Objetivou-se com este estudo avaliar o efeito de preparos de solo diferenciados, aplicados em duas bacias hidrográficas experimentais reflorestadas com eucalipto, sobre o balanço hídrico, o escoamento direto, a qualidade da água, a ciclagem de nutrientes e as perdas de solo. As microbacias estão localizadas no Vale do Paraíba, Município de Santa Branca, Estado de São Paulo. Fazem parte da Fazenda Bela Vista III, que pertence à empresa FLORIN - Florestamento Integrado S.A. A microbacia A tem uma área de 7,2 ha, sendo 239 m2 (3,3% da área) de mata ciliar, com uma declividade média de 19, 6%; enquanto a área da microbacia B é de 5,5 ha, com 117 m2 (2,1% da área) de mata ciliar e a declividade média de 28,9%. As duas áreas foram plantadas com Eucalyptus saligna Smith, porém tiveram preparos de solo diferenciados: na microbacia A, o preparo de solo consistiu em roçada, queimada, e aração a 20 cm de profundidade com arado de disco; na microbacia B, o preparo de solo consistiu apenas em roçada, queimada, e coveamento manual. As microbacias tiveram as matas ciliares preservadas. A precipitação foi medida com um pluviógrafo tipo Helmann, de rotação semanal, que propiciou a tabulação dos dados de precipitacão diária, para as duas microbacias, três pluviômetros tipo Ville de Paris e um pluviômetro de acrílico marca Fretin, que contituiram a rede para a determinação, pela média aritmética, da precipitação semanal para as bacias. Para a amostragem de água das chuvas visando as análises físico-químicas foram instalados cinco coletores apropriados ao longo das duas microbacias. O deflúvio das microbacias foi obtido através da medição contínua da vazão, sendo utilizados dois linígrafos modelo Hidrologia, instalados um em cada estação fluviométrica. As amostras do deflúvio, em ambas microbacias, foram coletadas no vertedouro, com garrafas de polietileno, em intervalos semanais. As determinações dos elementos K+, Ca++ , Mg++, Fe++ e Na+, como parte da análise da água da chuva e do deflúvio, foram realizadas por meio de espectrofotômetro de absorção atômica. O N03- e P04-3 foram analisados por colorimetria, pelos métodos da brucina e do fosfomolibdato, respectivamente . O NH4+ foi determinado por titulação pelo método da destilação. Seguindo-se as normas da AMERICAN PUBLIC HEALTH ASSOCIATION (1976), foram realizadas as análises de turbidez, condutividade elétrica e pH. Os valores da alcalinidade foram obtidos por titulação, e os valores de cor, por colorimetria, tendo-se como escala colorimétrica uma solução de platino-cobalto. A perda de solo foi calculada a partir da concentração semanal de sedimento, mais aquelas oriundas de chuvas isoladas. O material sedimentado, por ter se mostrado em muita pequena quantidade e de difícil quantificação, não foi mensurado. No entanto, acredita-se que a sua ausência na totalização da perda de solo não interfira, de forma significativa, na análise da comparação relativa das perdas de solo entre as duas microbacias estudadas. A microbacia B apresenta condições que favorecem o escoamento superficial, possibilitando a existência de áreas passiveis de erosão e formação de voçorocas. Já a microbacia A possui condições mais permeáveis do solo, as quais favorecem o escoamento subsuperficial. A evapotranspiração para a microbacia A foi de 82,8%, enquanto a microbacia B, durante o período estudado, mostrou uma taxa de 44,4%. Os fluxos mensais de nutrientes mostraram que existe um ganho de NH4+, NO3- e PO4-3 para ambas microbacias. O Ca++, Mg++, Fe++ e o Na+ apresentaram um balanço negativo . Já o K+ revelou um ganho na microbacia A, ao contrário da microbacia B. A contribuição relativa da precipitação ocorrida na área experimental em relação ao teor de nutrientes contidos numa árvore inteira, num tronco com casca e noutro sem casca, mostrou que a entrada de nitrogênio via precipitação foi significativa, enquanto as entradas de P04-3, K+, Ca++ e Mg++ estiveram abaixo do requerido, principalmente, se a exploração da árvore inteira for considerada. A produção de sedimento em suspensão foi 2,5 vezes maior na microbacia B do que na microbacia A. Já a contribuição média devida às chuvas, nas perdas totais de solo da microbacia A atingiu apenas 4,89%; na microbacia B esta contribuição chegou a 40,56%. As medidas de preparo de solo e de cultivo mínimo, baseados na declividade média do terreno e na textura de solo; além da preservação das matas ciliares, adotadas previamente pela empresa, estão, aparentemente, sendo eficientes na conservação do solo, conforme os dados analisados no presente estudo. / The goal of this study is to estimate the effects of different managements applied to two experimental catchments with eucalypt plantations over the water balance, the nutrient cycling and the soil loss. The small catchments are located in Paraíba River Valley, in the Municipatily of Santa Branca, São Paulo State. They are part of III Bela Vista Forest Farm, from FLORIN - Integrated Forested company S. A. The A catchment has an area