38 research outputs found

    Soil loss ratio for three green manures

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    Um experimento sobre perdas de água e solo por erosão foi desenvolvido, durante seis anos agrícolas (1973/74 a 1978/79), no Centro Experimental de Campinas do Instituto Agronômico do estado de São Paulo, Brasil, em um Typic Haplortox, com vistas em avaliar a Razão de Perdas de Solo (RPS) para três leguminosas utilizadas como adubos verdes. As leguminosas estudadas foram a Crotalaria juncea L. (crotalária); Stizolobium aterrinum Piper et Tracy (mucunapreta) e Dolichos lablab L. (labelabe). Para determinar a razão de perdas de solo, foram estabelecidos quatro períodos das culturas isolados de 0-30, 30-60, 60-90 e 60-120 dias após a semeadura e períodos cumulativos de 0-30, 0-60, 0-90 e 0-120 dias após a semeadura. Os resultados obtidos mostraram maior proteção oferecida pela mucuna-preta à erosão, com valores de RPS de 0,28; 0,37; 0,17; e 0,09 para os períodos isolados de 0-30, 30-60; 60-90 e 60-120 dias após a semeadura. O labelabe apresentou, para a mesma situação, os valores de 0,50; 0,45; 0,27 e 0,19; enquanto, para a crotalária, os valores foram de 0,30; 0,42; 0,26 e 0,24. Os resultados mostraram proteção mais efetiva do solo à erosão a partir dos 60 dias após a semeadura, por parte das espécies avaliadas. A mucuna-preta apresentou maior efetividade na proteção do solo, seguida da crotalária, especialmente no primeiro período, e do labelabe, no estádio mais próximo ao florescimento.A field experiment of soil and water losses by erosion was carried out during six consecutive agricultural years (1973/74 to 1978/79) at the Experimental Center of Campinas, Instituto Agronomico of São Paulo, Brazil, in a Typic Haplorthox, to evaluate soil loss ratio (SLR) for three green manures: Crotalaria juncea L., Stizolobium aterrinum Piper et Tracy and Dolichos lablab L. Four cropstage periods were defined as isolated periods (0-30, 30-60, 60-90, and 60-120 days after planting), and as accumulated cropstage period (0-30, 0-60, 0- 90 or 0-120 days after planting). The results showed that Stizolobium aterrinum gave the best cover protection against soil loss, with values of soil loss ratio (SLR) of 0.28, 0.37, 0.17 and 0.19 for cropstage periods of 0-30, 30-60, 60-90 and 60-120 days after planting, respectively. Dolichos lablab showed SLR values of 0.50, 0.45, 0.27 and 0.19 and Crotalaria juncea of 0.30, 0.42, 0.26 and 0.24 for the same cropstage periods, respectively. The results also showed that the cover protection from the three green manures was more effective after 60 days of planting. Stizolobium was the most efficient cover, followed by Crotalaria, mainly in the first cropstage period and Dolichos, during flowering

    Relation among intensity, duration and frequency of rainfall in Mococa, State of São Paulo, Brazil

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    O objetivo deste trabalho foi realizar uma análise estatística das chuvas ocorridas em Mococa, Estado de São Paulo, de 1970 a 1990, incluindo a relação entre intensidade, duração e freqüência. Os dados analisados foram registrados com pluviógrafo instalado na estação experimental do Instituto Agronômico, em Mococa. Foram estudados os seguintes intervalos de duração: 5, 10, 15, 25, 30, 45, 60, 90 e 120 minutos. Para o estudo da freqüência de distribuição das chuvas intensas nos tempos de recorrência de 5, 10, 25, 50 e 100 anos, utilizou-se o método de Chow-Gumbel. Aplicou-se também o método dos mínimos quadrados para obter equação da mesma relação. Os resultados finais mostraram boa correlação entre os dois métodos, assim como os valores de intensidade máxima de chuva obtidos em cada duração, resultando nos coeficientes de regressão linear 0,9990 e 0,9920, respectivamente. Os resultados mostraram que a equação pode ser utilizada nos casos em que as intensidades máximas de chuva são necessárias.The objective of this work was to perform a statistical analysis of rainfall data gathered in Mococa, State of São Paulo, from 1970 to 1990, including the relationship between intensity, duration and frequency. The studied data were registered with a rain gauge located at the Experimental Station of the Instituto Agronômico, in Mococa, São Paulo State, Brazil. The relationship were studied for the following duration intervals: 5, 10, 15, 25, 30, 45, 60, 90, and 120 minutes. The Chow-Gumbel method was applied for the study of frequency distribution of intense precipitation for recurrency times of 5, 10, 25, 50, and 100 years. Also, the method of minimum squares was applied to obtain an equation for the same relationship. Final results showed good correlation between both methods, as well as with the maximum rainfall values obtained for each duration, resulting in linear regression coefficients of 0.9990 and 0.9920, respectively. Results indicated that the equation can be utilized for cases where values of maximum rainfall intensities are needed

