium (Jacq.) Kunth ex Walp.] and sabia (Mimosa caesalpiniifolia Benth) intercropped with signal grass (Brachiaria decumbens Stapff.). The research was performed at the experimental research station of Itambe, conducted in the Agronomic Institute of Pernambuco (IPA).The randomized block design with a split plot arrangement was used. The main plots were the legumes intercropped with to grass and the subplots were the distances from the trees trunk. Senescent material was collected manually in a wood gatherers of 0.25m2 every month, in a perpendicular transect across the tree rows (between the tree rows, 2.0 m and 4.0 m away from the trees rows), during one year. The material collected was dried in a forced circulation oven for 72 h at 55°C, and later separated into four fractions (leaf, stem, reproductive structures and unrecognized), and weighed to determine the dry biomass, then the contents were milled in a grinder type Willey with 1 mm sieve for analysis of nitrogen content. Litter decomposition was evaluated by litter bag technique with a mesh of 75 μm and litter samples were collected from both species and incubated for 0, 4, 8, 16, 32, 64, 128 and 256 days. The bags were incubated in the same spots of wood gatherers. The litterbags were collected and dried in a forced circulation oven for 72 h at 55°C. The remaining material was used to determine N concentration. The annual deposition of litter fractions (leaves + branches + reproductive structures) between the rows of trees, two meters and four meters of rows of trees by sabia was (18,170 kg OM ha-1, 9,200 kg OM ha-1 OM and 4,200 kg ha-1) and by gliricidia (11,000 kg ha-1 OM, 2,480 kg OM ha-1 and 1,160 kg ha-1 OM). The annual contribution of these fractions in the three distances was 610 kg ha-1 of N by sabia and 450 kg ha-1 of N by gliricidia. For both legumes, the sheet fraction dominated entire contents of the litter, followed by the fraction branches, reproductive structures and unidentifiable structures. The annual deposit by unrecognized structures in the three respective distances, by sabia was (445 kg OM ha-1, 245 kg OM ha-1 and 90 kg OM ha-1) and by gliricidia (180 kg OM ha-1, 90 kg OM ha-1 and 45 kg OM ha-1). It was not quantified the nitrogen supply to these fractions. The sabia deposited larger amounts of litter in the months with less rainfall. The gliricidia litter deposition was not influenced by rain. The decomposition rates was greater to sabia (k=0,0055 g.g-1.dia-1) than gliricidia (k=0,0022 g.g-1.dia-1). The nitrogen mineralization to sabia was 77% and to gliricidia it was 50% leading a system contribution of 50 kg de N e 64 kg de N, respectively, during 256 days. The nitrogen from legume's litter is an important alternative to reduce chemical nitrogen use. / Estudar sobre a dinâmica de serrapilheira em sistemas silvipastoris é fundamental para estimar o retorno de nutrientes ao solo e diminuir o uso de fertilizantes nitrogenados. Dessa forma, objetivou-se avaliar a deposição, decomposição e teores de nitrogênio das serrapilheiras de sabiá (Mimosa caesalpiniifolia Benth) e gliricídia (Gliricidia sepium (Jack) Kunth ex Walp) em pastagens consorciadas com Brachiaria decumbens Stapff. O experimento foi conduzido na Estação Experimental pertencente ao Instituto Agronômico de Pernambuco-IPA, Itambé-PE. Foi utilizado o delineamento em blocos ao acaso com arranjo em parcelas subdivididas. As parcelas principais foram as duas leguminosas consorciadas com a gramínea, e as subparcelas foram as três distâncias das fileiras das árvores. A deposição de serrapilheira foi avaliada pelo uso de coletores de madeira que foram distribuídos entre as fileiras duplas das leguminosas, a dois e a quatro metros destas fileiras. O material depositado mensalmente durante um ano foi colocado em estufa a 55˚C por 72 horas, separado em quatro frações (folhas, ramos, estruturas reprodutivas e estruturas não identificáveis), e pesado para determinar a biomassa seca. O conteúdo foi triturado em moinho tipo Willey com peneira de 1mm para quantificar o aporte de nitrogênio depositado por cada fração nas três distâncias das fileiras das árvores. A avaliação da taxa de decomposição foi feita pela análise do desaparecimento de massa ao longo do