of 7.2 ha, with an average slope of 19.6%, while the area of the B catchment is 5.5 ha, and its average slope is 28.9%. Both areas were planted with Eucalyptus saligna Smith, but they had different site preparation: at catchment A, the plantation was preceded by a mechanical method of site preparation (plowing without harrowing); at catchment B. the plantation was established manually without soil preparation (slash burning). The small catchment the had riparian ecosystem preserved. The precipitation was measured with a Helmann type recording gage, with a week rotation, and four non-recording raingages. Average by arithmetic mean precipitation for the catchments was determined. Five adequate collectors were installed for the rainfall sampling aiming at the physical-chemical analysis. Streamflow was measured with 90° V-notch weirs containing a stage recorders installed one in each gaging station. The streamflow samples, in both small catchments, were collect weekly at the weir with polyethylene bottles. The determinations of K+, Ca++, Mg++, Fe++ and Na+ elements, as part of the rainfall and of the streamflow analysis, were made by spectrophotometry. N03- and P04-3 were analysed by colorimetry, using the brucina and phosphomolybdate methods, respectively. The NH4+ was analyzed by the distillation method. The loss of soil was calculated from the weekly sediment concentration. Additionally, the weirs were adapted with a semi-automatic sampling device to collect samples from higher stage to storm discharge. The sedimented material, being very tiny and in small quantity, was not measured. However, we believe that the absence at this part in the totalization of soil loss does not interfere in an essencial way in the comparative analysis of the soil loss between the two catchments. Catchment B presents conditions that favors surface runoff, allowing the existence of possible areas of erosion and gully formation. But catchment A has more permeable soil, which are favourable to the subsurface runoff. Evapotranspiration was 82.8% of the annual precipitation in catchment A, while for catchment B this percentage was 44.4%. The monthly flows of nutrients showed a gain of NH4+, N03- and P04-3 in both catchments. For Ca++, Mg++, Fe++ and the Na+ the balance was negative. But for K+ there was a gain in catchment A, and a loss in catchment B. The relative contribution of nutrient input in precipitation measured in this experimental area, in comparison with the nutrient contents of a whole tree, a trunk with bark, and a trunk without bark, showed that the input of nitrogen by precipitation was significant, while the inputs of P04-3, K+, Ca++ and Mg++ were below required amount, mainly if the exploration of the whole tree was considered. The production of suspended sediment was 2.5 times greater in the catchment B than in catchment A. But the average contribution due to the rain, in the total loss of the soil in catchment A reached only 4.89%; in the catchment B this contribution reached 40.56%. The method of site preparation and minimal cultivation, besides the policy of preserving riparian ecosystem, used routinely by the company are apparently being confirmed as adequate for soil and water conservation in the region.

Made available in DSpace on 2017-07-25T19:30:45Z (GMT). No. of bitstreams: 1 Marcelo Ferreira Hupalo.pdf: 3727414 bytes, checksum: 09f9dfd825a705447a6096b342217638 (MD5) Previous issue date: 2013-12-12 / Tomato is the most important economic vegetable in Brazil. The state of Parana is a significant fresh market tomato grower, and the Reserva city is the largest grower in this state. The tomato crop is important to family based farm because it contribute to income and employ generation, however it has a high financial cost and highly demand of handling practices and cultivation. Among farming practices stands irrigation, which can influence the crop production and fruit quality. For environmental issues, thinking about conservation of soil and water, the irrigation practice should be performed properly. The no-tillage system is established in erosion control, reduction of soil temperature range and contamination reduction in water sources in grain crops. In vegetable crops, especially in tomato crop, this must be better studied. The aim of this study was to assess consumption of irrigation water, soil temperature range, quality of the harvested product, yield and efficiency of water use in the production of fresh market tomatoes in the Campos Gerais region according to the level of cover crop. The treatments were quantities of dry matter on the soil: T1 (no dry matter on the soil); T2 (3.09 Mg ha-1 of dry matter); T3 (5.03 Mg ha-1 of dry matter); T4 (7.17 Mg ha-1 of dry matter) and T5 (9.20 Mg ha-1 of dry matter). There was significant effect of different levels of dry matter on the irrigation water consumption, where the increase of dry matter promoted the reduction of irrigation depth (mm) applied ranging 17 to 30%. No-tillage