Dejeto líquido de suínos: efeito no solo e nas perdas de K, Ca e Mg por erosão hídrica / Pig slurry: effect on soil and K, Ca and Mg losses by water erosion

O dejeto de suíno (DLS) é usado como fertilizante cujos nutrientes são perdidos por erosão e contaminam o ambiente se o dejeto é usado inadequadamente. Objetivou-se avaliar o efeito de DLS nosolo e na erosão, num Nitossolo Bruno. Os tratamentos, 0; 50; 100; e 200 m³ ha-1de DLS foram aplicados superficialmente após a semeadura uma vez em cada um dos cinco cultivos, e na palhada do último cultivo, totalizando 0, 250, 500 e 1000 m³ ha-1, na aveia (Avena strigosa), milho (Zea mays), nabo (Raphanus sativus L.) e soja (Glycine max), e nos resíduos de aveia. A chuva simulada (65 mm h-1e 75 minutos) foi aplicada três vezes no milho e quatro vezes no nabo, na soja, e nos resíduos, com um simulador debraços rotativos. Antes e depois da pesquisa, determinou-se o teor de K, Ca e Mg no solo. As chuvas aplicadas em cada momento compuseram um teste (T). O T1 ocorreu após a aplicação do DLS e os demais testes em intervalos que variaram entre 14 e 70 dias, em função do clima. Durante o escoamento, em intervalos de cincominutos coletaram-se amostras de enxurrada para determinar as perdas de água e o teor de K, Ca e Mg na água. O DLS não influenciou o teor dos nutrientes no solo. O teore as perdas totais dos nutrientes foram maiores com 1000 m3ha-1de DLS do que na ausência do dejeto. Com o aumento de escoamento, diminuiu o teor na enxurrada e aumentou a perda total, a qual aumentou também com o aumento de teor dos nutrientes na enxurrada. Recomenda-se aplicar menos do que 500 m3ha-1de DLS total no solo, mesmo em aplicações intervalares, devido à elevada perda de K, Ca e Mg pela erosão hídrica.(AU)

Pigg slurry (PS) is used as a fertilizer whose nutrients are lost through erosion and contaminate the environment if the manure is used inappropriately. The objective was to evaluate the effect of PS on soil and erosion, in a Alfisol soil. The treatments, 0; 50; 100; and 200 m³ ha-1of PS were applied superficially after sowing once in each of the five crops, and in the straw of the last crop, totaling 0, 250, 500 and 1000 m³ ha-1, in oat (Avena strigosa), corn (Zea mays), turnip (Raphanus sativusL.) and soybean (Glycine max), and in oat residues. The simulated rain (65 mm h-1and 75 minutes) was applied three times to corn and four times to turnip, soybeans, and residues, with a rotating arms simulator. Before and after the research, the content of K, Ca and Mg in thesoil was determined. The rainfall applied at each moment made up a test (T). T1 occurred after the application of the PS and the other tests at intervals that varied between 14 and 70 days, depending on the weather. During the runoff, at five-minute intervals, runoff samples were collected to determine water losses and the content of K, Ca and Mg in the water. The PS did not influence the nutrient content in the soil. The content and total losses of nutrients were higher with 1000 m3ha-1of PS than in theabsence of manure. With the increase in runoff, the content inthe runoff decreased and the total loss increased, which also increased with the increase in the nutrient content in the runoff. It is recommended to apply less than 500 m3ha-1of total PS inthe soil, even in interval applications, due to the high loss of K, Ca and Mg by water erosion.(AU)

Influence of rainfall regime in the Cerrado biome on the maintenance of traps built by Myrmeleon brasiliensis (Navás) (Neuroptera: Myrmeleontidae) larvae and the morphology of adults / Influência do regime de chuvas do bioma Cerrado na manutenção das armadilhas de larvas e na morfologia dos adultos de Myrmeleon brasiliensis (Navás) (Neuroptera: Myrmeleontidae)

Seasonality in the Cerrado biome of Brazil is characterized by a dry season and a rainy season, affecting the availability of water and generating nutritional limitations. Thus, plants and animals have developed adaptive mechanisms in order to survive in this environment. Insects known as antlions (Neuroptera: Myrmeleontidae) occur in areas of the Cerrado and build traps in dry soil to capture prey items. In the rainy season, these insects are unable to forage due to the waterlogged soil. The aim of this study was to investigate the influence of the rainfall regime in the Cerrado on aspects of trap-building behavior, larval development and morphological characteristics of adult antlions. Larvae of the antlion Myrmeleon brasiliensis (Návas, 1914) were observed and collected in an area of the Cerrado biome in the municipality of Aquidauana (MS), Brazil. Observations were performed in the rainy and dry seasons to determine the abundance of traps built by M. brasiliensis larvae. In the laboratory, experiments were performed involving the manipulation of the frequency of simulated rain on the traps. The results revealed that variations in rainfall due to seasonality in the Cerrado affect M. brasiliensis larvae, with greater foraging observed in the dry season. The laboratory experiments demonstrated that differences in the frequency of rains affect the mortality of the larvae, larval development time and the size of the adults. Thus, variations in rainfall patterns can lead to variations in the characteristics of the population structure of M. brasiliensis in areas of the Cerrado biome in Brazil.