tempo. Foram utilizados sacos de náilon 100% poliéster com 75 micrômetros de porosidade. As amostras de ambas as espécies de serrapilheira foram coletadas e incubadas durante 0, 4, 8, 16, 32, 64, 128 e 256 dias. Os sacos foram incubados nos mesmos pontos dos coletores de madeira. Após coleta, os sacos foram pré-secos em estufa a 55˚C por 72 horas. As concentrações de nitrogênio remanescente foram calculadas para serrapilheira retirada dos sacos após cada tempo de incubação. A deposição anual das frações de serrapilheira (folhas+ramos+estruturas reprodutivas) entre as fileiras das árvores, a dois metros e a quatro metros das fileiras das árvores para sabiá foi de (18.170kg MO ha-1, 9.200 kg MO ha-1 e 4.200 kg MO ha-1) e para a gliricídia (11.000 kg MO ha1, 2.480 kg MO ha-1 e 1.160 kg MO ha-1). O aporte anual dessas frações nas três distâncias foi de 610 kg ha-1 de N para sabiá e 450 kg ha-1 de N para a gliricídia. Para ambas as leguminosas, a fração folha dominou conteúdo total da serrapilheira, seguida da fração ramos, estruturas reprodutivas e estruturas não identificáveis. O depósito anual de estruturas não identificáveis nas três respectivas distâncias, para a sabiá foi de (445 kg MO ha-1, 245 kg MO ha-1 e 90 kg MO ha-1) e para a gliricídia de (180 kg MO ha-1, 90 kg MO ha-1 e 45 kg MO ha-1). Não foi quantificado o aporte de nitrogênio para essas frações. A sabiá depositou maiores quantidades de serrapilheira nos meses com menores precipitações pluviais. A deposição de serrapilheira de gliricídia não foi influenciada pelas chuvas. A taxa de decomposição para a sabiá (k=0,0055 g.g-1.dia-1), também foi maior que para a gliricídia (k = 0,0022 g.g-1.dia-1). A mineralização de N na serrapilheira de sabiá foi de 77% e da gliricídia foi de 50% proporcionando um aporte de 50 kg de N e 64 kg de N, respectivamente, durante os 256 dias. O maior porcentual de nitrogênio nas folhas e ramos de gliricídia contribuiu com o maior aporte desse nutriente. A contribuição de nitrogênio pelas serrapilheiras das leguminosas avaliadas representa uma importante alternativa para redução do uso de nitrogênio químico

Este trabalho objetivou realizar a avaliação econômica comparativa entre as seguintes atividades na região sudoeste paulista: ovinocultura de corte, monocultura de eucalipto visando produção de madeira para celulose e dois modelos de sistema silvipastoril (SSP) composto por clones de eucalipto, pastagem pré-existente e ovinos para o módulo de 30 ha e horizonte de sete anos. Os SSP avaliados possuíam espaçamento 12 x 1 m (SSP I) e 2 x 2 x 12 m (SSP II). Os critérios econômicos utilizados foram o Valor Presente Líquido (VPL) à taxa de desconto de 8 % a.a. e a Taxa Interna de Retorno (TIR). As avaliações econômicas foram realizadas sob condições de risco utilizando-se a simulação Monte Carlo para as variáveis aleatórias consideradas mais relevantes do fluxo de caixa de cada atividade. Para realizar a avaliação econômica da ovinocultura foi necessário primeiramente caracterizar o sistema de produção ovina para a região de estudo mediante visitas técnicas às propriedades pertencentes ao Núcleo Sul Paulista de ovinocultores utilizando-se um questionário semi-estruturado. Na atividade ovina foram consideradas variáveis aleatórias a \"taxa de concepção das ovelhas, taxa de mortalidade dos cordeiros com até 60 dias de idade e taxa de reposição do rebanho\". Admitiu-se para as variáveis mencionadas a distribuição triangular. Na atividade florestal foram consideradas variáveis aleatórias as operações mecanizadas e manuais necessárias para a implantação e manutenção da cultura do eucalipto em espaçamento 3 x 2 m, coletadas da base de dados de uma empresa prestadora de serviços florestais da região. Foi analisado um total de 8.225 informações de implantação e tratos culturais (manutenções) permitindo constituir dois cenários: mecanizado e manual. Dezessete operações foram utilizadas e o rendimento operacional, suas distribuições de probabilidade e parâmetros foram determinados. Para as avaliações dos SSP foram utilizadas as variáveis aleatórias mencionadas de cada atividade, porém, no caso das variáveis aleatórias da atividade florestal, os rendimentos operacionais foram calculados proporcionalmente aos espaçamentos