system promoted, on average, savings of 20% of irrigation water applied when compared to conventional production system. The maximum and miminum temperatures and soil temperature range decreased with the increase of dry matter on the soil. The increase in dry matter on the soil promoted high yield of total marketable fruits and high yield of fruits from 3A and 1A classes. Moreover this decreased the proportion of non-marketable fruits with disruption and blossom-end rot. The maximum and minimum temperatures and the thermal amplitude of the soil were reduced with the increase of dry matter on ground. The increase of dry matter on the soil promoted greater total marketable fruit yield and maximum fruit yield of 3A and 1A classes. Furthermore, reduced the proportion of unmarketable fruits with blossom end rot and cracking. The increase of dry matter on the soil caused greater yield and total marketable fruit yield of 05 to 15%. / O tomate é a hortaliça de maior importância econômica no Brasil. O estado do Paraná é um expressivo produtor de tomate de mesa, sendo o município de Reserva o maior produtor estadual. A cultura do tomate é de grande importância para a agricultura de base familiar contribuindo para a geração de emprego e renda, entretanto, apresenta um elevado custo financeiro sendo exigente em manejo e tratos culturais. Entre as diversas práticas de manejo se destaca a irrigação, a qual pode influenciar a produção e qualidade dos frutos. Por questões ambientais, pensando em conservação de solo e água, a prática da irrigação deve ser realizada de maneira adequada. O sistema plantio direto na palha é consagrado no controle da erosão, redução da amplitude térmica do solo e redução da contaminação de mananciais na cultura de grãos. Nas hortaliças, em especial na cultura do tomate, este deve ser melhor estudado. O objetivo deste trabalho foi avaliar consumo de água de irrigação, variação da temperatura do solo, qualidade do produto colhido, produtividade e eficiência do uso da água na produção de tomate de mesa na região dos Campos Gerais conforme níveis de cobertura vegetal do solo. O delineamento experimental foi de blocos aleatorizados, com cinco tratamentos e cinco repetições. Os tratamentos foram quantidades de matéria seca de aveia preta sobre o solo: T1 (ausência de matéria seca); T2 (3,09 Mg ha-1); T3 (5,03 Mg ha-1); T4 (7,17 Mg ha-1) e T5 (9,20 Mg ha-1). Houve efeito significativo dos níveis de matéria seca sobre o consumo de água de irrigação, sendo que, com o incremento de matéria seca ocorreu decréscimo da lâmina de Irrigação (mm) aplicada variando de 17 a 30%. As temperaturas máximas e mínimas e a amplitude térmica do solo tiveram redução com o incremento de matéria seca sobre solo. O incremento de matéria seca sobre o solo promoveu maior produtividade de frutos comercializáveis totais e maior produtividade de frutos das classes 3A e 1A. Além disso, reduziu a proporção de frutos não comercializáveis com rachaduras e com podridão apical. O incremento de matéria seca ao solo promoveu maior produtividade e rendimento de frutos comercializáveis totais de 5 a 15 %.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2014-10-14T14:46:29Z No. of bitstreams: 2 Tese - Idelfonso Colares de Freitas - Agronomia.pdf: 1658368 bytes, checksum: 281951adbbc39fb163075382c1dc3798 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-10-17T21:40:37Z (GMT) No. of bitstreams: 2 Tese - Idelfonso Colares de Freitas - Agronomia.pdf: 1658368 bytes, checksum: 281951adbbc39fb163075382c1dc3798 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-17T21:40:37Z (GMT). No. of bitstreams: 2 Tese - Idelfonso Colares de Freitas - Agronomia.pdf: 1658368 bytes, checksum: 281951adbbc39fb163075382c1dc3798 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-06-10 / Based on the premise that the replacement of native forests by agroecosystems impacts the soil, were studied different forms of soil use compared to a fragment preserved forest. The study was conducted in an Entisol Quartzipsammentunder the family agriculture use for 22 years, managed under: SAF – Agroforestry system, PA - Pasture, RT - Slash and burn field and MA - Preserved forest. The management impacts on the soil were estimated by the changes in the accumulation and quality of the soil mulch and by the changes on the physical and chemical indicators of soil. The collect of soil mulch, the soil resistance to penetration, until 40 cm depth, and the collect of deformed and undeformed soil samples, for of physical and chemical analyzes, collected in seven repetitions for each system, layers 0-5, 5-10, 10-20 and 20-40 cm depths for two consecutive years and in two sampling periods (July 2010/2011 and January 2011/2012). The variables analyzed were: accumulation of soil mulch and its nutrient content, carbon stock on soil mulch and the soil, plant residue quality index, soil organic matter, soil acidity, exchangeable bases, cation exchange capacity, bases and aluminum saturation, strength