No bioma Cerrado a sazonalidade (caracterizada por uma estação seca e outra chuvosa) afeta a disponibilidade de água e produz limitações nutricionais, de maneira que várias plantas e animais desenvolveram mecanismos adaptativos elaborados para sobreviver nesse ambiente. Insetos conhecidos como formiga-leão ocorrem em áreas de Cerrado e constroem suas armadilhas de captura de presas no solo seco. No período chuvoso as larvas ficam impedidas de forragear, dado o encharcamento do solo. Este trabalho tem como objetivo compreender a influência do regime de chuvas do Cerrado em aspectos do comportamento de construção da armadilha, no desenvolvimento das larvas e nas características morfológicas dos adultos. Larvas de formiga-leão Myrmeleon brasiliensis (Návas, 1914) foram observadas e coletadas em uma área de Cerrado no município de Aquidauana (MS), Brasil. Para verificar a abundância das armadilhas das larvas de M. brasiliensis foram realizadas observações no período chuvoso e seco. No laboratório foram realizados experimentos de manipulação da frequência de chuva nas armadilhas de M. brasiliensis. Como resultado foi observado que variações na sazonalidade do Cerrado afetam as larvas de M. brasiliensis, as quais são observadas forrageando em maior abundância na estação seca. Os experimentos de laboratório demonstraram que variações na frequência da chuva podem afetar, a mortalidade das larvas, o tempo de desenvolvimento das mesmas, o tamanho das armadilhas e o tamanho dos adultos. Sendo assim, variações no padrão de incidência de chuvas podem levar a variações nas características da estrutura da população de M. brasiliensis em áreas de Cerrado.

Weathering deterioration in pre-harvest of soybean seeds: physiological, physical, and morpho-anatomical changes

ABSTRACT: Successive cycles of water absorption and loss favor weathering deterioration, one of the main factors that affect the quality of soybean seeds. This study evaluated the physiological, physical, and morpho-anatomical changes in soybean seeds under weathering deterioration at the pre-harvest phase. Six soybean cultivars (BMX Apolo, DM 6563, NS 5959, NA 5909, BMX Potência, and TMG 1175) were produced in a greenhouse and underwent weathering deterioration through a rainfall simulation system, applying 0, 60, 120, and 180 mm of precipitation at pre-harvest phase. Each rainfall level was divided into two applications at an interval of 72 h: 60 mm (30 + 30), 120 mm (60 + 60), and 180 mm (90 + 90). After harvest, the seeds were evaluated for germination, vigor, physical and morpho-anatomical properties. Weathering deterioration induced by simulated rainfall at the pre-harvest phase contributes to the reduction in soybean seed germination and vigor and is conditioned by the soybean genotype. The increase in intensity of simulated rainfall led to a more significant weathering damage in seeds, as evidenced by the X-ray and tetrazolium test. Cultivars DM 6563 and BMX Potência were more susceptible, while NA 5909 was less susceptible to weathering deterioration (especially at the highest level; 120 mm and 180 mm). Anatomical changes caused by weathering deterioration lead to cell compaction and rupture, mainly in the cell layers of the hourglass and parenchyma, forming intracellular spaces. The presence of weathering damage caused a reduction in physiological soybean seed quality.

Supplemental irrigation using brackish water on maize in tropical semi-arid regions of Brazil: yield and economic analysis

ABSTRACT: Supplemental irrigation during dry spells could reduce maize yield losses in tropical semi-arid regions, notably in small farms. However, good quality water reserves are not sufficient to meet the demands of farming communities. Consequently, our objective was to evaluate the productivity and profitability of maize under different simulated rainfall scenarios, with and without supplemental irrigation (SI) with brackish water. The field experiments were carried out during the cropping seasons of 2018 and 2019 on Ultisol. The experiment followed a randomized block design in the split-plot scheme with four replicates. The plots were formed by simulating the water supply in the soil corresponding to four water scenarios (rainy, normal, drought and severe drought), and the sub-plots with or without SI with brackish water (Electrical conductivity of 4.5 dS m1). Mean yields of green maize ears were 13,083, 11,532, 10,358 and 9,609 kg ha1 for rainy, normal, drought and severe drought scenarios, as supplemented with brackish water. For the same treatments without SI the values were 11,394, 7,896, 3,913 and 1,374 kg ha1, respectively. Data on farmer's income showed that under normal, drought and severe drought supplementation with brackish water becomes economically advantageous from 0.9, 1.0 and 2.4 ha, respectively, while maize cultivation without SI is not advantageous under the last two scenarios. For severe drought conditions, however, SI using brackish water reduced commercial yield by 27 % with negative effects on the farmers profitability. In this case, it is necessary to use water with either lower salinity or select salt tolerant crops.

Weathering deterioration in pre-harvest of soybean seeds: physiological, physical, and morpho-anatomical changes

Successive cycles of water absorption and loss favor weathering deterioration, one of the main factors that affect the quality of soybean seeds. This study evaluated the physiological, physical, and morpho-anatomical changes in soybean seeds under weathering deterioration at the pre-harvest phase. Six soybean cultivars (BMX Apolo, DM 6563, NS 5959, NA 5909, BMX Potência, and TMG 1175) were produced in a greenhouse and underwent weathering deterioration through a rainfall simulation system, applying 0, 60, 120, and 180 mm of precipitation at pre-harvest phase. Each rainfall level was divided into two applications at an interval of 72 h: 60 mm (30 + 30), 120 mm (60 + 60), and 180 mm (90 + 90). After harvest, the seeds were evaluated for germination, vigor, physical and morpho-anatomical properties. Weathering deterioration induced by simulated rainfall at the pre-harvest phase contributes to the reduction in soybean seed germination and vigor and is conditioned by the soybean genotype. The increase in intensity of simulated rainfall led to a more significant weathering damage in seeds, as evidenced by the X-ray and tetrazolium test. Cultivars DM 6563 and BMX Potência were more susceptible, while NA 5909 was less susceptible to weathering deterioration (especially at the highest level; 120 mm and 180 mm). Anatomical changes caused by weathering deterioration lead to cell compaction and rupture, mainly in the cell layers of the hourglass and parenchyma, forming intracellular spaces. The presence of weathering damage caused a reduction in physiological soybean seed quality.