    A decision support system for recommending land use and soil management

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    The objective of this work was to develop a decision support system to recommend land use and practices for soil conservation and management, which integrates an Expert System, Geographic Information System (GIS), a database and an interface to monitor input and output data and the messages passed between the subsystems. Using soil and slope maps, the developed system determines land capability from information stored in the database and also supplied by SIG; it recommends adequate uses for land capability class as well as practices for soil conservation and management and identifies conflict areas comparing the maps of land use with the land capability. All results can be visualized by the user through windows of the program, recorded or printed in form of report. In order to test the system, the municipality of Santo Antônio do Jardim, in the State of São Paulo, Brazil, was selected. The system is a powerful and efficient tool, permitting the evaluation of a region and thereby offering support for adequate decision making.Objetivou-se, com este trabalho, o desenvolvimento de um sistema de apoio à decisão para a recomendação de uso e manejo da terra, integrando Sistema Especialista, Sistema de Informações Geográficas, uma base de dados e uma interface para interpretar a entrada de dados do usuário e as mensagens passadas entre os subsistemas. O sistema desenvolvido determina a capacidade de uso da terra; recomenda usos adequados para cada classe de capacidade de uso como também práticas de conservação e manejo do solo e identifica áreas de conflito comparando os mapas de uso da terra com o mapa de capacidade de uso. Todos os resultados podem ser visualizados em janelas do programa, gravados ou impressos em forma de relatório. A área utilizada para testar o sistema é o Município de Santo Antônio do Jardim, SP. O sistema mostrou ser uma ferramenta poderosa e eficaz, permitindo avaliar-se uma região, oferecendo suporte para uma tomada de decisão mais fundamentada.86186

    Physical alterations induced by compaction of a coarse silty Dark Red Latosol

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    Visando avaliar o efeito de diferentes níveis de compactação nos atributos físicos: densidade do solo, porosidade total, conteúdos volumétricos de sólidos e de água e distribuição dos poros para retenção de água/ar, diferentes quantidades de massa de um Latossolo Vermelho-Escuro textura média foram introduzidas mediante uma prensa hidráulica em anéis de PVC de 0,88 dm3. Utilizando fórmulas desenvolvidas na mecânica dos solos e com os valores de densidades obtidos no feixe de raios-gama e densidade de partículas, observou-se que a aplicação de uma carga (pressão) sobre o solo reduziu linearmente tanto a porosidade total como o espaço de aeração, e aumentou na mesma magnitude os conteúdos volumétricos de sólidos e o de água.This research was conducted with the objective of studying physical alterations due to different levels of compaction in a coarse silty Dark Red Latosol (Oxisol). Compaction was obtained through a hydraulic press and bulk densities were checked in a gamma ray apparatus. Using soil mechanical equations, it was observed that the application of a strength over the soil reduced the total porosity and the aeration space, while increased in the same proportion the solid and water volumetric content

    CARACTERIZAÇÃO DE INDICADORES DA EROSÃO DO SOLO EM BACIAS HIDROGRÁFICAS COM O SUPORTE DE GEOTECNOLOGIAS E MODELO PREDICTIVO

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    This paper shows na application of the geotecnologies (Remote Sensing and GIS) in the section, of the high course of the basin of the River Cachoeirinha, above the town of Iracemápolis, S.P. The objective was to indicate the importance of the application of those techniques, with the support the USLE (Universal Soil Loss Equation) model, as a subside to the sustainable planning of the land use emphasizing the agricultural occupation. From the analysis of the data syntheses maps were produced refering to the indicators of hidric erosion of the soil: natural potential of erosion (NPE), risksand expectancy of erosion in relation to the agricultural occupation of the lands. More over, the series of photos, obtained though the field work, made it possible to evaluate the limitations of the USLE model in some situations. Key words: Land Use, Remote Sensing, GIS, Erosion, USLE modelO trabalho apresenta uma aplicação das geotecnologias (Sensoriamento Remoto e SIG) na seção do alto curso da bacia hidrográfica do Ribeirão Cachoeirinha, à montante da cidade de Iracemápolis, S.P. O objetivo foi indicar a importância da aplicação daquelas técnicas, com o suporte do modelo EUPS, como subsídio ao planejamento sustentável do uso das terras, com ênfase na ocupação agrícola. A partir da análise dos dados, foram geradas cartas de síntese referentes aos indicadores da erosão hídrica do solo: potencial natural de erosão (PNE), riscos e expectativa de erosão em relação à ocupação agrícola das terras. Além disso, a série de fotos, obtidas através do trabalho de campo, possibilitaram avaliar as limitações do modelo EUPS em determinadas situações. Palavras-chave: Uso da Terra, Sensoriamento Remoto, SIG, Erosão, Modelo EUP

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be 24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with δ<+34.5\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
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