ABSTRACT: Runoff in agricultural areas with intensive application of pig slurry can transport significant amounts of nutrients. This study evaluates the effects of different pig slurry (PS) application rates (0, 50, 100, and 200 m3 ha-1) on nutrient loss through runoff during soybean cultivation under no-tillage. It was conducted at two sites in southern Brazil, one on an Alfisol (27° 43' south and 50° 3' west) and one on an Inceptisol (27° 47' south and 50° 18' west). The PS was applied to the soil once at the beginning of the soybean cycle. Each plot was 11 m long in the direction of the slope and 3.5 m wide. To induce runoff, artificial rainfall was applied in four different tests (T1, T2, T3, T4), with an intensity of 65 mm h-1 for 90 minutes. The first test was performed one day after PS application, while the other tests were performed throughout the soybean cycle. During each test, runoff samples were collected at 10-min intervals after the beginning of runoff. The runoff amount and the NO3-, NH4+, P, and K+ concentrations in the runoff were measured. In T1, nutrient transport from the Alfisol and the Inceptisol increased with increasing PS doses. In some cases, this effect was still noticeable in T2 and T3, but not in the last test (T4). The transported amounts of NO3-, NH4+, P, and K+ decreased as the period between PS application and simulated rainfall increased. Regardless of the soil and the treatment, NO3- was transported in the greatest quantities, followed by K+, NH4+, and P.
Abstract: The objective of this work was to determine adjustment parameters for the revised universal soil loss equation (Rusle) of a soil subjected to pig slurry application. Treatments consisted of 0, 50, 100, and 200 m3 ha-1 pig slurry (PS), after the cultivation of black oat (Avena strigosa), besides the application of 50 m3 ha-1 PS for six times onto the soil surface in a temporal sequence, and a control treatment of soil without cultivation and without pig slurry application. The evaluations were performed for black oat shoot dry mass, root mass and crop residues semi-incorporated into the soil (RMR), soil losses by means of simulated rain, and the parameters for water erosion modeling. The pig slurry application onto soil surface caused a reduction in the values of the soil consolidation parameter (Cf), an increase in the mass of living and dead roots and cultural residues incorporated in the upper layer (0.0-0.1 m) of the soil (Bu), and a reduction in the subfactor prior land use (PLU) of the Rusle.
Resumo: O objetivo deste trabalho foi determinar parâmetros de ajuste para a equação universal de perda de solo revisada (Rusle) de um solo submetido à aplicação de dejeto líquido de suínos. Os tratamentos consistiram de 0, 50, 100 e 200 m3 ha-1 de dejeto líquido de suínos (DLS), após o cultivo de aveia-preta (Avena strigosa), além da aplicação de 50 m3 ha-1 de DLS por seis vezes à superfície do solo, em uma sequência temporal, e de um controle com solo sem cultivo e sem dejeto. As avaliações foram feitas quanto à massa de matéria seca da parte aérea da aveia-preta, à massa de raízes e aos resíduos da cultura semi-incorporados ao solo, às perdas de solo por meio de chuva simulada e aos parâmetros para modelagem de erosão hídrica. A aplicação de dejeto líquido de suínos à superfície do solo causou a diminuição dos valores de consolidação do solo (Cf), o aumento da massa de raízes vivas e mortas e dos resíduos culturais incorporados à camada superficial (0.0-0.1 m) do solo (Bu), e a redução dos valores de uso anterior da terra (PLU) na Rusle.
ABSTRACT: The conversion of native grassland into farmland causes changes in the soil. Tillage has profound effects on soil organic matter. The intensification of soil tillage decreases soil quality by reducing aggregate stability. Soil aggregate stability and soil organic matter are key indicators for soil quality and environmental sustainability in agro-ecosystems. The aim of the present study is to evaluate the total organic carbon content and the physical and chemical fractions of the organic matter in a soil under different uses and types of management over 27 years. Four soil tillage treatments with two annual crops were evaluated (no-tillage, NT; rotating tillage, RT; minimum tillage, MT; and conventional tillage, CT), as well as bare soil (BS) (standard plot of the Universal Soil Loss Equation - USLE) and natural grassland (NG) as a reference area. The experiment was carried out in an Inceptisol (Cambissolos) in southern Brazil. We determined total organic carbon (TOC) and particulate organic carbon (POC), and organic carbon associated with soil minerals (OCam). The chemical fractionation of carbon was into fulvic and humic acids, and humin. In addition, soil aggregates were divided into five size classes. The type of soil tillage affected the soil organic carbon content, namely TOC, POC, and OCam, as well as the composition of the physical and chemical fractions and their distribution in the arable soil layer. There was a positive relationship between stable aggregates and organic carbon in the soil: the higher the proportion of aggregates in class 1, the higher the organic carbon content. The results support the hypothesis that the carbon stock depends on intensification of a conservation tillage system with a continuous input of C through biomass, which maintains and supplies a continuous flow of C to the carbon transformation processes in the soil.