Weathering deterioration in pre-harvest of soybean seeds: physiological, physical, and morpho-anatomical changes

Successive cycles of water absorption and loss favor weathering deterioration, one of the main factors that affect the quality of soybean seeds. This study evaluated the physiological, physical, and morpho-anatomical changes in soybean seeds under weathering deterioration at the pre-harvest phase. Six soybean cultivars (BMX Apolo, DM 6563, NS 5959, NA 5909, BMX Potência, and TMG 1175) were produced in a greenhouse and underwent weathering deterioration through a rainfall simulation system, applying 0, 60, 120, and 180 mm of precipitation at pre-harvest phase. Each rainfall level was divided into two applications at an interval of 72 h: 60 mm (30 + 30), 120 mm (60 + 60), and 180 mm (90 + 90). After harvest, the seeds were evaluated for germination, vigor, physical and morpho-anatomical properties. Weathering deterioration induced by simulated rainfall at the pre-harvest phase contributes to the reduction in soybean seed germination and vigor and is conditioned by the soybean genotype. The increase in intensity of simulated rainfall led to a more significant weathering damage in seeds, as evidenced by the X-ray and tetrazolium test. Cultivars DM 6563 and BMX Potência were more susceptible, while NA 5909 was less susceptible to weathering deterioration (especially at the highest level; 120 mm and 180 mm). Anatomical changes caused by weathering deterioration lead to cell compaction and rupture, mainly in the cell layers of the hourglass and parenchyma, forming intracellular spaces. The presence of weathering damage caused a reduction in physiological soybean seed quality.(AU)

Supplemental irrigation using brackish water on maize in tropical semi-arid regions of Brazil: yield and economic analysis

Supplemental irrigation during dry spells could reduce maize yield losses in tropical semi-arid regions, notably in small farms. However, good quality water reserves are not sufficient to meet the demands of farming communities. Consequently, our objective was to evaluate the productivity and profitability of maize under different simulated rainfall scenarios, with and without supplemental irrigation (SI) with brackish water. The field experiments were carried out during the cropping seasons of 2018 and 2019 on Ultisol. The experiment followed a randomized block design in the split-plot scheme with four replicates. The plots were formed by simulating the water supply in the soil corresponding to four water scenarios (rainy, normal, drought and severe drought), and the sub-plots with or without SI with brackish water (Electrical conductivity of 4.5 dS m−1). Mean yields of green maize ears were 13,083, 11,532, 10,358 and 9,609 kg ha−1 for rainy, normal, drought and severe drought scenarios, as supplemented with brackish water. For the same treatments without SI the values were 11,394, 7,896, 3,913 and 1,374 kg ha−1, respectively. Data on farmer's income showed that under normal, drought and severe drought supplementation with brackish water becomes economically advantageous from 0.9, 1.0 and 2.4 ha, respectively, while maize cultivation without SI is not advantageous under the last two scenarios. For severe drought conditions, however, SI using brackish water reduced commercial yield by 27 % with negative effects on the farmers’ profitability. In this case, it is necessary to use water with either lower salinity or select salt tolerant crops.

Supplemental irrigation using brackish water on maize in tropical semi-arid regions of Brazil: yield and economic analysis

Supplemental irrigation during dry spells could reduce maize yield losses in tropical semi-arid regions, notably in small farms. However, good quality water reserves are not sufficient to meet the demands of farming communities. Consequently, our objective was to evaluate the productivity and profitability of maize under different simulated rainfall scenarios, with and without supplemental irrigation (SI) with brackish water. The field experiments were carried out during the cropping seasons of 2018 and 2019 on Ultisol. The experiment followed a randomized block design in the split-plot scheme with four replicates. The plots were formed by simulating the water supply in the soil corresponding to four water scenarios (rainy, normal, drought and severe drought), and the sub-plots with or without SI with brackish water (Electrical conductivity of 4.5 dS m−1). Mean yields of green maize ears were 13,083, 11,532, 10,358 and 9,609 kg ha−1 for rainy, normal, drought and severe drought scenarios, as supplemented with brackish water. For the same treatments without SI the values were 11,394, 7,896, 3,913 and 1,374 kg ha−1, respectively. Data on farmer's income showed that under normal, drought and severe drought supplementation with brackish water becomes economically advantageous from 0.9, 1.0 and 2.4 ha, respectively, while maize cultivation without SI is not advantageous under the last two scenarios. For severe drought conditions, however, SI using brackish water reduced commercial yield by 27 % with negative effects on the farmers profitability. In this case, it is necessary to use water with either lower salinity or select salt tolerant crops.(AU)

Losses of water, soil, and nutrients during high-intensity simulated rainfall in two soil management systems different sources of fertilization / Perdas de água, solo e nutrientes durante chuva simulada de alta intensidade, em dois sistemas de manejo do solo e diferentes fontes de adubação

The goal of this study was to quantify the water, soil, and soluble nutrient losses during high-intensity rainfall simulated in two soil preparation systems with four sources of fertilization. Forty-five days after the corn seeding, a 120 mm h-1 intensity rainfall was simulated during 90 min in field plots with conventional tillage (CT) or no-tillage (NT). Each system had four repetitions with the fertilizer treatments, including without fertilization, mineral, urban waste compost (UWC), and pig slurry. P, K, Ca, and K concentrations were measured in soluble form, in addition to electrical conductivity, pH, water, and soil losses. As expected, the greatest soil losses occurred with CT; however, the greatest water losses occurred with NT. Among the fertilizers, UWC was more efficient because it had the highest infiltration rates. The concentrations of P, K, Ca, and Mg did not exhibit any interaction between fertilization and soil tillage treatments. K was the nutrient that presented the greatest losses (kg ha-1) at the end of the simulated rainfall because of the highest concentrations (mg L-1) added to high runoff coefficients of 45% for CT and 77% for NT. Thus, the evaluated system with cover crops and minimum soil tillage was not sufficient to control nutrient transfer in the soluble form during intense rainfall events.(AU)