praticados. A análise Monte Carlo considerou 10.000 simulações e foi desenvolvida com o apoio do software @risk. O VPL médio da ovinocultura foi de R$ 2.618,35 para o módulo de 30 hectares e tem elevado desvio padrão, R$ 41.061,86. A TIR dessa atividade apresentou valor de 29,31 % a.a, porém também com desvio padrão elevado (27,70 %). A monocultura de eucalipto apresentou valores médios de VPL positivos para o cenário mecanizado e manual, correspondendo a R$ 71.963,42/30 ha e R$ 73.123,66/30 ha, respectivamente e TIR média superiores à taxa de desconto praticada nesse estudo, 15,58 % a.a. e 15,97 % a.a., respectivamente. O SSP I e o SSP II são economicamente viáveis, apresentando VPL médios de R$ 85.032,45 e R$ 69.521,20 e TIR média de 21,03 e 19,18 %, respectivamente. De acordo com o critério do VPL a atividade mais rentável é o SSP I, seguido pela monocultura de eucalipto (cenário manual e mecanizado, respectivamente), SSP II e ovinocultura. Segundo o critério da TIR a ovinocultura apresenta-se como a atividade mais viável, seguido pelo SSP I, SSP II e a monocultura de eucalipto (cenário manual e mecanizado, respectivamente). / This study aimed to perform an economic evaluation comparing the following activities in the southwestern region of São Paulo state: beef cattle sheep, eucalypt monoculture for pulpwood production and two models of silvopastoral system (SSP) composed of eucalypt clones, natural pasture and sheep to a module of 30 ha and a seven-year cycle. The SSP assessed had a 12 x 1 m spacing (SSP I) and 2 x 2 x 12 m (SSP II). The economic criteria used were the Net Present Value (NPV) at 8% interest rate and the Internal Rate of Return (IRR). The economic evaluations were performed under risk conditions using Monte Carlo simulation for the random variables considered most relevant for each activity´s cash flow. In order to perform an economic evaluation of cattle production it was first necessary to characterize the sheep production system for the study area through technical visits to properties belonging to the \"Núcleo Sul Paulista\" of sheep breeders using a semi-structured questionnaire. In the ovine activity variables random to \"conception rate of ewes, lambs mortality rate of up to 60 days of age and replacement rate of flock\" were considered. Triangular distribution was admitted to the mentioned variables. In forestry, mechanized and manual operations necessary for the implementation and maintenance of eucalypt plantation of 3 x 2 m spacing were considered random variables, collected from the data base of a forestry services company from the region. A total of 8,225 field information data on implantation and cultivation (maintenance) were analyzed, allowing the constitution of a mechanized and a manual scenario. Seventeen operations were used and the operational income, its probability distributions and parameters were determined. Random variables listed for each activity were used for the evaluation of SSP, however, in random variables of forestry activity, the operational earnings were calculated in proportion to the spacing practiced. The Monte Carlo analysis considered 10,000 simulations and was developed with the support of @ risk software. The average NPV of ovine culture was R$ 2,618.35 for the 30-hectare modulus and has a high standard deviation, R$ 41,061.86. IRR for this activity showed a value of 29.31%, but also with a high standard deviation (27.70%). The eucalypt monoculture showed average values of NPV, positive for both mechanized and manual scenarios, corresponding to R$ 71,963.42 / 30 ha and R$ 73,123.66 / 30 ha, respectively, and average IRR superior to the interest rate practiced in this study, 15.58% and 15.97% respectively. SSP I and SSP II are economically viable, with average NPV of R$ 85,032.45 and R$ 69,521.20 and average IRR of 21.03 and 19.18%, respectively. According to the NPV criteria, SSPI proved to be the most profitable activity, followed by eucalypt monoculture (manual and mechanized scenarios, respectively), SSP II and ovine culture. As determined by IRR criteria, cattle production presents itself as the most viable activity, followed by SSP I, SSP II and eucalypt monoculture (manual and mechanized scenarios, respectively).