ABSTRACT Water erosion degrades the soil and contaminates the environment, and one influential factor on erosion is slope length. The aim of this study was to quantify losses of soil (SL) and water (WL) in a Humic Cambisol in a field experiment under natural rainfall conditions from July 4, 2014 to June 18, 2015 in individual events of 41 erosive rains in the Southern Plateau of Santa Catarina and to estimate soil losses through the USLE and RUSLE models. The treatments consisted of slope lengths of 11, 22, 33, and 44 m, with an average degree of slope of 8 %, on bare and uncropped soil that had been cultivated with corn prior to the study. At the end of the corn cycle, the stalk residue was removed from the surface, leaving the roots of the crop in the soil. Soil loss by water erosion is related linearly and positively to the increase in slope length in the span between 11 and 44 m. Soil losses were related to water losses and the Erosivity Index (EI30), while water losses were related to rain depth. Soil losses estimated by the USLE and RUSLE model showed lower values than the values observed experimentally in the field, especially the values estimated by the USLE. The values of factor L calculated for slope length of 11, 22, 33, and 44 m for the two versions (USLE and RUSLE) of the soil loss prediction model showed satisfactory results in relation to the values of soil losses observed.
In this study, specific methanogenic activity (SMA) tests were performed on textile sludge and food industry sludge. The textile sludge from an activated sludge was collected at the entrance of the secondary biologic clarifier and the food sludge was collected in a UASB reactor. Once collected, the sludges were characterized and tested for SMA. It was found that the microrganisms present in the food sludge had SMA of 0.17 gCOD-CH4 gSSV.d-1 and 337.05 mL of methane production, while the microrganisms of the textile sludge presented 0.10 gCOD-CH4 gSSV.d-1 of SMA and 3.04 mL of methane production. Therefore, the food sludge was more suitable to be used as a starting inoculum in UASB.
Nesse estudo procederam-se testes de atividade metanogênica específica (AME) para lodo de indústria têxtil e lodo de indústria alimentícia. O lodo têxtil (aeróbio), proveniente de um sistema de lodos ativados, foi coletado na entrada do decantador biológico secundário e o lodo alimentício (anaeróbio) foi coletado em um reator UASB. Uma vez coletados, os lodos foram caracterizados e submetidos a ensaios de AME. Constatou-se que os microrganismos presentes no lodo alimentício apresentaram AME de 0,17 gDQO-CH4 gSSV.d-1 e produção de metano de 337,05 mL, enquanto que os microrganismos do lodo têxtil apresentaram 0,10 gDQO-CH4 gSSV.d-1 de AME e 3,04 mL de produção de metano. Deste modo, o lodo têxtil apresentou menor atividade metanogênica e produção de metano, quando comparado ao lodo alimentício, indicando não ser viável seu uso como inóculo para a partida de um reator UASB.
The objective of this study was to evaluate the soil losses, as well as carbon and chemical samples in runoff through areas of pine (Pinus taeda), eucalyptus (Eucalyptus dunni) and a consortium of pasture with oat (Avena stringosa) and ryegrass (Lolium multiflorium) in the Fragosos river basin, in Concordia, SC. For this, rainfall simulations with mean intensities of 94 mm h-1 were conducted in September and November 2011, in plots of 1 m² established in the three areas. Runoff, loads carried of the sediment, and carbon and chemical concentrations were quantified in the experiment. The results showed that the concentrations of sediment and organic carbon were higher in the eucalyptus area. The largest concentrations of chemicals for all areas were nitrate, calcium, magnesium and potassium. Total carbon, organic carbon, sediment and nitrate were transported in higher loads in the eucalyptus area. With the exception of nitrate and chloride, the chemical loads carried were higher in the pasture area.
O objetivo deste estudo foi avaliar as perdas de solo, carbono e espécies químicas através do escoamento superficial em áreas de pinus (Pinus taeda), eucalipto (Eucalyptus dunni) e um consórcio de pastagem com aveia preta (Avena stringosa) e azevém (Lolium multiflorium), localizadas na bacia hidrográfica do Lajeado Fragosos, Concórdia, SC. Para tanto, simulações de chuva, com intensidade média de 94 mm h-1, foram realizadas, nos meses de setembro e novembro de 2011, em parcelas experimentais de 1 m² implantadas nas três áreas. Nos ensaios foram quantificadas as vazões escoadas superficialmente e determinadas às concentrações e cargas transportadas de sedimentos, carbono e espécies químicas. Os resultados mostraram que as concentrações de sedimento e carbono orgânico foram maiores na área de eucalipto. Nitrato, cálcio, magnésio e potássio foram as espécies químicas que apresentaram as maiores concentrações para todas as áreas. Carbono total, carbono orgânico, sedimento e nitrato foram os parâmetros com maior carga transportada, sendo esta na área de eucalipto. Contudo, para todas as espécies químicas, com exceção do nitrato e do cloreto, as cargas transportadas foram mais elevadas na pastagem.