penetration, bulk density, porosity and soil aggregation. The results showed that soil use with agroforestry system, even after 22 years of use, little differentiates itself from the preserved area. The conversion of forest in agroecosystems enhances the soil chemical properties and significantly reduces the stocked carbon in the soil mulch compartment, as noted in the “slash and burn” field. The soil use with pasture for successive years increases bulk density, strength penetration, microporosity and reduces soil macroporosity. In this study, clear distinctions between the forms of use and soil management were observed in stocks of litter on the soil surface and strength penetration. / Partindo da premissa que a substituição das florestas nativas por agroecossistemas impacta os solos, foram estudadas diferentes formas de uso do solo em comparação a um fragmento de floresta preservada. O estudo foi realizado em um Neossolo Quartzarênico sob uso da agricultura familiar por 22 anos, manejado sob: SAF – Sistema agroflorestal, PA – Pasto, RT – Roça de toco e MA – Mata preservada. Os impactos do manejo sobre o solo foram estimados por meio das mudanças ocorridas no acúmulo e qualidade da serrapilheira, indicadores físicos e químicos do solo. Coletas de serrapilheira, penetrometrias até 40 cm e amostras deformadas e indeformadas de solo, para fins de análises físicas e químicas, foram feitas em sete repetições por sistema de uso, nas camadas 0-5, 5-10, 10-20 e 20-40 cm, por dois anos consecutivos e em dois períodos de amostragem (Julho 2010/2011 e Janeiro 2011/2012). As variáveis analisadas foram: acúmulo de serrapilheira, teores de nutrientes na serrapilheira, estoque de carbono nos compartimentos serrapilheira e solo, índice de qualidade de resíduo vegetal, matéria orgânica do solo, acidez do solo, bases trocáveis, capacidade de troca de cátions, saturação por bases e alumínio, resistência do solo à penetração, densidade do solo, porosidade e agregação do solo. Os resultados apontaram que o uso do solo com sistema agroflorestal, mesmo após 22 anos de uso, pouco se diferencia da área preservada. A conversão da floresta em agroecossistemas potencializa os atributos químicos do solo e reduz, sensivelmente, o carbono estocado no compartimento serrapilheira, conforme observado na Roça de toco. O uso do solo com Pasto, por sucessivos anos, incrementa a densidade do solo, resistência à penetração do solo, microporosidade e reduz a macroporosidade do solo. Neste estudo, clara distinção entre as formas de uso e manejo do solo foram observadas nos estoques de serrapilheira sobre a superfície do solo e resistência à penetração.

O presente trabalho é uma tentativa de validar uma metodologia para estimar a produção de sedimentos para todo território Brasileiro. Foram utilizadas ferramentas de sistemas de informação geográfi ca (GIS), estatística espacial, modelagem e gerenciamento de bancos de dados aplicados a conservação de solos, permitindo combinar a equação Universal de Perda do Solo (USLE) com diferentes modelos de taxa de transferência de sedimentos (SDR). A metodologia utilizou como base de teste dados da rede sedimentométrica brasileira composta de 201 bacias. As estimativas foram analisadas por regressão linear múltipla obtendo valores de R2 de até de 46% entre dados observados e modelados. Observou-se a pouca sensibilidade do modelo USLE em relação ao fator de erosividade (fator R) quando duas observações por métodos diferentes diferem espacialmente em seus valores máximos entre 18000 MJ.mm.ha-1.h-1.ano-1 e 28000 MJ.mm.ha-1.h-1.ano-1 . Por outro lado o modelo mostrou-se sensível ao fator de cobertura do solo (Fator C da USLE) afetando as taxas máximas estimadas de erosão entre 160 Mg.ha-1.ano-1 ate 460 Mg.ha-1.ano-1. Nesse sentido a metodologia sugerida pode ser utilizada para dar indicativos sobre mudanças de uso da terra em escalas regionais e subsidiar tomadas de decisões quanto ao planejamento e gestão territorial. / This work is an attempt to validate a methodology for estimating sediment production for the whole Brazilian territory. Tools were used geographic information systems (GIS), spatial statistics, modeling and database management applied to soil conservation, allowing combine the Universal Soil Loss Equation (USLE) with different models of sediment transfer rate (SDR). The methodology used as test data of Brazilian sedimentometric network composed of 201 basins. The estimates were analysed by multiple linear regression getting values of R2 to 46% between observed and modelled data. Noted the low sensitivity of USLE model in relation to the erosivity factor (R factor) when two observations by different methods differ in their maximum values and spatial distribution of 18000 MJ.mm.ha-1.h-1.year-1 and 28000 MJ.mm.ha-1.h-1.year-1. the other aspects the model proved to be sensitive to soil coverage factor (factor C of USLE) affecting the estimated maximum rates of erosion between 160 Mg.ha-1.year-1 up to 460 Mg.ha-1.year-1.