O objetivo do trabalho foi quantificar as perdas de água, solo e nutrientes na forma solúvel durante chuva simulada de alta intensidade, em dois sistemas de preparos do solo e quatro fontes de adubação. Quarenta e cinco dias após a semeadura do milho, uma chuva com intensidade de 120 mm h-1 foi simulada durante 90 minutos, em parcelas de campo sob preparo convencional (PC) e plantio direto (PD). Em cada preparo há quatro repetições dos tratamentos com adubação: sem fertilização, mineral, composto de lixo urbano (CO), e dejetos de suíno. Foram mensuradas as concentrações de P, K, Ca, Mg na forma solúvel, além da condutividade elétrica - Ce, pH, perda de água e solo. Conforme esperado as maiores perdas de solo ocorreram para o PC, entretanto, as maiores perdas de água no PD. Entre as adubações, o CO foi o mais eficiente, pois apresentou as maiores taxas de infiltração. As concentrações de P, K, Ca e Mg não apresentaram interação entre os tratamentos de adubação e os tratamentos de preparo do solo. O K foi o nutriente que apresentou as maiores perdas (kg ha-1) ao final da chuva simulada, devido as maiores concentrações (mg L-1) somado aos altos coeficientes de escoamento superficial sendo 45% para o preparo convencional e 77% para o plantio direto. Ao final, o sistema avaliado com plantas de cobertura e mínimo revolvimento do solo não foi suficiente para controlar a transferência de nutrientes na forma solúvel durantes eventos de chuvas intensas.(AU)

Selamento superficial e formação de crosta em solos representativos do Estado da Paraíba / Surface sealing and crust formation in Paraíba State representative soils

A formação de selo e crosta superficial no solo tem consequências diretas para o desenvolvimento das culturas e qualidade ambiental, alterando sua estrutura, diminuindo a disponibilidade de água para as plantas e potencializando os efeitos da erosão. Diante disto, o presente trabalho teve como objetivo avaliar as alterações causadas por sucessivos eventos de precipitação na superfície dos solos. Foram avaliadas quatro classes de solos: Latossolo Amarelo (LA); Argissolo Vermelho (PV); Neossolo Litólico (RL); Luvissolo Háplico (TX). O critério de seleção teve como base o grau de desenvolvimento pedogenético. O experimento foi conduzido sob chuva simulada, em parcelas experimentais com área útil de 0,3481 m², com solo descoberto e declividade de 0,10 mm-1. Os testes foram realizados com intensidade média da precipitação ajustada em 85 mm h-1 durante 75 minutos, aplicadas em três eventos consecutivos com intervalos de 7 dias, para determinar os efeitos da formação do selamento superficial durante a chuva e a formação de crosta após o período de secagem do solo. Foram avaliadas as variáveis hidráulicas do escoamento, a perda de solo (PSi), taxa de desagregação do solo em entressulcos (Di) e o fator de erodibilidade em entressulcos (Ki). A formação de selamento e de crostas superficiais foram observadas com aumento da velocidade de escoamento e da descarga liquida, e a diminuição da altura da lâmina de água, assim como alterações em PSi, Di e Ki, sendo no primeiro evento de chuva simulada a maior contribuição para formação do encrostamento superficial. O TC se mostrou o mais estável após os eventos sucessivos de chuva simulada, mesmo tendo a rugosidade superficial modificada, não apresentou alterações significativas nas perdas de solo, taxa de desagregação e erodibilidade do solo em entresulco.

The formation of seal and surface crust in the soil has direct consequences for the development of the crops and environmental quality, altering the soil structure, reducing the availability of water to the plants and favoring the erosion. The objective of this study was to evaluate the changes caused by successive rainfall events on the soil surface. Four soils were evaluated: Ferralsol; Acrisol; Leptsol; Luvisol. The selection criterion was based on pedogenetic development. The experiment was conducted under simulated rainfall, in experimental plots with a useful area of 0,3481 m², uncovered soil and slope of 0.10 mm-1. The tests were performed with mean precipitation intensity of 85 mm h-1 for 75 min, applied in three consecutive events at 7 day intervals, to determine the effects of surface sealing during rainfall and crust formation after the soil drying period. The hydraulic flow variables, the soil losses (PSi), soil disaggregation rate in interrill (Di) and the interrill erodibility factor (Ki) were evaluated. The formation of sealing and surface crusts were observed with increase of the flow velocity and liquid discharge, and the decrease of water sheet height, as well as in the changes in PSi, Di and Ki, being in the first event of simulated rainfall the greater contribution to formation of superficial crusting. LV showed the most stable after the successive events of simulated rainfall, even though the surface roughness was modified, did not present significant changes in the soil losses, disaggregation rate and soil interrill erodibility.

Selamento superficial e formação de crosta em solos representativos do Estado da Paraíba / Surface sealing and crust formation in Paraíba State representative soils

A formação de selo e crosta superficial no solo tem consequências diretas para o desenvolvimento das culturas e qualidade ambiental, alterando sua estrutura, diminuindo a disponibilidade de água para as plantas e potencializando os efeitos da erosão. Diante disto, o presente trabalho teve como objetivo avaliar as alterações causadas por sucessivos eventos de precipitação na superfície dos solos. Foram avaliadas quatro classes de solos: Latossolo Amarelo (LA); Argissolo Vermelho (PV); Neossolo Litólico (RL); Luvissolo Háplico (TX). O critério de seleção teve como base o grau de desenvolvimento pedogenético. O experimento foi conduzido sob chuva simulada, em parcelas experimentais com área útil de 0,3481 m², com solo descoberto e declividade de 0,10 mm-1. Os testes foram realizados com intensidade média da precipitação ajustada em 85 mm h-1 durante 75 minutos, aplicadas em três eventos consecutivos com intervalos de 7 dias, para determinar os efeitos da formação do selamento superficial durante a chuva e a formação de crosta após o período de secagem do solo. Foram avaliadas as variáveis hidráulicas do escoamento, a perda de solo (PSi), taxa de desagregação do solo em entressulcos (Di) e o fator de erodibilidade em entressulcos (Ki). A formação de selamento e de crostas superficiais foram observadas com aumento da velocidade de escoamento e da descarga liquida, e a diminuição da altura da lâmina de água, assim como alterações em PSi, Di e Ki, sendo no primeiro evento de chuva simulada a maior contribuição para formação do encrostamento superficial. O TC se mostrou o mais estável após os eventos sucessivos de chuva simulada, mesmo tendo a rugosidade superficial modificada, não apresentou alterações significativas nas perdas de solo, taxa de desagregação e erodibilidade do solo em entresulco.(AU)

