Jaqueline Dalla Rosa

Carbono orgânico e atributos químicos do solo em áreas florestais

The objective of this work was to evaluate organic carbon contents and soil chemical attributes in forest areas in Campo Belo do Sul, Santa Catarina, Brazil, with the following land use: native grassland (NG); 12-year-old loblolly pine (Pinus taeda) reforestation (P12); 20-year-old loblolly pine reforestation (P20); 18-year-old araucaria (Araucaria angustifolia) reforestation (A18); and native forest with araucaria (NF). The soil samples were systematically collected with eight replicates, in the layers of 0.0-0.05; 0.05-0.1; 0.1-0.2 and 0.2-0.4 m. The pinus and araucaria reforestations showed organic C stocks similar to those in native forest and grassland areas, reaching 12.5 to 14.2 kg m-2 in the layer of 0.0-0.4 m depth. Soil acidity and available P contents were highest, in the mean of the analyzed soil layers, under the P20 treatment. Soil nutrient status ranged from low to medium for available P and exchangeable K, Ca and Mg.

Processo de formação de crostas superficiais em razão de sistemas de preparo do solo e chuva simulada

A chuva provoca a modificacao da estrutura superficial do solo levando ao desenvolvimento de crostas. Este estudo avaliou a dinâmica da formacao de crostas superficiais por meio da analise e descricao micromorfologica de lâminas delgadas. O experimento foi conduzido em 2009 e 2010. Em parcelas de 15 x 30 m, foram implantados os diferentes sistemas de preparos do solo: preparo convencional (PC), preparo reduzido (PR) e sem preparo (SP). Dentro das parcelas instalaram-se as microparcelas de 1 x 1m e aplicaram-se diferentes lâminas de chuva simulada (0, 27, 54 e 80 mm) com intensidade de 80 mm h-1. Nas microparcelas, coletou-se uma amostra indeformada em que consistia em um bloco de solo de 0,07 x 0,05 x 0,12 m. Os blocos foram impregnados com resina e apos endurecimento e secagem total foram confeccionadas lâminas delgadas (4,5 x 8 cm), descritas, utilizando microscopio optico. Foi confeccionada uma lâmina delgada para cada chuva (0, 27, 54 e 80 mm) e para cada preparo do solo. Todos os sistemas de preparo avaliados demonstraram presenca de crostas; entretanto, o processo de formacao das crostas ocorreu com dinâmica diferenciada em cada sistema de preparo. O preparo convencional apresentou formacao de crostas a partir de 27 mm de chuva aplicada. O aumento da lâmina de chuva aplicada causou maior degradacao da estrutura superficial e maior espessura da camada encrostada. O preparo reduzido e o sistema sem preparo apresentaram condicoes de superficie irregulares com as chuvas aplicadas, ou seja, nao demonstraram modificacoes constantes da superficie do solo e na formacao das crostas, com o aumento da chuva, como constatado no preparo convencional. A analise das lâminas delgadas e a descricao micromorfologica permitiram satisfatoria observacao e conclusao dos processos e da dinâmica envolvida na formacao de crostas.

Deep subsoiling of a subsurface-compacted typical hapludult under citrus orchard

Soil management practices which increase the root depth penetration of citrus are important to the longevity and yield maintenance of this plant, especially in regions where long periods of drought are common, even in soil conventionally subsoiled to a depth of 30-40 cm, when the orchard was first established. The objective of this study was to evaluate the efficiency of subsoiling on the physical and hydric properties of a Typical Hapludult and fruit yield in a 14-year-old citrus orchard located in Piracicaba, SP. The treatments consisted of: no-subsoiling (with no tilling of the soil after the orchard was planted); subsoiling on one side of the plant lines (SUB. 1); and subsoiling on both sides of the plant lines (SUB. 2). The subsoiling treatments were carried out 1.5 m from the plant lines and to a depth of 0.8 m. Soil samples were taken 120 days after this operation, at four depths, in order to determine physical and hydric properties. Fruit yield was evaluated 150 days after subsoiling. Subsoiling between the plant lines of an old established citrus orchard alters the physical and hydric properties of the soil, which is reflected in increased soil macroporosity and unsaturated hydraulic conductivity, and reduced soil bulk density, critical degree-of-compactness and penetration resistance. The improvements in the physical and hydric properties of the soil were related to an increase in fruit number and orchard yield.

