Cláudia Miranda et al.RESUMO: A ação antrópica ao longo dos anos, no entorno da microbacia do rio Parafuso, ocasionou impactos ambientais adversos sobre os recursos hídricos. Este estudo tem como objetivos avaliar a qualidade da água do rio Parafuso com base nos atributos físicos, químicos e microbiológicos e identificar os diferentes usos da água pela comunidade local, a fim de obter informação que possa subsidiar propostas para o manejo sustentável da microbacia. Para a avaliação da qualidade da água foram realizadas quatro campanhas, considerando a sazonalidade, com 19 pontos de amostragem. Foram realizadas entrevistas, observação direta e aplicados questionários para coletar os dados sobre os diferentes usos da água pela população local. Os resultados revelam a multifuncionalidade dos rios. Os índices do Ferro e E. coli, em alguns pontos amostrais, ultrapassam os limites exigidos pela legislação, o que denota o comprometimento da qualidade da água na referida microbacia para os diversos usos domésticos.Palavras-chave: Amazónia, ação antrópica, microbacia, recursos hídricos, qualidade da água. ABSTRACT: The anthropic action over the years on surroundings of Parafuso river microbasin caused adverse environmental impacts on water resources. This study aims to evaluate the water quality of Parafuso river and its tributary pass rote, based on physical, chemical and microbiological attributes, as well as identify the different uses of water by the local community, in order to obtain in formations to

The root-lesion nematode Pratylenchus spp. causes a high-severity disease, promoting high economic losses in various crops of agricultural importance. The nematode control is difficult, especially after introduction into the area. Studies on the migration of this parasite in the soil are scarce. However, understanding nematode behavior in the soil is fundamental to increase the efficiency of management practices, especially in irrigated agriculture. This study aimed to evaluate the influence of water flow and plant stimulus on Pratylenchus coffeae mobility in segmented soil columns. The columns were segmented into 11 rings of 1 cm long filled with washed sand, one of the ends exposed to a bait, and submitted to flows of 0, 3, 7 cm3/min of water. Baits for nematode attraction and repelling consisted of sectioned tubers of yam (Dioscorea cayennensis) and cut leaves of neem (Azadirachta indica), respectively, and the absence of baits as the control. Nematodes were injected into the central segment of the column, and migration and presence in water leaching were determined five days after soil infestation. Mobility of P. coffeae varied with water flow and bait type. In the absence of water flow, nematodes migrated in the opposite direction to the neem baits, but migration was well distributed in the presence of yam baits, with specimens present in all column segments. The nematode had significantly higher resistance to water flow of 3 cm3/min in the presence of yam baits. No nematodes were found in the water leached at flows of 3 and 7 cm3/min in the absence of bait. Key words: Azadirachta indica. Dioscorea cayennensis. Lesion nematode. Soil dispersion.

No abstract

Knowledge of the total content of soluble salts present in the water and the behavior of their dominant ions allows the use and management more adequately in use for irrigated agriculture. In this context, this study aimed to evaluate the dynamics of salts in surface and ground water for irrigation purposes in three water systems in the Brazilian semiarid region: the Trussu weir, the perennial Excerpt from Trussu river and wells located along the river valley perennial. The study area is located in the basin of Alto Jaguaribe in the city of Iguatu, Ceará, Brazil. Samples were collected from March 2013 to March 2015, a total of 10 collections in 14 sampling stations. The parameters monitored were: sodium, calcium, magnesium, bicarbonate, carbonate, chloride and sulfate, the sodium adsorption normal ratios were calculated and corrected, besides the electric conductivity. Then applied the Piper diagram in the definition of the water classes. The waters were classified as chlorinated contains calcium, bicarbonated contains calcium, bicarbonated sodium for surface and ground water and chlorinated sodic into groundwater. Regarding the classification for irrigation results showed that surface water showed low risk of generating salinity problems, since the underground showed a risk of medium to high risk of causing salinity. As for sodicity surface water present no problems, since the underground are with sodicity problems can only be used on soils with adequate management of salts.

No abstract