Este trabalho objetivou realizar a avaliação econômica comparativa entre as seguintes atividades na região sudoeste paulista: ovinocultura de corte, monocultura de eucalipto visando produção de madeira para celulose e dois modelos de sistema silvipastoril (SSP) composto por clones de eucalipto, pastagem pré-existente e ovinos para o módulo de 30 ha e horizonte de sete anos. Os SSP avaliados possuíam espaçamento 12 x 1 m (SSP I) e 2 x 2 x 12 m (SSP II). Os critérios econômicos utilizados foram o Valor Presente Líquido (VPL) à taxa de desconto de 8 % a.a. e a Taxa Interna de Retorno (TIR). As avaliações econômicas foram realizadas sob condições de risco utilizando-se a simulação Monte Carlo para as variáveis aleatórias consideradas mais relevantes do fluxo de caixa de cada atividade. Para realizar a avaliação econômica da ovinocultura foi necessário primeiramente caracterizar o sistema de produção ovina para a região de estudo mediante visitas técnicas às propriedades pertencentes ao Núcleo Sul Paulista de ovinocultores utilizando-se um questionário semi-estruturado. Na atividade ovina foram consideradas variáveis aleatórias a \"taxa de concepção das ovelhas, taxa de mortalidade dos cordeiros com até 60 dias de idade e taxa de reposição do rebanho\". Admitiu-se para as variáveis mencionadas a distribuição triangular. Na atividade florestal foram consideradas variáveis aleatórias as operações mecanizadas e manuais necessárias para a implantação e manutenção da cultura do eucalipto em espaçamento 3 x 2 m, coletadas da base de dados de uma empresa prestadora de serviços florestais da região. Foi analisado um total de 8.225 informações de implantação e tratos culturais (manutenções) permitindo constituir dois cenários: mecanizado e manual. Dezessete operações foram utilizadas e o rendimento operacional, suas distribuições de probabilidade e parâmetros foram determinados. Para as avaliações dos SSP foram utilizadas as variáveis aleatórias mencionadas de cada atividade, porém, no caso das variáveis aleatórias da atividade florestal, os rendimentos operacionais foram calculados proporcionalmente aos espaçamentos praticados. A análise Monte Carlo considerou 10.000 simulações e foi desenvolvida com o apoio do software @risk. O VPL médio da ovinocultura foi de R$ 2.618,35 para o módulo de 30 hectares e tem elevado desvio padrão, R$ 41.061,86. A TIR dessa atividade apresentou valor de 29,31 % a.a, porém também com desvio padrão elevado (27,70 %). A monocultura de eucalipto apresentou valores médios de VPL positivos para o cenário mecanizado e manual, correspondendo a R$ 71.963,42/30 ha e R$ 73.123,66/30 ha, respectivamente e TIR média superiores à taxa de desconto praticada nesse estudo, 15,58 % a.a. e 15,97 % a.a., respectivamente. O SSP I e o SSP II são economicamente viáveis, apresentando VPL médios de R$ 85.032,45 e R$ 69.521,20 e TIR média de 21,03 e 19,18 %, respectivamente. De acordo com o critério do VPL a atividade mais rentável é o SSP I, seguido pela monocultura de eucalipto (cenário manual e mecanizado, respectivamente), SSP II e ovinocultura. Segundo o critério da TIR a ovinocultura apresenta-se como a atividade mais viável, seguido pelo SSP I, SSP II e a monocultura de eucalipto (cenário manual e mecanizado, respectivamente). / This study aimed to perform an economic evaluation comparing the following activities in the southwestern region of São Paulo state: beef cattle sheep, eucalypt monoculture for pulpwood production and two models of silvopastoral system (SSP) composed of eucalypt clones, natural pasture and sheep to a module of 30 ha and a seven-year cycle. The SSP assessed had a 12 x 1 m spacing (SSP I) and 2 x 2 x 12 m (SSP II). The economic criteria used were the Net Present Value (NPV) at 8% interest rate and the Internal Rate of Return (IRR). The economic evaluations were performed under risk conditions using Monte Carlo simulation for the random variables considered most relevant for each activity´s cash flow. In order to perform an economic evaluation of cattle production it was first necessary to characterize the sheep production system for the study area through technical visits to properties belonging to the \"Núcleo Sul Paulista\" of sheep breeders using a semi-structured questionnaire. In the ovine activity variables random to \"conception rate of ewes, lambs mortality rate of up to 60 days of age and replacement rate of flock\" were considered. Triangular distribution was admitted to the mentioned variables. In forestry, mechanized and manual operations necessary for the implementation and maintenance of eucalypt plantation of 3 x 2 m spacing were considered random variables, collected from the data base of a forestry services company from the region. A total of 8,225 field information data on implantation and cultivation (maintenance) were analyzed, allowing the constitution of a mechanized and a manual scenario. Seventeen operations were used and the operational income, its probability distributions and parameters were determined. Random variables listed for each activity were used for the