Page xvi is missing from both the electronic and print copy / One-third of the North Island of New Zealand has been identified as requiring increased soil conservation if pastoral farming is to be sustainable. For over 50 years the planting of widely spaced poplar trees (Populus spp.) has been one of the main methods used to control soil erosion on hill pastures. Research has shown that these plantings have successfully decreased soil erosion but their impact on the productivity of pastoral farming has received little research attention. The research that has been undertaken has found poplars can suppress understorey pasture production by up to 40%, suggesting that farmers require more research information on the impact of planting conservation trees on the productivity of their farm if the use of conservation trees is to be more widely adopted on erosion prone land. The objective of this thesis was to provide comprehensive data on the relationship between the range of poplar densities used for soil conservation on the light and soil under poplars, and consequently the effect on understorey pastures. Three field sites on commercial sheep and beef hill farms, in regions with contrasting summer soil moisture availability, Manawatu (one site) and Central Hawke's Bay (two sites), were monitored for two years. Tree stocking rates ranged from 0 to 375 trees/ha. Measurements were based on units of four trees with most measurements either directly below the tree crowns or in the gaps between the trees, but more intensive transect measurements were also made. Photosynthetically active radiation (PAR) and the ratio of red to far red light (R:FR) were measured under the trees and in open pasture controls. Stand density indices used included all the commonly used measures of tree canopies, including digital photography, and stem diameter at breast height (DBH). PAR transmission was inversely related to all of the stand density indices with canopy closure based on digital photographs being the most robust of the indices used. PAR under the trees, relative to open pasture, was greater in the gaps than below tree crowns. Under a completely closed canopy, PAR transmission was reduced to 15-20% and 50-55% of the open pasture in summer and winter, respectively. The RFR under the trees, relative to open pasture, decreased markedly at high stand densities (allowing less than 40% PAR transmission) in summer, but was similar in winter. The change in PAR under the trees was shown to be a major factor limiting pasture growth, particularly directly below the tree crowns. For both summer and winter, canopy closure measured with a standard digital camera was strongly related to stand level PAR transmission (r2=0.88-0.97; P<0.0001) and was also a practical method of measuring canopy closure in the field. The soil measurements confirmed earlier research that soil pH increases under mature poplar trees. There was a 0.2 - 0.7 unit increase in soil pH in the upper 75 mm of soil over both contrasting regions. The soil fertility under the trees in terms of requirements for pasture growth was similar to that of the open pasture with calcium and potassium up to 2.2 and 9.0 quick test units higher in the soil under the trees than in the open pasture, respectively. The direct cause of the increased concentration of some cations under the trees was the annual tree leaf litter. Overall, the soil fertility under the trees had the potential to produce similar pasture production to that of the open pasture with the added advantage of less acid conditions. Averaged over all sites the respective annual net herbage accumulation (ANHA) under poplar canopy closures of 25, 50 and 75 % was estimated from the equations developed to be 77, 60 and 48% of the open pasture. The greatest decrease was directly below the tree crowns where at canopy closures greater than 20% the ANHA was a relatively constant 50% of open pasture. In the vertically projected gap between trees the ANHA decreased by 6.6% relative to open pasture for each 10% increase in canopy closure. At approximately 80% canopy closure there was no difference between the ANHA directly below the trees and in the gap. Pasture net herbage accumulation (NHA) under the trees relative to open pasture was at its lowest in summer and autumn (36% of open pasture under a closed canopy), and at its greatest in early spring before tree canopy leafed out (72% of open pasture under a closed canopy). The botanical composition and feed value of the pasture under the trees was broadly similar to that of the open pasture. The greatest impact of the poplars on the pasture was decreased NHA due to shading. The decrease in NHA directly below mature unpruned poplars is substantial and would decrease farm profitability if the poplar stand density were high over a large area of the farm. The use of poplars for soil conservation is essential but these results show the importance of managing trees through pruning and thinning so that canopy closure is minimised. ANHA under the trees can be maintained at 75% of the open pasture if canopy closure is prevented from exceeding 30-40%.

Diss. Uppsala : Sveriges lantbruksuniv., 2003.

