ABSTRACT Seasonal changes in agricultural soil use due to agroclimatic conditions affect the water cycle in watersheds. This study aimed to understand the temporal variation of runoff inherent to the seasonal occupation dynamics of the agricultural soil in the basin that drains the upper valley of the Marrecas River, upstream of the urban perimeter of Francisco Beltrão, PR. The effects of runoff were verified through flow peaks simulated by the HEC-HMS model in twelve monthly soil use scenarios, under seven precipitation return periods. The results indicated a strong relationship between bare soil and flow peaks, temporally delimiting April and March as the largest runoff generators and January and August as the smallest ones. The ratio quantified by rates of increase in flow peaks ranging from 0.78 to 1.64 m3 s−1 per km2 of bare soil. In addition, the survey of historical precipitation data also warns of the generation of large runoff volumes in October. Therefore, the strong correlation between the increase in flow peaks and occupation by bare soil can be quantified with good precision, but it is also necessary to consider historical precipitation records to understand the temporal distribution of runoff and flood risks.

ABSTRACT Analyzing the physical-chemical and biological characteristics allows the evaluation of the water quality of a water body. Thus, the objective of this study was to determine the water quality index of the Passaúna and Piraquara rivers, as well as to apply statistical quality control methodologies to evaluate the data resulting from the monitoring of water quality. Therefore, a database with physico-chemical and microbiological parameters of the Passaúna and Piraquara rivers, a watershed of the Iguaçu River, belonging to the cities of Araucária and Piraquara, respectively Paraná, Brazil, was used to carry out the research. The water quality index was determined with the time series and, subsequently, these data were submitted to the statistical control of the process, with the control charts of individual Shewhart, EWMA and CUSUM, in addition to the development of the process capacity index. The WQI detected that the rivers remained in average quality until the year 2000, however, from that year it was possible to see a decreasing trend in the water quality of the evaluated rivers. The control charts of Shewhart, EWMA, CUSUM and the process capability index were able to identify the decreasing trend in water quality, demonstrating that they are fast and efficient techniques for the evaluation of water quality control.

ABSTRACT The contamination of aquatic environments with chemical trace elements can be evaluated by their accumulation in sediments of the water body. Studies on mercury require the use of exclusive extraction techniques that have relatively high costs when compared to the analysis of other trace elements. This study was conducted aiming at determining the mercury concentration in sediments of the Upper Parnaíba River basin, located in a region of agricultural expansion between the states of Piauí and Maranhão. The sediment was collected at 12 sites in the basin. After drying, the quantification of total mercury was performed by the Zeeman atomic absorption spectrometry coupled to a pyrolysis reactor. Mercury concentrations in sediments of the Parnaíba River ranged from 4.2 to 58.5 ng g−1 and presented a low probability of adverse effects on biota. Mercury had no correlation with the variables clay, silt, sand, total organic carbon, iron, and aluminum, demonstrating its possible anthropogenic origin. Although mercury concentrations have a low probability to disturb the balance of the local ecosystem, there is a need for monitoring the region in order to quantify the risks to biota and human health.

ABSTRACT Many studies have determined the concentration of trace elements in river sediments in Brazil. Notwithstanding, mercury assessments are scarce, especially because of exclusive extraction techniques and expensive analysis techniques. Still, this element is known for its toxicity, persistence, and bioaccumulation, making its presence in the environment an important factor for biota and human health. For this reason, the objective of this study was to determine the mercury concentration in the sediment of the Pelotas River basin, located on the border of the states of Santa Catarina and Rio Grande do Sul. The sediment was collected at eight locations of the Pelotas basin and, after drying, the mercury was quantified by atomic absorption spectrometry based on the Zeeman-background correction, coupled to a pyrolysis reactor. The mercury concentrations in the sediments of the Pelotas River varied from 40.5 ng g-1 to 62.0 ng g-1 and presented a positive correlation with the fraction of silt and clay. The concentrations of mercury found in sediments of the Pelotas River basin have a low probability of negatively affecting the biota. Nonetheless, given the persistence and bioaccumulation potential of this element, the aforementioned region needs further studies to quantify the risks it may cause on the local biota and human health.

ABSTRACT Aquatic sediments are widely used for the evaluation of anthropogenic contamination due to their ability to adsorb particles and contaminants, making them historical environmental archives. Therefore, the objective was to evaluate the contamination of the Pelotas River sediments, at the border between the states of Santa Catarina and Rio Grande do Sul, by organochlorine and organophosphorus compounds, determining the ecological risk. The evaluation was carried out with quarterly sediment collections in 8 points, totalizing four campaigns within one year, with the aid of the Peterson dredger. Among organochlorines, p'p'DDT stands out regarding environmental persistence, representing 53.23% of the contaminated samples, with values varying up to 0.158 ppb. As for the organophosphates, Methyl Parathion obtained larger representation with 48.4% of the contaminated samples, with concentrations ranging up to 2.42 ppb. The ecological risk of selected organochlorines demonstrated no problems associated with the biota. Regarding the organophosphates studied, Disulfoton presented a risk factor with significant potential for adverse effects on organisms. Therefore, the need for monitoring and sustainability in the use and application of pesticides is well known, aiming at environmental quality and the preservation of natural resources.