The formation of seal and surface crust in the soil has direct consequences for the development of the crops and environmental quality, altering the soil structure, reducing the availability of water to the plants and favoring the erosion. The objective of this study was to evaluate the changes caused by successive rainfall events on the soil surface. Four soils were evaluated: Ferralsol; Acrisol; Leptsol; Luvisol. The selection criterion was based on pedogenetic development. The experiment was conducted under simulated rainfall, in experimental plots with a useful area of 0,3481 m², uncovered soil and slope of 0.10 mm-1. The tests were performed with mean precipitation intensity of 85 mm h-1 for 75 min, applied in three consecutive events at 7 day intervals, to determine the effects of surface sealing during rainfall and crust formation after the soil drying period. The hydraulic flow variables, the soil losses (PSi), soil disaggregation rate in interrill (Di) and the interrill erodibility factor (Ki) were evaluated. The formation of sealing and surface crusts were observed with increase of the flow velocity and liquid discharge, and the decrease of water sheet height, as well as in the changes in PSi, Di and Ki, being in the first event of simulated rainfall the greater contribution to formation of superficial crusting. LV showed the most stable after the successive events of simulated rainfall, even though the surface roughness was modified, did not present significant changes in the soil losses, disaggregation rate and soil interrill erodibility.(AU)

Impact of pervious pavement in urban areas on catchment basin recovery / Impacto da utilização de pavimentação permeável em áreas urbanas na recuperação de bacias hidrográficas

Urbanization and disorderly occupation of urban areas have created several environmental problems, such as floods. Among the main causes of these problems is soil sealing associated with urban sprawl. Impervious surfaces provide less precipitation to recharge catchment basins by diverting water that should be restored in that region to other basins. This study compares two existing paving systems: concrete pavers with permeable joints and porous concrete pavers. Our objective was to learn which system better promotes the recovery of catchment basins and, consequently, mitigate problems caused by increasing surface runoff in urban areas. In order to reach the results, precipitations were simulated using lysimeters and a rainfall simulation infiltrometer at rainfall rates of 45, 60, and 90 mm h-1. The analyzed paving systems represented characteristics of public sidewalks. This experiment indicates that porous concrete pavers (99.86%) and concrete pavers (99.59%) present mean infiltration similar to that of grass cover (100%) and thereby can promote water infiltration into soil and the recovery of catchment basins in urban areas.

A urbanização e a ocupação desordenada das cidades criaram diversos problemas ambientais, como as inundações. Entre as causas destas ocorrências está, principalmente, a impermeabilização dos solos nas cidades, que ocorre pela interferência e necessidade do homem em utilizar mais espaço. As superfícies impermeabilizadas acabam proporcionando uma menor recarga das bacias hidrográficas, transferindo para outras bacias a quantidade de água que deveria ser reposta naquela região, desta forma prejudicam a recuperação das bacias onde ocorrem as percolações. O presente estudo faz um comparativo entre duas tecnologias existentes no mercado comercialmente conhecidos como paver e o piso drenante, e aponta qual destas pode auxiliar na recuperação das bacias hidrográficas e, consequentemente, reduzir os problemas causados pelo aumento do escoamento superficial nas regiões urbanas. Para chegar ao resultado foram simuladas precipitações utilizando um infiltrômetro de aspersão em intensidades correspondentes a 45, 60 e 90 mm h-1, e lisímetros onde as coberturas correspondem às características de passeios públicos utilizando as tecnologias a serem analisadas como cobertura de solo. Este experimento apontou que as peças de concreto permeável (piso drenante) (99,86%) e as peças de concreto com juntas alargadas (paver) (99,59%) apresenta valores médios da taxa de percolação (Figura 3D) assemelhadaà cobertura de grama (100%) e desta forma podem ser utilizadas como tecnologias para infiltração deágua no solo auxiliando na recuperação das bacias hidrográficas das zonas urbanas.

Impact of pervious pavement in urban areas on catchment basin recovery / Impacto da utilização de pavimentação permeável em áreas urbanas na recuperação de bacias hidrográficas

Urbanization and disorderly occupation of urban areas have created several environmental problems, such as floods. Among the main causes of these problems is soil sealing associated with urban sprawl. Impervious surfaces provide less precipitation to recharge catchment basins by diverting water that should be restored in that region to other basins. This study compares two existing paving systems: concrete pavers with permeable joints and porous concrete pavers. Our objective was to learn which system better promotes the recovery of catchment basins and, consequently, mitigate problems caused by increasing surface runoff in urban areas. In order to reach the results, precipitations were simulated using lysimeters and a rainfall simulation infiltrometer at rainfall rates of 45, 60, and 90 mm h-1. The analyzed paving systems represented characteristics of public sidewalks. This experiment indicates that porous concrete pavers (99.86%) and concrete pavers (99.59%) present mean infiltration similar to that of grass cover (100%) and thereby can promote water infiltration into soil and the recovery of catchment basins in urban areas.(AU)

A urbanização e a ocupação desordenada das cidades criaram diversos problemas ambientais, como as inundações. Entre as causas destas ocorrências está, principalmente, a impermeabilização dos solos nas cidades, que ocorre pela interferência e necessidade do homem em utilizar mais espaço. As superfícies impermeabilizadas acabam proporcionando uma menor recarga das bacias hidrográficas, transferindo para outras bacias a quantidade de água que deveria ser reposta naquela região, desta forma prejudicam a recuperação das bacias onde ocorrem as percolações. O presente estudo faz um comparativo entre duas tecnologias existentes no mercado comercialmente conhecidos como paver e o piso drenante, e aponta qual destas pode auxiliar na recuperação das bacias hidrográficas e, consequentemente, reduzir os problemas causados pelo aumento do escoamento superficial nas regiões urbanas. Para chegar ao resultado foram simuladas precipitações utilizando um infiltrômetro de aspersão em intensidades correspondentes a 45, 60 e 90 mm h-1, e lisímetros onde as coberturas correspondem às características de passeios públicos utilizando as tecnologias a serem analisadas como cobertura de solo. Este experimento apontou que as peças de concreto permeável (piso drenante) (99,86%) e as peças de concreto com juntas alargadas (paver) (99,59%) apresenta valores médios da taxa de percolação (Figura 3D) assemelhadaà cobertura de grama (100%) e desta forma podem ser utilizadas como tecnologias para infiltração deágua no solo auxiliando na recuperação das bacias hidrográficas das zonas urbanas.(AU)