This study presents concentrations and loads of nitrate and total inorganic phosphate in surface runoff infiltrating water and subsurface flow in the basin of Ribeirao Concordia, Lontras, SC - Brazil . Over a 109-day period, 102 samples were collected from three river sections, three lysimeters and three piezometric wells in the interior of the basin. Concentrations were compared with the standards given in the CONAMA Resolutions 357/2005 and 420/2009. Concentrations of nitrate and phosphate in lysimeter drainage water and flows were greater than those in river sections and piezometric wells. In the river sections and in surface flow from the lysimeter under pasture, nitrate concentrations were lower than the benchmarks set for such waters. Phosphate concentrations in the river sections and in both lysimeter surface runoff and in drainage water, and in the piezometers, all exceeded the standards defined in CONAMA Resolutions 357/2005 and 420/2009. Drainage waters in the lysimeters transported nitrate and phosphate loads greater than those in surface runoff, which in turn transported loads of the same order of magnitude as in river flow.
Neste trabalho foram determinadas as concentrações e as cargas de nitrato e de fosfato inorgânico total, na água de escoamento superficial, de drenagem e subterrânea, na bacia do Ribeirão Concórdia, Lontras, SC. Foram coletadas 102 amostras durante 109 dias, em três seções fluviométricas, três lisímetros e três poços piezométricos, distribuídos no interior da bacia. As concentrações foram comparadas com os padrões estabelecidos nas Resoluções CONAMA no. 357/2005 e no. 420/2009. As concentrações de nitrato e de fosfato no escoamento e drenagem dos lisímetros foram maiores que aquelas das seções fluviométricas e dos poços piezométricas. Nas seções fluviométricas e no escoamento superficial do lisímetro com pastagem as concentrações de nitrato foram inferiores aos padrões estabelecidos para essas águas. As concentrações de fosfato nas seções fluviométricas e nos lisímetros tanto do escoamento superficial quanto da drenagem e nos piezômetros, superaram os padrões das Resoluções CONAMA no. 357/2005 e no. 420/2009. As águas de drenagem nos lisímetros transportaram cargas de nitrato e de fosfato superiores àquelas do escoamento superficial; estas, por sua vez, transportaram cargas similares às dos rios.
Orchids are over-exploited in their natural environment due to their ornamental importance, which is leading some species to extinction. In vitro culture is an alternative for ex-situ conservation. Our objective was to determine an efficient medium for in vitro seed germination and initial seedling growth of Cattleya forbesii and Cattleya harrisoniana. Seeds of Cattleya forbesii were incubated in Murashige & Skoog (MS) medium (T1) and MS added with 2,5 g L-1 of activated charcoal (T2). For the last, plants with 1 ± 0,2 cm of height were submitted to the following treatments: T1, T2, MS reduced to the half strenght (T3) and MS reduced to the half strenght supplemented with 1,25 g L-1 of activated charcoal (T4). Thirty days after seed inoculation of C. forbesii, it was verified 45% and 90% of germination in T1 and T2, respectively. The addition of activated charcoal also promoted an increase in the height of the C. forbesii seedlings after 180 days of in vitro cultivation. After 240 days of culture of C. harrisoniana shoot height, total fresh mass, number of roots and leaves, length of the largest root and diameter of the shoots were significantly stimulated in T2 compared to the other treatments. We suggest the use of MS medium added with 2,5 g L-1 of activated charcoal because is significantly favorable for seed germination and initial growth for both species.
As orquídeas no ambiente natural sofrem exploração devido a sua importância ornamental, levando algumas espécies à extinção. O cultivo in vitro é uma forma alternativa para a conservação ex-situ. Procurou-se determinar um meio de cultura eficiente para a germinação in vitro de sementes e o crescimento inicial de plântulas de Cattleya forbesii, bem como para o crescimento de plântulas in vitro de Cattleya harrisoniana. No primeiro caso, sementes foram inoculadas em meio de cultura básico de Murashige & Skoog (MS) = T1 e MS básico acrescido de 2,5 g L-1 de carvão ativado (CA) = T2. No segundo, plântulas com 1 ± 0,2 cm de altura foram submetidas aos tratamentos T1, T2, MS com a metade da concentração original de macro-micronutrientes (T3) e MS com a metade da concentração original de macro-micronutrientes suplementado com 1,25 g L-1 de CA (T4). Verificou-se aos 30 dias em C. forbesii uma porcentagem de germinação de 45% em T1 e 90% em T2. A adição de CA ao meio de cultura trouxe aumento na altura de plântulas de C. forbesii de acordo com análises realizadas aos 180 dias de cultivo. Em relação ao crescimento de C. harrisoniana, aos 240 dias observou-se que todos os parâmetros médios avaliados (altura da parte aérea, massa de matéria fresca total, número de raízes e folhas, comprimento da maior raiz e diâmetro do pseudocaule) foram significativamente maiores em T2. Dessa forma, sugere-se o uso do meio MS acrescido de 2,5 g L-1 de CA (T2), uma vez que é significativamente favorável tanto para a germinação de sementes quanto para o crescimento de ambas as espécies.