ABSTRACT The knowledge of pesticide residual concentrations in the environment is important to understand the threats to the environment and human health, especially when natural resources are used for human consumption. In this context, this study aimed to assess the potential ecological risk and respective sources of sediment contamination by organochlorine and organophosphorus pesticides. The study site was an urban lake located in Cascavel city, western Paraná state, Brazil, where the history of land use and occupation in the urban environment is typically agricultural. Surface sediment samples were collected every three months from April 2010 to June 2013 at five different collection points, totaling 65 samples. Analyses showed that contamination by organochlorine pesticides is related to agricultural activities in the past, with a low ecological risk to benthic organisms. Conversely, organophosphorus pesticides presented a recent and continuous contamination from urban activities, with a risk coefficient, especially for disulfoton, indicating a significant potential adverse effect on organisms. However, in general, the obtained results did not indicate an immediate risk to public health.

ABSTRACT Geochemical background establishment is indispensable to determine the actual state of contamination of soils and sediments. However, no scientific consensus exists regarding the methodology for determining these values. In this context, this study aimed to establish the geochemical background in an Oxisol (Rhodic Hapludox) by means of an integrated method that uses direct and indirect soil analyses to identify the most appropriate calculation methodology. Soil samples were collected in a permanent preservation area of the Cascavel River watershed, PR, Brazil. The elements Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn present in soil samples were quantified by flame atomic absorption spectrometry. The use of a permanent preservation area is the most effective method to establish the geochemical background in the Cascavel River watershed. However, soil chemical element concentrations have spatial variability and dependence, requiring the application of non-parametric statistical methods based on third quartile and median for establishing the geochemical background.

ABSTRACT Hog raising generates a large amount of residues that is commonly discarded into the soil as fertilizer even with environmental risks. In this context, the aim of this study was to assess the application effects of different doses of swine wastewater (SW) associated with mineral fertilization on the abundance and diversity of organisms of soil meso- and macrofauna in two soybean crops. Treatments consisted of four doses (0, 100, 200, and 300 m3 ha−1) of SW with or without mineral fertilization in two soybean crop, totaling 24 experimental units. Soil meso- and macrofauna were sampled using pitfall traps installed at each plot. Samples were sorted and the organisms were separated and identified. The highest abundances were found between groups of springtails and spider mites. Soil meso- and macrofauna differed between soybean crops influenced by soil physical and chemical parameters. Doses of swine wastewater between 0 and 300 m3 ha−1 and mineral fertilization do not have effects on ecological indices of soil meso- and macrofauna. However, periodic applications over time change soil physicochemical variables, which may lead to negative effects in the long term.

Os resíduos gerados em suinoculturas possuem alto potencial poluidor, porém, devido à grande carga orgânica, apresenta-se como boa opção na fertilização de solos agrícolas. O objetivo deste trabalho foi estudar os efeitos ambientais decorrentes do uso de águas residuais de suinocultura em diferentes solos usando como bioindicador minhocas da espécie Eisenia andrei, por meio dos parâmetros de letalidade, fuga e reprodução. Estudou-se a aplicação de água residual de esterqueira e biodigestor em quatro doses (0, 100, 200 e 300 m³ ha-1) em três solos: Latossolo Vermelho distroférrico típico, Nitossolo Vermelho eutroférrico e Solo Artificial Tropical. Os resíduos estudados não provocaram qualquer letalidade nem fuga. Nos testes de reprodução, na maioria dos experimentos as parcelas com tratamentos obtiveram valores médios de juvenis eclodidos acima das parcelas controlo. A aplicação de água residual de esterqueira e biodigestor até a dose de 300 m³ ha-1 não afeta negativamente as populações de minhocas nos três solos analisados.

The waste generated by pig farmings has high toxic potential, however, its high organic load, makes them a good product for fertilization of agricultural soils. The aim of this work was to study the environmental effects arising from the use of swine wastewater using as bioindicators earthworms of the species Eisenia andrei through the parameters of lethality, avoidance and reproduction. We studied the application of biodigester wastewater and manure storage tanks wastewater in four doses (0, 100, 200 and 300 m³ ha-1) in three different soils (Oxisol, Kandiudox and Artificial Tropical Soil). The studied wastes did not cause any lethality or escape. The reproduction test showed, in most of the experiments that the plots with treated soil had an average number of hatched juveniles above those of control plots. The application of biodigester wastewater and manure storage tanks wastewater up to the dose of 300 m³ ha-1 does not negatively affect earthworm populations in the three soils analyzed.