Assessment of climate change impacts on water resources of the Purus Basin in the southwestern Amazon / Avaliação de impactos de mudanças climáticas nos recursos hídricos da Bacia do Purus no sudoeste da Amazônia

O conhecimento sobre os recursos hídricos é crítico para a adaptação diante das mudanças de longo prazo e ocorrência mais frequente de eventos extremos. Nas grandes secas de 2005 e 2010, um grande epicentro foi localizado no sudoeste da Amazônia sobre a Bacia do Rio Purus. Nesse sentido, foi realizada uma simulação hidrológica nessa bacia, para avaliar os impactos das mudanças climáticas sobre seus recursos hídricos ao longo do século 21. O balanço hídrico foi simulado utilizando o modelo hidrológico distribuído (MHD-INPE). As projeções climáticas futuras foram simuladas pelo modelo regional ETA-INPE forçado por 4 membros do modelo global HadCM3 sobre o cenário de emissões de gases de efeito estufa A1B-AR4/IPCC. Como simulado pelo ETA-INPE/HadCM3, a resposta média dos 4 membros para o cenário A1B representa uma redução de chuvas em até 11,1%, aumento de temperatura em até 4,4 °C, e aumento da velocidade do vento em até 8,4% para a Bacia do Purus até o fim do século 21. Sob essas condições, as projeções de descarga representam uma diminuição global de 27% na Bacia do Purus, com diferentes padrões entre as estações seca e úmida, bem como mudanças nas tendências sazonais. As consequências das mudanças climáticas projetadas são severas e provavelmente terão um grande impacto sobre a manutenção dos ecossistemas naturais e subsistência humana. Em um processo de adaptação a mudanças climáticas, a preservação da cobertura florestal natural da Bacia do Purus pode ter grande importância na retenção de água.(AU)

Knowledge about water resources is critical for climate adaptation in face of long-term changes and more frequent extreme events occurrence. During the major droughts of 2005 and 2010, a large epicenter was located in the southwestern Amazon over the Purus River Basin. In this sense, we conducted a hydrological simulation in this basin to assess the climate change impacts on its water resources throughout the 21st century. The water balance was simulated using the Distributed Hydrological Model (MHD-INPE). The future climate projections were simulated by the regional ETA-INPE model driven by a 4-member HadCM3 global model regarding the A1B-AR4/IPCC scenario of greenhouse gases emissions. As simulated by the ETA-INPE/HadCM3, the 4-members mean response for the A1B scenario represents a rainfall reduction of up to 11.1%, a temperature increase of up to 4.4 °C, and a wind speed increase of up to 8.4% in the Purus Basin by the end of 21st century. Under these conditions, the discharge projections represent an overall 27% decrease in the Purus Basin with different patterns between dry and wet season, as well as changes in seasonality trends. The consequences of projected climate change are severe and will probably have a great impact upon natural ecosystem maintenance and human subsistence. In a climate change adaptation process, the preservation of the natural forest cover of the Purus Basin may have great importance in water retention.(AU)

Water erosion in surface soil conditions: runoff velocity, concentration and D50 index of sediments in runoff

Water erosion and contamination of water resources are influenced by concentration and diameter of sediments in runoff. This study aimed to quantify runoff velocity and concentration and the D50 index of sediments in runoff under different soil surface managements, in the following treatments: i) cropped systems: no-tilled soil covered by ryegrass (Lolium multiflorum Lam.) residue, with high soil cover and minimal roughness (HCR); no tilled soil covered by vetch (Vicia sativa L.) residue, with high soil cover and minimal roughness (HCV); chiseled soil after ryegrass crop removing the above-ground residues and keeping only the root system, with high roughness (HRR); chiseled soil after vetch crop removing the above-ground residues and keeping only the root system, with high roughness (HRV); ii) bare and chiseled soil, with high roughness (BHR). The research was conducted on a Humic Dystrupept under simulated rainfall. The design was completely randomized and each treatment was replicated twice. Eight rainfall events of controlled intensity (65 mm h1) were applied to each treatment for 90 minutes. The D50 index, runoff velocity and sediment concentration were influenced by crop and soil management. Runoff velocity was more intensely reduced by cover crop residues than by surface roughness. Regardless of surface condition, the D50 index and concentration of sediment in runoff were lower under ryegrass than vetch crop. Runoff velocity and the D50 index were exponentially and inversely correlated with soil cover by residues and with surface roughness, while the D50 index was positively and exponentially correlated with runoff velocity.