Hydro-physical characterization of soils under tropical semi-deciduous forest

The study of the hydro-physical behavior in soils using toposequences is of great importance for better understanding the soil, water and vegetation relationships. This study aims to assess the hydro-physical and morphological characterization of soil from a toposequence in Galia, state of Sao Paulo, Brazil). The plot covers an area of 10.24 ha (320 × 320 m), located in a semi-deciduous seasonal forest. Based on ultra-detailed soil and topographic maps of the area, a representative transect from the soil in the plot was chosen. Five profiles were opened for the morphological description of the soil horizons, and hydro-physical and micromorphological analyses were performed to characterize the soil. Arenic Haplustult, Arenic Haplustalf and Aquertic Haplustalf were the soil types observed in the plot. The superficial horizons had lower density and greater hydraulic conductivity, porosity and water retention in lower tensions than the deeper horizons. In the sub-superficial horizons, greater water retention at higher tensions and lower hydraulic conductivity were observed, due to structure type and greater clay content. The differences observed in the water retention curves between the sandy E and the clay B horizons were mainly due to the size distribution, shape and type of soil pores.

Atributos químicos do solo e produtividade de videiras alterados pelo manejo de coberturas verdes na Serra Gaúcha

Soil management can have effects on nutrient availability and fruit yield. The objective of this study was to evaluate the effect of phytomass management forms of different cover crop species on soil chemical properties related to organic matter, nutrient availability, and on grapevine yields. The experiment was carried out in Embrapa Uva e Vinho, in Bento Goncalves, RS, in Southern Brazil, on a Haplic Cambissol, in a vineyard established in 1989, using White and Rose Niagara grape in a horizontal overhead trelling system. The treatments established in 2002 were three cover crops: spontaneous native species, black oat (Avena strigosa), and a mixture of white clover (Trifolium repens) + red clover (Trifolium pratense) + annual ryegrass (Lolium multiflorum); and two management systems: desiccation by herbicide spraying and mechanical mowing, performed each autumn prior to cover crop resowing. The experiment had a completely randomized block design, with three replications. Soil acidity and nutrient contents were little influenced by the plant cover. In comparison with the mowed management, herbicide application increased exchangeable Ca and Mg, extracted P, and organic C levels in the soil. The grape yield in the seasons 2004 and 2006 was low in view to the cultivar potential, probably affect by climatic limitations, but was higher when black oat was used as plant cover instead of the mixture of plant covers.

Assessment of pedotransfer functions for estimating soil water retention curves for the amazon region

Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of 16 point or parametric PTFs reported in the literature on different soils from the south and southeast of the State of Para, Brazil. The PTFs tested were proposed by Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002), and Barros (2010). We used a database that includes soil texture (sand, silt, and clay), bulk density, soil organic carbon, soil pH, cation exchange capacity, and the SWRC. Most of the PTFs tested did not show good performance in estimating the SWRC. The parametric PTFs, however, performed better than the point PTFs in assessing the SWRC in the tested region. Among the parametric PTFs, those proposed by Tomasella et al. (2000) achieved the best accuracy in estimating the empirical parameters of the van Genuchten (1980) model, especially when tested in the top soil layer.O conhecimento da curva de retencao de agua (CRA) e essencial para compreender e modelar os processos hidraulicos no solo. No entanto, a determinacao direta do CRA consome tempo, e o custo e alto. Alem disso, e necessario grande numero de amostras, em razao da elevada variabilidade espacial e temporal das propriedades hidraulicas do solo. Uma alternativa e o uso de modelos, que sao chamados de funcoes de pedotransferencia (FPT), que estimam a CRA por meio de propriedades do solo de facil determinacao. O objetivo deste estudo foi testar a acuracia de 16 FPT, pontuais ou parametricas, existentes na literatura, em diferentes solos do sul e sudeste do Estado do Para, Brasil. As FPT testadas foram propostas por Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002) e Barros (2010). Utilizou-se um banco de dados contendo textura (areia, silte e argila), densidade do solo, carbono orgânico, pH do solo, capacidade de troca cationica e CRA. A maioria das FPT testadas nao demonstrou boa acuracia para estimar as CRA. As FPT parametricas apresentaram melhor desempenho do que as FPT pontuais em estimar a CRA dos solos na regiao. Entre as FPT parametricas, as propostas por Tomasella et al. (2000) obtiveram melhor acuracia em estimar os parâmetros empiricos do modelo de van Genuchten (1980), principalmente, quando testadas na primeira camada do solo.