Made available in DSpace on 2014-06-11T19:26:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-27Bitstream added on 2014-06-13T18:30:33Z : No. of bitstreams: 1 gomes_ln_me_botfca.pdf: 1547323 bytes, checksum: af8a2048dd0668a015c188e6b10591fc (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A instalação de processos erosivos em solos agricultáveis, além do prejuízo ambiental e produtivo da área, pode comprometer o ambiente à jusante, pelo transporte de sedimentos, o que se em mananciais de água, provoca seu assoreamento parcial ou até total. A construção de curvas de nível utilizando arado convencional é uma prática conservacionista bastante utilizada. Em terrenos com sulcos de erosão, mesmo após uniformização por gradagem, o trator altera constantemente seu percurso na busca do nível definido pelas estacas, gerando desuniformidade na profundidade de corte, conseqüentemente no nível da curva construída, podendo comprometer sua vida útil. Considerando curvas de nível construídas nas condições acima, em área de quatro hectares, erodida e à montante de mananciais de água, foram efetuados levantamentos topográficos detalhados, sendo um imediatamente após a construção dos canais e outro após a estabilização dos mesmos. Os dados foram processados pelo software Datageosis, com o objetivo de verificar a validade da utilização da modelagem numérica da superfície na caracterização da movimentação de solo nos canais. Com base na metodologia adotada foi possível concluir que a modelagem numérica da superfície, apoiada em pontos não 2 regularmente espaçados, não permitiu avaliar o volume de solo movimentado quando considerados todos os dados de campo. A avaliação foi possível somente através da comparação de perfis homólogos, construídos isoladamente, com base nos dados de cada uma das três feições de canais estudadas (relevo natural à montante, fundo do canal e camalhão), quando se constatou que o principal responsável pela diminuição da capacidade de retenção de água pelos canais foi o desgaste e empolamento do camalhão. / The erosive process causes environmental damage and productive prejudice in farm areas, and in addition they endanger with sediment transport the environment under this area, which provokes partial or total deposition of sediments in the rivers. The construction of level curves using conventional plow is a very widespread conservative practice. In lands with erosion gullies, even after for harrowing, the tractor constantly alters its course searching for the stakes which defines the level, generating variation in the court depth, consequently in the level of the built curve, reducing its useful life. Considering level curves built in the conditions above, in area of four hectares, with erosion above the springs of water, detailed topographical works were made, one before the construction of the channels and another after the stabilization of the same ones. The data were processed by the software DataGEOSIS, with the objective of verifying the validity of the use of the numerical surface modeling to characterize the soil movement in the channels. We concluded that the numerical surface modeling, supported in points not regularly spaced didn't allow evaluating the soil volume in all field data. The evaluation was only possible through the comparison of the same profiles, built separately, based on the data of each one of the three studied features of channels, when it was verified that the 4 main responsible for the decrease of the capacity of retention of water in the channels was the soil compactation of the bedding.

Made available in DSpace on 2016-06-02T18:57:27Z (GMT). No. of bitstreams: 1 2332.pdf: 18980729 bytes, checksum: 5eb52fa99d99debab782fe4508aec9de (MD5) Previous issue date: 2008-12-12 / Financiadora de Estudos e Projetos / Soil quality evaluation is an important strategy, as it allows producers to focus agriculture techniques to constantly develop and maintain adequate, selfsustainable productions equilibrium. This study evaluated rural activities environmental impact by the system APOIA-NovoRural, as well as the influence of different sugarcane production systems on soil quality through physical, chemical and biochemical indicators. Six sugarcane aguardente production establishments were selected in Piracicaba, Socorro, Jaguariúna, Holambra e Ribeirão Preto, in the state of São Paulo, Brazil. In each property two treatments were studied, sugarcane cultivated soil under organic or conventional system and, soil under native forest, taken as basal reference. The APOIA-NovoRural indicated better environmental performance on the organic than conventional system, emphasizing the establishments landscape ecology and administration. Most indicators pointed out better soil conservation contribution by organic system. Among them, aggregate stability (Ea), organic matter (MO), dehydrogenase (Des), polysaccharides (Poli) and microbial biomass (Bm) can be used as system sustainable indicators. Isolated values don t work as reliable and accurate indicators for soil conditions, however, when evaluated together through Principal Components Analysis (PCA), they are able to show the alterations occurring in the environment due to the different handling of the soil. Thus, the selected attributes can provide subsidy to a correct land use. / A avaliação da qualidade do solo é uma importante estratégia, pois permite aos produtores direcionar técnicas agrícolas para melhorias constantes visando estabelecer e manter produtividades adequadas ao equilíbrio de um sistema auto-sustentável. Este trabalho avaliou o impacto ambiental das atividades rurais através do sistema APOIA-NovoRural, bem como a influência de diferentes sistemas de produção de cana-de-açúcar na qualidade do solo, através de atributos físicos, químicos e bioquímicos. Foram estudadas seis propriedades de cultivo de cana-de-açúcar para produção de cachaça, nos municípios de Piracicaba, Socorro, Jaguariúna, Holambra e Ribeirão Preto, no Estado de São Paulo. Em cada propriedade estudaram-se dois tratamentos, solo cultivado com cana-de-açúcar sob sistema orgânico ou convencional e, solo sob mata nativa, tomado como referência. O APOIA-NovoRural indicou melhor desempenho ambiental no sistema orgânico em relação ao convencional, destacando-se as características da ecologia da paisagem e gestão e administração das propriedades. A maioria dos atributos indicou que o manejo realizado nas áreas sob cultivo orgânico contribuiu para a manutenção da qualidade do solo. Entre eles os parâmetros estabilidade de agregados (Ea), matéria orgânica (MO), desidrogenase (Des), polissacarídeo (Poli) e biomassa microbiana (Bm) destacaram-se como sensíveis para indicar modificações no ecossistema. Os valores isolados não serviram como indicadores precisos e confiáveis das condições do solo. No entanto, quando avaliados em conjunto, via Análise de Componentes Principais (ACP), mostraram-se sensíveis para captar as alterações ocorridas no ambiente devido às diferentes formas de uso do solo. Assim, os atributos selecionados podem fornecer subsídios para o planejamento do uso correto da terra.