Water erosion in surface soil conditions: runoff velocity, concentration and D50 index of sediments in runoff

Water erosion and contamination of water resources are influenced by concentration and diameter of sediments in runoff. This study aimed to quantify runoff velocity and concentration and the D50 index of sediments in runoff under different soil surface managements, in the following treatments: i) cropped systems: no-tilled soil covered by ryegrass (Lolium multiflorum Lam.) residue, with high soil cover and minimal roughness (HCR); no tilled soil covered by vetch (Vicia sativa L.) residue, with high soil cover and minimal roughness (HCV); chiseled soil after ryegrass crop removing the above-ground residues and keeping only the root system, with high roughness (HRR); chiseled soil after vetch crop removing the above-ground residues and keeping only the root system, with high roughness (HRV); ii) bare and chiseled soil, with high roughness (BHR). The research was conducted on a Humic Dystrupept under simulated rainfall. The design was completely randomized and each treatment was replicated twice. Eight rainfall events of controlled intensity (65 mm h1) were applied to each treatment for 90 minutes. The D50 index, runoff velocity and sediment concentration were influenced by crop and soil management. Runoff velocity was more intensely reduced by cover crop residues than by surface roughness. Regardless of surface condition, the D50 index and concentration of sediment in runoff were lower under ryegrass than vetch crop. Runoff velocity and the D50 index were exponentially and inversely correlated with soil cover by residues and with surface roughness, while the D50 index was positively and exponentially correlated with runoff velocity.(AU)

Deposit of pesticides without and with adjuvants on citrus seedlings following different intervals of artificial rain

ABSTRACT: For a crop protection product to achieve its goal, the product must be applied and remain on the leaves until it is absorbed. This situation may be compromised due to rainfall after spraying, thus necessitating reapplication which increase the overall cost. Application technology research has focused on alternatives and solutions to mitigate this effect through the use of adjuvants. The objective of this research was to evaluate the deposit of spraying liquid on citrus seedlings using the products spirodiclofen, propargite, imidacloprid, lambda cyhalothrin, copper oxychloride, and copper hydroxide with water mixed with the adjuvants polydimethylsiloxane and phosphatidylcholine. Seedlings were subjected to simulated rains of 10mm at intervals of 1, 6, 12 and 24h after spraying, and the remaining deposits of spraying liquid per leaf area were analyzed by spectrophotometry by assessing a metallic marker previously added in the spraying liquids. Variables were subjected to analysis of variance and Tukey's test (P<0.05). The rains that occurred soon after spraying resulted in decreased spraying liquids deposits on citrus leaves. Adjuvant phosphatidylcholine promoted the greatest retention of spraying liquid on citrus leaves after rainfall.

RESUMO: A aplicação de um produto fitossanitário deve assegurar que ocorra sua chegada e permanência das gotas sobre folhas até que sejam absorvidos para manifestação do efeito biológico. Essa situação pode ser comprometida pela ocorrência de chuvas após a pulverização, necessitando de reaplicações que elevam os custos. A tecnologia de aplicação busca alternativas e soluções para amenizar esse efeito, como o uso de adjuvantes. Objetivou-se, neste trabalho, avaliar o depósito de caldas fitossanitárias pulverizadas sobre mudas de citros, com os produtos espirodiclofeno, propargite, imidacloprido, lambida cialotrina, oxicloreto de cobre e hidróxido de cobre apenas com água e em mistura com os adjuvantes polidimetilsiloxano e fosfatidilcoline antes e após chuvas artificais de 10mm, com intervalos de 1, 6, 12 e 24 horas após a pulverização. Os depósitos de caldas remanescentes por área foliar foram analisados por espectrofotometria, considerando um marcador metálico previamente adicionado nas caldas. As variáveis foram submetidas à análise de variância e ao teste de Tukey (P<0,05). As chuvas ocorridas mais próximas do momento das pulverizações resultaram em menores depósitos de calda sobre as folhas de citros. O adjuvante fosfatidilcoline manteve a maior quantidade das caldas sobre folhas de citros, quando da ocorrência de chuvas após a pulverização.

Dynamics of fungicide in chemical control of Phakopsora pachyrhizi in soybean plants subjected to different water regimes / Dinâmica do controle químico de Phakopsora pachyrhizi em plantas de soja submetidas a diferentes regimes hídricos

The objective of this study was to evaluate the dynamics of chemical control of Phakopsora pachyrhizi in soybean plants subjected to different water regimes. The experiment was conducted in the experimental area of Phytus Institute, in Itaara city, central region of Rio Grande do Sul, in 2012/2013 harvest. The experimental design was completely randomized, with four replications in a factorial arrangement (2x6). The first factor was composed of two water regimes: 1) water deficit (5060% of field capacity); 2) no water deficit (90100% of field capacity). The B factor was four time intervals between fungicide application and rainfall simulation (0, 30, 60 and 120 min), a witness to application without rain and a control without fungicide application. In application the active ingredients trifloxystrobin  + prothioconazole (60.0  + 70.0  g i.a.ha1) with the addition of Aureo® at a dose of 0.375 Lpc ha1 were used. The parameters evaluated were the number of days until the first pustule preview of Asian rust, disease severity, yield and grain yield. It was found that the fungicide application in plants under water deficit provides the greatest number of days until the first pustule preview. A  rainfall simulation has great effect in removing fungicides no matter the water regime. The control of P. pachyrhizi in plants under water deficit was effective, resulting in increased productivity.

Objetivou-se com este trabalho avaliar a dinâmica do controle químico de Phakopsora pachyrhizi em plantas de soja submetidas a diferentes regimes hídricos. O experimento foi conduzido na área experimental do Instituto Phytus, no município de Itaara, região central do Rio Grande do Sul, na safra 2012/2013. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições, em arranjo fatorial (2x6). O fator A foi composto por dois regimes hídricos: 1) déficit hídrico (5060% da capacidade de campo); 2) sem déficit hídrico (90100% da capacidade de campo). O fator B consistiu em quatro intervalos de tempo entre a aplicação de fungicidas e a simulação de chuva (0, 30, 60 e 120 min), uma testemunha com aplicação sem chuva e mais uma testemunha sem aplicação de fungicida. Na aplicação foram utilizados os ingredientes ativos trifloxis trobina + protioconazol (60,0 + 70,0 g i.a.ha1) com adição de Aureo® na dose de 0,375 L.p.c ha1. Os parâmetros avaliados foram o tempo decorrido entre a aplicação e o surgimento da primeira pústula de ferrugem asiática, a severidade da doença, a produtividade e a massa de grãos. Verificou-se que a aplicação de fungicida em plantas sob déficit hídrico proporciona o maior número de dias para o aparecimento da primeira pústula. A simulação de chuva tem grande efeito na remoção de fungicidas independentemente do regime hídrico. O controle de P. pachyrhizi em plantas sob déficit hídrico foi eficaz, resultando em incrementos de produtividade.