evaluation of SSP, however, in random variables of forestry activity, the operational earnings were calculated in proportion to the spacing practiced. The Monte Carlo analysis considered 10,000 simulations and was developed with the support of @ risk software. The average NPV of ovine culture was R$ 2,618.35 for the 30-hectare modulus and has a high standard deviation, R$ 41,061.86. IRR for this activity showed a value of 29.31%, but also with a high standard deviation (27.70%). The eucalypt monoculture showed average values of NPV, positive for both mechanized and manual scenarios, corresponding to R$ 71,963.42 / 30 ha and R$ 73,123.66 / 30 ha, respectively, and average IRR superior to the interest rate practiced in this study, 15.58% and 15.97% respectively. SSP I and SSP II are economically viable, with average NPV of R$ 85,032.45 and R$ 69,521.20 and average IRR of 21.03 and 19.18%, respectively. According to the NPV criteria, SSPI proved to be the most profitable activity, followed by eucalypt monoculture (manual and mechanized scenarios, respectively), SSP II and ovine culture. As determined by IRR criteria, cattle production presents itself as the most viable activity, followed by SSP I, SSP II and eucalypt monoculture (manual and mechanized scenarios, respectively).

The general goal of this research was to understand the agronomic and physiological changes of a lucerne crop in distinct physical radiation environments and to verify the potential of lucerne to grow under shaded conditions. To achieve this, the research was conducted in four main steps: (i) firstly, experimental data collection in the field using two artificial shade materials (shade cloth and wooden slats) under inigated and non-irrigated conditions; (ii) a second experiment with data collection in a typical temperate dryland agroforestry area under non-irrigated conditions; (iii) generation of a light interception sub-model suitable for shaded crops and (iv) a linkage between the light interception sub-model and a canopy photosynthesis model for agroforestry use. In experiments 1 and 2, lucerne crop was exposed to 6 different light regimes: full sunlight (FS), shade cloth (FS+CL), wooden slats (FS+SL), trees (T), trees+cloth (T +CL) and trees+slats (T+SL). The FS+SL structure produced a physical radiation environment (radiation transmission, radiation periodicity and spectral composition) that was similar to that observed in the agroforestry site (f). The mean annual photosynthetic photon flux density (PPFD) was 41 % under the FS+CL, 44% under FS+SL and 48% under T compared with FS in clear sky conditions. Plants were exposed to an intermittent (sun/shade) regime under both FS+SL and T, whereas under FS+CL the shaded light regime was continuous. The red to far-red (RIFR) ratio measured during the shade period under the slats was 0.74 and under the trees was 0.64. However, R/FR ratio increased to 1.26 and 1.23 during the illuminated period under FS+SL and T, respectively, and these were equivalent to the ratio of 1.28 observed under the FS+CL and 1.31 in FS. The radiation use efficiency (RUE) of shoots increased under the 5 shaded treatments compared with full sunlight. The pattern of radiation interception was unchanged by radiation flux, periodicity and spectral composition and all treatments had a mean extinction coefficient of 0.82. However, the magnitude of the decrease in canopy growth was less than those in PPFD transmissivity. The mean lucerne annual dry matter (DM) yield was 17.5 t ha⁻¹ in FS and 10 t ha⁻¹ under the FS+CL, FS+SL and T regimes. This declined to 3.4 t DM ha⁻¹ under T+CL (22% PPFD transmissvity) and 4.1 t DM ha⁻¹ under T+SL (23% transmissivity). A similar pattern of response was observed for leaf net photosynthesis (Pn) rates under the shade treatments compared with full sun. In addition, spectral changes observed under the trees and slats affected plant motphology by increasing the number of long stems, stem height and internode length compared with full sunlight. Thus, there were two main explanations for the increase in RUE under shade compared with full sun: (i) preferential partition of assimilates to shoot rather than root growth and/or (ii) leaves under shade were still operating at an efficient part of the photosynthetic light curve. The changes proposed for the canopy Pn model were appropriate to simulate the radiation environment of an agroforestry system. However, the model underestimated DM yields under the continuous and intermittent shade regimes. These were considered to be mainly associated with plant factors, such as overestimation in maintenance respiration and partitioning between shoots and roots in shade and the intermittency light effect on leaf Pn rates. Further investigation in these topics must be addressed to accurately predict crop yield in agroforestry areas. Overall, the lucerne crop responded typically as a sun-adapted plant under shade. It was concluded that lucerne yield potential to grow under intermediate shade was superior to most of C3 pastures previously promoted in the literature.