Thesis (MTech (Civil Engineering))--Cape Technikon, 1992. / In the Western Cape, gully ("donga") erosion is characteristic of the Swartland area where the effects of the problem have reached spectacular dimensions. In 1942 the Social and Economic Planning Council commissioned an investigation into the distribution and prevention of gully erosion. This investigation was led by Professor W J Talbot of the University of Cape Town, with the collaboration of researchers from the University of Stellenbosch. This led to the "Swartland and Sandveld" publication in August 1945. Little progress has since been made. The gullies identified by Prof Talbot's team remain to this day. In most cases they have grown even longer and deeper. The present investigation aims to study a typical network in one catchment area and to propose measures for the reclamation or stabilization of gullies. Such measures must not only be effective but also economically justifiable. In reclaiming or stabilizing a donga, a key factor is the establishment of a foundation structure. Such a structure is essential for supporting semi-permanent structures and promoting the growth of grass and bushes. At present, however, no satisfactory methods are known for the design and construction of supporting walls In narrow, deep dongas, other than those methods that require a rock foundation. Furthermore, conventional methods would require a buttress of length 17 m for a retaining wall of height 4,4 m. The amount of concrete needed, would clearly be excessive. It is therefore one of the aims of this study to develop a retaining wall with a relatively short buttress. If finances permit, the retaining structure, will be built and the stabilization process carefully monitored for possible applications in the future.

Made available in DSpace on 2016-12-23T14:37:38Z (GMT). No. of bitstreams: 1 Jose Marcilio da Silva.pdf: 1307724 bytes, checksum: d09f0919618708be274d4001c04c2597 (MD5) Previous issue date: 2006-11-01 / Nowadays soybean culture occupies great area in Brazilian savannah region. And this commodity has a great commercial importance for economy of Brazil as source of richness. Geostatistics, which allows detecting existence of variability and spatial distribution, constituting an important tool for analysis and detail description of soil attributes. This work was carries out with objective to evaluate spatial variability of chemical and physical attributes of soils cultivated with soybean, under no-tillage (PD) and conventional-tillage (PC) systems. Data analysis was realized by means of classic statistics and geostatistics. Data were collected in Rio Verde Goiás State, at Fazenda Monte Alegre, where two sample areas were referenced by means of Global Positioning System (GPS), and established a fishnet with 44 points, with dimension of 40 x 55 m. It was studied in these areas the following attributes: (a) in the depths of 0 to 10 cm, 10 to 20 cm and 20 to 40 cm - soil density (Ds), microporosity (MiP), macroporosity (MaP), total porosity of the soil (Pt); (b) in the depths of 0 to 20 cm and 20 to 40 cm - mechanical resistance attributes of the soil to the penetration (RP) and soil moisture (U); and (c) in the depths 0 to 5 cm and 5 to 15 cm the following chemical attributes: the activity of hydrogen ions (pH in CaCl2), organic matter (MO), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), aluminum (Al), potential acidity (H+Al), sum of bases (SB), cation exchange capacity (CTC) and exchangeable base saturation (V). It was accomplished descriptive statistical analysis of the attributes, followed of a geostatistical analysis based in the presuppositions of stationary of the intrinsic hypothesis, from semivariograma analyses. After adjustments of theoretical models, it was applied kriging method to estimate no-sampled values in the field, by building thematic maps that shows spatial distribution for attributes. Eighty two and seventy three percent of chemical attributes showed normal distribution for PC and PD, respectively. All evaluated physical attributes in the three first depths presented normal distribution, while for the others two it was not observed the same behavior. In the depth 0 to 5 cm, the chemical attributes MO and H+Al did not show significant difference between cultivation systems, the same happened with Mg and CTC in the depth 5 to 15 cm. For the same cultivation system compared in these two depths, P, Mg and Al in PC and Ca in PD did not show significant difference. Most of the studied chemical attributes in PC and PD reveal spatial dependence between moderate and strong, except K that presents low spatial dependence in PC in the depth from 0 to 5 cm. All physical attributes demonstrated significant difference, with exception