SOIL FUNCTIONING IN A TOPOSEQUENCE UNDER RAINFOREST IN SÃO PAULO, BRAZIL

O estudo da dinâmica da agua no solo utilizando topossequencias e de grande importância para melhor compreender as relacoes solo-agua-vegetacao. Objetivou-se, com este trabalho, caracterizar fisico, hidrica e morfologicamente os solos da mata do Parque Estadual de Carlos Botelho. A parcela abrange uma area de 10,24 ha (320 x 320 m), localizada sob Floresta Ombrofila Densa (Mata Atlântica de Encosta). Com base nos mapas de solos ultradetalhados e mapas planialtimetricos dessa area, escolheu-se uma transecao representativa dos solos da parcela; nessa, foram abertas cinco trincheiras, onde foi feita a descricao morfologica dos diferentes horizontes dos solos. No estudo da dinâmica da agua no solo, foram feitas analises granulometricas, de densidade do solo e particulas, de curvas de retencao e de medidas de condutividade hidraulica saturada no campo, utilizando-se o permeâmetro de Guelph. Coletaram-se amostras indeformadas para realizar analises de imagens. Os Cambissolos apresentaram-se como os solos predominantes na parcela, mas tambem foram encontradas manchas de Neossolos e Gleissolos. No estudo da caracterizacao fisico-hidrica dos solos da topossequencia escolhida, observou-se mudanca na condutividade hidraulica entre as camadas superficiais e subsuperficiais, de alta/intermediaria para intermediaria/baixa permeabilidade. Essa variacao do comportamento da agua no solo tambem pode ser observada nas curvas de retencao de agua, que evidenciou maior retencao de agua nos horizontes subsuperficiais. Fatores como porosidade total, dimensao, forma e conexao entre os poros foram analisados por meio da analise de imagens. O comportamento fisico-hidrico dos solos foi influenciado pelas caracteristicas morfogenicas do solo.

Soil physical properties and grape yield influenced by cover crops and management systems

The use of cover crops in vineyards is a conservation practice with the purpose of reducing soil erosion and improving the soil physical quality. The objective of this study was to evaluate cover crop species and management systems on soil physical properties and grape yield. The experiment was carried out in Bento Goncalves, RS, Southern Brazil, on a Haplic Cambisol, in a vineyard established in 1989, using White and Rose Niagara grape (Vitis labrusca L.) in a horizontal, overhead trellis system. The treatments were established in 2002, consisting of three cover crops: spontaneous species (SS), black oat (Avena strigosa Schreb) (BO), and a mixture of white clover (Trifolium repens L.), red clover (Trifolium pratense L.) and annual rye-grass (Lolium multiflorum L.) (MC). Two management systems were applied: desiccation with herbicide (D) and mechanical mowing (M). Soil under a native forest (NF) area was collected as a reference. The experimental design consisted of completely randomized blocks, with three replications. The soil physical properties in the vine rows were not influenced by cover crops and were similar to the native forest, with good quality of the soil structure. In the inter-rows, however, there was a reduction in biopores, macroporosity, total porosity and an increase in soil density, related to the compaction of the surface soil layer. The M system increased soil aggregate stability compared to the D system. The treatments affected grapevine yield only in years with excess or irregular rainfall.

Avaliação de funções de pedotranferência para estimar curvas de retenção de água do solo na região amazônica

Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of 16 point or parametric PTFs reported in the literature on different soils from the south and southeast of the State of Para, Brazil. The PTFs tested were proposed by Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002), and Barros (2010). We used a database that includes soil texture (sand, silt, and clay), bulk density, soil organic carbon, soil pH, cation exchange capacity, and the SWRC. Most of the PTFs tested did not show good performance in estimating the SWRC. The parametric PTFs, however, performed better than the point PTFs in assessing the SWRC in the tested region. Among the parametric PTFs, those proposed by Tomasella et al. (2000) achieved the best accuracy in estimating the empirical parameters of the van Genuchten (1980) model, especially when tested in the top soil layer.O conhecimento da curva de retencao de agua (CRA) e essencial para compreender e modelar os processos hidraulicos no solo. No entanto, a determinacao direta do CRA consome tempo, e o custo e alto. Alem disso, e necessario grande numero de amostras, em razao da elevada variabilidade espacial e temporal das propriedades hidraulicas do solo. Uma alternativa e o uso de modelos, que sao chamados de funcoes de pedotransferencia (FPT), que estimam a CRA por meio de propriedades do solo de facil determinacao. O objetivo deste estudo foi testar a acuracia de 16 FPT, pontuais ou parametricas, existentes na literatura, em diferentes solos do sul e sudeste do Estado do Para, Brasil. As FPT testadas foram propostas por Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002) e Barros (2010). Utilizou-se um banco de dados contendo textura (areia, silte e argila), densidade do solo, carbono orgânico, pH do solo, capacidade de troca cationica e CRA. A maioria das FPT testadas nao demonstrou boa acuracia para estimar as CRA. As FPT parametricas apresentaram melhor desempenho do que as FPT pontuais em estimar a CRA dos solos na regiao. Entre as FPT parametricas, as propostas por Tomasella et al. (2000) obtiveram melhor acuracia em estimar os parâmetros empiricos do modelo de van Genuchten (1980), principalmente, quando testadas na primeira camada do solo.

Assessment of pedotransfer functions for estimating soil water retention curves for the amazon region Avaliação de funções de pedotranferência para estimar curvas de retenção de água do solo na região amazônica

Knowledge of the soil water retention curve (SWRC) is essential for understanding and modeling hydraulic processes in the soil. However, direct determination of the SWRC is time consuming and costly. In addition, it requires a large number of samples, due to the high spatial and temporal variability of soil hydraulic properties. An alternative is the use of models, called pedotransfer functions (PTFs), which estimate the SWRC from easy-to-measure properties. The aim of this paper was to test the accuracy of 16 point or parametric PTFs reported in the literature on different soils from the south and southeast of the State of Para, Brazil. The PTFs tested were proposed by Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002), and Barros (2010). We used a database that includes soil texture (sand, silt, and clay), bulk density, soil organic carbon, soil pH, cation exchange capacity, and the SWRC. Most of the PTFs tested did not show good performance in estimating the SWRC. The parametric PTFs, however, performed better than the point PTFs in assessing the SWRC in the tested region. Among the parametric PTFs, those proposed by Tomasella et al. (2000) achieved the best accuracy in estimating the empirical parameters of the van Genuchten (1980) model, especially when tested in the top soil layer.O conhecimento da curva de retencao de agua (CRA) e essencial para compreender e modelar os processos hidraulicos no solo. No entanto, a determinacao direta do CRA consome tempo, e o custo e alto. Alem disso, e necessario grande numero de amostras, em razao da elevada variabilidade espacial e temporal das propriedades hidraulicas do solo. Uma alternativa e o uso de modelos, que sao chamados de funcoes de pedotransferencia (FPT), que estimam a CRA por meio de propriedades do solo de facil determinacao. O objetivo deste estudo foi testar a acuracia de 16 FPT, pontuais ou parametricas, existentes na literatura, em diferentes solos do sul e sudeste do Estado do Para, Brasil. As FPT testadas foram propostas por Pidgeon (1972), Lal (1979), Aina & Periaswamy (1985), Arruda et al. (1987), Dijkerman (1988), Vereecken et al. (1989), Batjes (1996), van den Berg et al. (1997), Tomasella et al. (2000), Hodnett & Tomasella (2002), Oliveira et al. (2002) e Barros (2010). Utilizou-se um banco de dados contendo textura (areia, silte e argila), densidade do solo, carbono orgânico, pH do solo, capacidade de troca cationica e CRA. A maioria das FPT testadas nao demonstrou boa acuracia para estimar as CRA. As FPT parametricas apresentaram melhor desempenho do que as FPT pontuais em estimar a CRA dos solos na regiao. Entre as FPT parametricas, as propostas por Tomasella et al. (2000) obtiveram melhor acuracia em estimar os parâmetros empiricos do modelo de van Genuchten (1980), principalmente, quando testadas na primeira camada do solo.