The general goal of this research was to understand the agronomic and physiological changes of a lucerne crop in distinct physical radiation environments and to verify the potential of lucerne to grow under shaded conditions. To achieve this, the research was conducted in four main steps: (i) firstly, experimental data collection in the field using two artificial shade materials (shade cloth and wooden slats) under inigated and non-irrigated conditions; (ii) a second experiment with data collection in a typical temperate dryland agroforestry area under non-irrigated conditions; (iii) generation of a light interception sub-model suitable for shaded crops and (iv) a linkage between the light interception sub-model and a canopy photosynthesis model for agroforestry use. In experiments 1 and 2, lucerne crop was exposed to 6 different light regimes: full sunlight (FS), shade cloth (FS+CL), wooden slats (FS+SL), trees (T), trees+cloth (T +CL) and trees+slats (T+SL). The FS+SL structure produced a physical radiation environment (radiation transmission, radiation periodicity and spectral composition) that was similar to that observed in the agroforestry site (f). The mean annual photosynthetic photon flux density (PPFD) was 41 % under the FS+CL, 44% under FS+SL and 48% under T compared with FS in clear sky conditions. Plants were exposed to an intermittent (sun/shade) regime under both FS+SL and T, whereas under FS+CL the shaded light regime was continuous. The red to far-red (RIFR) ratio measured during the shade period under the slats was 0.74 and under the trees was 0.64. However, R/FR ratio increased to 1.26 and 1.23 during the illuminated period under FS+SL and T, respectively, and these were equivalent to the ratio of 1.28 observed under the FS+CL and 1.31 in FS. The radiation use efficiency (RUE) of shoots increased under the 5 shaded treatments compared with full sunlight. The pattern of radiation interception was unchanged by radiation flux, periodicity and spectral composition and all treatments had a mean extinction coefficient of 0.82. However, the magnitude of the decrease in canopy growth was less than those in PPFD transmissivity. The mean lucerne annual dry matter (DM) yield was 17.5 t ha⁻¹ in FS and 10 t ha⁻¹ under the FS+CL, FS+SL and T regimes. This declined to 3.4 t DM ha⁻¹ under T+CL (22% PPFD transmissvity) and 4.1 t DM ha⁻¹ under T+SL (23% transmissivity). A similar pattern of response was observed for leaf net photosynthesis (Pn) rates under the shade treatments compared with full sun. In addition, spectral changes observed under the trees and slats affected plant motphology by increasing the number of long stems, stem height and internode length compared with full sunlight. Thus, there were two main explanations for the increase in RUE under shade compared with full sun: (i) preferential partition of assimilates to shoot rather than root growth and/or (ii) leaves under shade were still operating at an efficient part of the photosynthetic light curve. The changes proposed for the canopy Pn model were appropriate to simulate the radiation environment of an agroforestry system. However, the model underestimated DM yields under the continuous and intermittent shade regimes. These were considered to be mainly associated with plant factors, such as overestimation in maintenance respiration and partitioning between shoots and roots in shade and the intermittency light effect on leaf Pn rates. Further investigation in these topics must be addressed to accurately predict crop yield in agroforestry areas. Overall, the lucerne crop responded typically as a sun-adapted plant under shade. It was concluded that lucerne yield potential to grow under intermediate shade was superior to most of C3 pastures previously promoted in the literature.