for Ds and Pt in the depth from 20 to 40 cm. Most of the evaluated physical attributes in PC show spatial dependence between moderate and strong, except MaP in the depth from 0 to 10 cm, Ds and MiP from 10 to 20 cm, MiP and MaP from 20 to 40 cm, and RP in the two considered depths. In PD attributes MiP in the three depths, Pt from 10 to 20 cm, Ds and MaP and U in the depth from 20 to 40 cm do not present spatial dependence. The use of the assigned semivariograms allowed verifying the same pattern of spatial dependence for chemical attributes pH, MO, Al, H+Al and CTC, and physical Ds and Pt in PC and in PD for RP. The soil management practice in PC area was decisive to increase soybean productivity in relation PD area. The use of the Geographic Information System (GIS), associate with geostatistical methods, supports decisions at soil management practice, this increases practical potential uses of these methods / A cultura da soja ocupa grandes extensões de área plantada na região do cerrado brasileiro e, é considerada um commodities de grande importância comercial para a economia do Brasil como fonte geradora de riqueza. A análise geoestatística permite detectar a existência da variabilidade e distribuição espacial, constituindo importante ferramenta na análise e descrição detalhada dos atributos do solo. O presente trabalho teve como objetivo avaliar a variabilidade espacial de atributos químicos e físicos do solo no cultivo de soja sob plantio direto (PD) e preparo convencional do solo (PC), em área de cerrado, usando a técnica da estatística clássica e da geoestatística na análise dos dados. Os dados foram coletados em duas áreas na Fazenda Monte Alegre, no município de Rio Verde Goiás, em pontos de amostragem georeferenciadas com auxílio de um sistema de posicionamento global (GPS), definidos segundo uma malha regular com 44 pontos, com dimensão de 40 x 55 m. Foram estudados no PD e PC nas profundidades 0 a 10 cm, 10 a 20 cm e 20 a 40 cm os seguintes atributos físicos: densidade do solo (Ds), microporosidade (MiP), macroporosidade (MaP), porosidade total do solo (Pt), e nas profundidades 0 a 20 cm e 20 a 40 cm os atributos resistência mecânica do solo à penetração (RP) e umidade do solo (U); e os seguintes atributos químicos nas profundidades 0 a 5 cm e 5 a 15 cm: potencial hidrogeniônico (pH em CaCl2), matéria orgânica (MO), fósforo (P), potássio (K), cálcio (Ca), magnésio (Mg), alumínio (Al), acidez potencial (H+Al), soma de bases (SB), capacidade de troca de cátions (CTC) e saturação por bases trocáveis (V). Foi realizada análise descritiva dos atributos, seguida da análise geoestatística com base nas pressuposições de estacionaridade da hipótese intrínseca pela análise a partir de semivariogramas. Após ajustes dos modelos teóricos, realizou-se a interpolação por krigagem para estimar valores não amostrados no campo, construindo os mapas temáticos de contornos para os atributos que apresentaram distribuição espacial. Oitenta e dois e setenta e três porcento dos atributos químicos apresentam distribuição normal para PD e PC, respectivamente. Os atributos físicos avaliados nas três primeiras profundidades apresentam cem porcento de distribuição normal, enquanto que nas outras duas não apresentam o mesmo comportamento. Na profundidade 0 a 5 cm, os atributos químicos MO e H+Al não apresentam diferença significativa entre os manejos, o mesmo ocorrendo com o Mg e a CTC na profundidade de 5 a 15 cm. Para o mesmo manejo comparado nas duas profundidades, o P, o Mg e o Al no PC e o Ca no PD não apresentam diferença significativa. A maioria dos atributos químicos avaliados no PC e PD apresenta dependência espacial entre moderada e forte, exceto o K que apresenta baixa dependência espacial no PC na profundidade de 0 a 5 cm. Todos os atributos físicos apresentam diferença significativa, com exceção para Ds e Pt na profundidade de 20 a 40 cm. A maioria dos atributos físicos avaliados no PC do solo apresenta dependência espacial entre moderada e forte, exceto a MaP na profundidade de 0 a 10 cm, Ds e MiP de 10 a 20 cm, MiP e MaP de 20 a 40 cm, e RP nas duas profundidades avaliadas. No PD, os atributos MiP nas três profundidades, a Pt de 10 a 20 cm, Ds e MaP e U na profundidade de 20 a 40 cm apresentam ausência de dependência espacial. O uso do semivariograma escalonado permite verificar o mesmo padrão de dependência espacial para os atributos químicos pH, MO, Al, H+Al e CTC, e físicos Ds e Pt no PC e no PD para RP. O manejo na área sob PC é decisivo no aumento da produtividade da soja em relação à área sob PD. O uso do sistema de informação geográfica associado a métodos geoestatísticos contribui com a tomada de decisão na implementação do manejo do solo, aumentando o potencial de utilização prática desses métodos