Potted gerbera is an ornamental plant that is widely commercialized in Brazilian markets. However, information on cultivation techniques is needed to meet growing demand, especially with regard to fertilization. This study was carried out to assess the growth of potted gerbera, Florist Red Black cultivar, with mineral and organic fertilization. The experiment was conducted in a greenhouse located at UNIOESTE - Cascavel Campus - PR. The experimental design was composed of randomized blocks with four replicates and five treatments. Treatments were defined according to the fertilization source, which were mineral (NPK) and organic. Organic fertilizers were obtained by diluting in water four organic composts from agroindustrial-waste composting processes. After obtaining composts, water dilution was performed, adjusting the nutritive solution electrical conductivity values. Gerbera plants were assessed fortnightly (0, 14, 28, 42, and 56 days after acclimatization) for leaf area and shoot dry matter, which were adjusted for time using the ANACRES program to obtain the leaf area ratio (LAR), relative growth rate (RGR), and net assimilation rate (NAR). Fifty-six days after acclimatization, plants were assessed for number of leaves, plant diameter, leaf area, leaves and inflorescences dry phytomass, stem height, head diameter, and stem diameter. The highest relative growth rates were obtained in plants grown with organic compost in treatment 3. However, the net assimilation rate, which indicates dry matter conversion efficiency, was highest in plants with chemical fertilization (treatment 1).

La gerbera es una planta ornamental que es ampliamente comercializada en el mercado brasileño. Sin embargo, para satisfacer la creciente demanda, es necesario contar información sobre las técnicas de cultivo, destacando la fertilización. Este trabajo se realizó con el fin de evaluar el crecimiento de gerbera en maceta, cultivar Floristería Rojo Negro, fertilizado con un producto mineral y fertilización orgánica. El experimento se realizó en un invernadero ubicado en UNIOESTE - Cascavel Campus - PR. El diseño experimental fue de bloques al azar, con cuatro tratamientos y cinco repeticiones. Los tratamientos se definieron de acuerdo a la fuente de la fertilización mineral (NPP) y orgánico. La fertilización orgánica se obtuvo diluyendo cuatro compuestos orgánicos de proceso de compostaje de residuos agroindustriales en agua. Después de la obtención de estos compuestos, se ajustaron los valores de conductividad eléctrica de la solución nutritiva. En las plantas de gerbera se evaluó cada dos semanas (0, 14, 28, 42 y 56 días después de la aclimatación), el área foliar y la materia seca, que se ajusta en relación con el tiempo con el programa ANACRES, con el fin de obtener la relación de área foliar (LAR), tasa de crecimiento relativo (RGR) y la tasa de asimilación neta (NAR). 56 días después de la aclimatación, se evaluó en el número de hojas, diámetro de la planta, área foliar, hojas e inflorescencias de fitomasa seca, altura de tallo, diámetro de la cabeza y el diámetro del tallo. Las mayores tasas de crecimiento relativo se obtuvieron en plantas realizados con abono orgánico en el tratamiento 3. Sin embargo, la tasa de asimilación neta, que indica la eficiencia de conversión de materia seca, fue mayor en las plantas con la fertilización química, en el tratamiento 1.

RESUMO A aplicação de água residuária de suinocultura (ARS) em solos agrícolas pode gerar impactos na comunidade microbiana do solo, quando realizada em longo prazo. O objetivo deste trabalho foi avaliar possíveis alterações na comunidade bacteriana do solo após oito anos de aplicação contínua de água residuária de suinocultura. As doses de água residuária (0; 100; 200 e 300 m3 ha-1 ), aplicadas desde o início do experimento, foram combinadas com a presença ou a ausência de adubação recomendada. No solo, foram feitas três coletas em cada parcela para a determinação da respiração basal, biomassa microbiana e quociente metabólico, análise de DGGE, correlação entre as condições químicas do solo e a atividade microbiana na comunidade bacteriana do solo. Alterações significativas na estrutura da comunidade microbiana do solo, com a aplicação de água residuária de suinocultura, foram observadas. Doses maiores de ARS (200 e 300 m3 ha-1) influenciaram de forma significativa (p<0,05) e privilegiaram a permanência de alguns grupos específicos de bactérias.

ABSTRACT Swine wastewater (SW) application in agricultural soils may affect its microbial community in a long term. The objective of this study was to evaluate prospective changes in soil bacterial community after eight years continuous application of swine wastewater. The wastewater doses tested were 0; 100; 200 and 300 m3 ha-1, being applied from the beginning of the experiment and with or without recommended fertilization. Three soil samples were taken from each plot for determinations of basal respiration, microbial biomass and metabolic quotient. We also performed DGGE analysis and made a correlation between soil chemical conditions and microbial activity. Microbial community underwent significant structural changes from swine wastewater applications. Higher SW doses (200 and 300 m3 ha-1) influenced significantly (p <0.05) and benefitted certain bacteria groups.