Dinâmica do controle químico de Phakopsora pachyrhizi em plantas de soja submetidas a diferentes regimes hídricos / Dynamics of fungicide in chemical control of Phakopsora pachyrhizi in soybean plants subjected to different water regimes

Objetivou-se com este trabalho avaliar a dinâmica do controle químico de Phakopsora pachyrhizi em plantas de soja submetidas a diferentes regimes hídricos. O experimento foi conduzido na área experimental do Instituto Phytus, no município de Itaara, região central do Rio Grande do Sul, na safra 2012/2013. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições, em arranjo fatorial (2x6). O fator A foi composto por dois regimes hídricos: 1) déficit hídrico (50-60% da capacidade de campo); 2) sem déficit hídrico (90-100% da capacidade de campo). O fator B consistiu em quatro intervalos de tempo entre a aplicação de fungicidas e a simulação de chuva (0, 30, 60 e 120 min), uma testemunha com aplicação sem chuva e mais uma testemunha sem aplicação de fungicida. Na aplicação foram utilizados os ingredientes ativos trifloxistrobina + protioconazol (60,0 + 70,0 g i.a.ha-1) com adição de Aureo(r) na dose de 0,375 L.p.c ha-1. Os parâmetros avaliados foram o tempo decorrido entre a aplicação e o surgimento da primeira pústula de ferrugem asiática, a severidade da doença, a produtividade e a massa de grãos. Verificou-se que a aplicação de fungicida em plantas sob déficit hídrico proporciona o maior número de dias para o aparecimento da primeira pústula. A simulação de chuva tem grande efeito na remoção de fungicidas independentemente do regime hídrico. O controle de P. pachyrhizi em plantas sob déficit hídrico foi eficaz, resultando em incrementos de produtividade.(AU)

The objective of this study was to evaluate the dynamics of chemical control of Phakopsora pachyrhizi in soybean plants subjected to different water regimes. The experiment was conducted in the experimental area of Phytus Institute, in Itaara city, central region of Rio Grande do Sul, in 2012/2013 harvest. The experimental design was completely randomized, with four replications in a factorial arrangement (2x6). The first factor was composed of two water regimes: 1) water deficit (50-60% of field capacity); 2) no water deficit (90-100% of field capacity). The B factor was four time intervals between fungicide application and rainfall simulation (0, 30, 60 and 120 min), a witness to application without rain and a control without fungicide application. In application the active ingredients trifloxystrobin + prothioconazole (60.0 + 70.0 g i.a.ha-1) with the addition of Aureo(r) at a dose of 0.375 Lpc ha-1 were used. The parameters evaluated were the number of days until the first pustule preview of Asian rust, disease severity, yield and grain yield. It was found that the fungicide application in plants under water deficit provides the greatest number of days until the first pustule preview. A rainfall simulation has great effect in removing fungicides no matter the water regime. The control of P. pachyrhizi in plants under water deficit was effective, resulting in increased productivity.(AU)

Dynamics of fungicide in chemical control of Phakopsora pachyrhizi in soybean plants subjected to different water regimes / Dinâmica do controle químico de Phakopsora pachyrhizi em plantas de soja submetidas a diferentes regimes hídricos

The objective of this study was to evaluate the dynamics of chemical control of Phakopsora pachyrhizi in soybean plants subjected to different water regimes. The experiment was conducted in the experimental area of Phytus Institute, in Itaara city, central region of Rio Grande do Sul, in 2012/2013 harvest. The experimental design was completely randomized, with four replications in a factorial arrangement (2x6). The first factor was composed of two water regimes: 1) water deficit (5060% of field capacity); 2) no water deficit (90100% of field capacity). The B factor was four time intervals between fungicide application and rainfall simulation (0, 30, 60 and 120 min), a witness to application without rain and a control without fungicide application. In application the active ingredients trifloxystrobin  + prothioconazole (60.0  + 70.0  g i.a.ha1) with the addition of Aureo® at a dose of 0.375 Lpc ha1 were used. The parameters evaluated were the number of days until the first pustule preview of Asian rust, disease severity, yield and grain yield. It was found that the fungicide application in plants under water deficit provides the greatest number of days until the first pustule preview. A  rainfall simulation has great effect in removing fungicides no matter the water regime. The control of P. pachyrhizi in plants under water deficit was effective, resulting in increased productivity.(AU)

Objetivou-se com este trabalho avaliar a dinâmica do controle químico de Phakopsora pachyrhizi em plantas de soja submetidas a diferentes regimes hídricos. O experimento foi conduzido na área experimental do Instituto Phytus, no município de Itaara, região central do Rio Grande do Sul, na safra 2012/2013. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições, em arranjo fatorial (2x6). O fator A foi composto por dois regimes hídricos: 1) déficit hídrico (5060% da capacidade de campo); 2) sem déficit hídrico (90100% da capacidade de campo). O fator B consistiu em quatro intervalos de tempo entre a aplicação de fungicidas e a simulação de chuva (0, 30, 60 e 120 min), uma testemunha com aplicação sem chuva e mais uma testemunha sem aplicação de fungicida. Na aplicação foram utilizados os ingredientes ativos trifloxis trobina + protioconazol (60,0 + 70,0 g i.a.ha1) com adição de Aureo® na dose de 0,375 L.p.c ha1. Os parâmetros avaliados foram o tempo decorrido entre a aplicação e o surgimento da primeira pústula de ferrugem asiática, a severidade da doença, a produtividade e a massa de grãos. Verificou-se que a aplicação de fungicida em plantas sob déficit hídrico proporciona o maior número de dias para o aparecimento da primeira pústula. A simulação de chuva tem grande efeito na remoção de fungicidas independentemente do regime hídrico. O controle de P. pachyrhizi em plantas sob déficit hídrico foi eficaz, resultando em incrementos de produtividade.(AU)