Objetivou-se avaliar, neste trabalho, os efeitos da irrigação com água de esgoto doméstico sobre as variáveis de crescimento e produtividade da mamoneira, genótipo EBDA MPB 01, em condições de campo. A pesquisa foi realizada no período de dezembro de 2009 a junho 2010, na Universidade Federal do Recôncavo da Bahia, Campus de Cruz das Almas. Foram estudadas quatro diferentes proporções de diluição de esgoto doméstico tratado em comparação com o tratamento testemunha (adubação e irrigação convencional), da seguinte forma: T1 - 100% do efluente tratado; T2 - 75% do efluente tratado mais 25% de água de poço artesiano; T3 - 50% do efluente tratado mais 50% de água de poço artesiano; T4 - 25% do efluente tratado mais 75% de água de poço artesiano e T5 - manejo convencional (adubação química e irrigação suplementar com água de poço artesiano). O delineamento experimental foi em blocos casualizados (DBC) com quatro blocos cada tratamento, constituindo de 20 parcelas experimentais. A produtividade da mamoneira não apresentou diferença estatística entre os tratamentos. O uso de água residuária de esgoto doméstico na cultura da mamoneira, não afetou as variáveis de crescimento analisadas.

SUMMARYMicrobial processes have been used as indicators of soil quality, due to the high sensitivity to small changes in management to evaluate, e.g., the impact of applying organic residues to the soil. In an experiment in a completely randomized factorial design 6 x 13 + 4, (pot without soil and residue or absolute control) the effect of following organic wastes was evaluated: pulp mill sludge, petrochemical complex sludge, municipal sewage sludge, dairy factory sewage sludge, waste from pulp industry and control (soil without organic waste) after 2, 4, 6, 12, 14, 20, 28, 36, 44, 60, 74, 86, and 98 days of incubation on some soil microbial properties, with four replications. The soil microbial activity was highly sensitive to the carbon/nitrogen ratio of the organic wastes. The amount of mineralized carbon was proportional to the quantity of soil-applied carbon. The average carbon dioxide emanating from the soil with pulp mill sludge, corresponding to soil basal respiration, was 0.141 mg C-CO 2 100 g -1 soil h -1 . This value is 6.4 times higher than in the control, resulting in a significant increase in the metabolic quotient from 0.005 in the control to 0.025 mg C-CO 2 g -1 C mic h -1 in the soil with pulp mill sludge. The metabolic quotient in the other treatments did not differ from the control (p < 0.01), demonstrating that these organic wastes cause no disturbance in the microbial community.Index terms: microbial respiration, microbial carbon, microbial nitrogen, metabolic quotient, organic sludge.(1) Part of the dissertation of the first author, for a post-graduate degree in Agricultural Sciences, 2, 4, 6, 12, 14, 20, 28, 36, 44, 60, 74, 86

Sweet pepper plants were grown using a Nutrient Film Technique (NFT) hydroponic system. This study aimed to evaluate the effect of using brackish water on fruit production. The experiment was carried out in a randomized block design with seven treatments and five replications. The electrical conductivity of the water was 0.29, 1.39, 2.75, 4.49, 5.90, 6.76, and 7.09 dS m -1 in the treatments; this water was used for both the nutrient solution preparation and replenishment of crop evapotranspiration. The plant parameters: fruit diameter, fruit length, number of fruits per plant, mean fruit weight, total fruit weight per plant and fruit length/diameter ratio were evaluated 69 days after the transplanting. The use of brackish water with high electric conductivity values did not directly interfere with the sweet pepper production in NFT hydroponic systems, as long as these values did not exceed the sweet pepper salt tolerance of 1.5 to 1.8 dS m -1 .Additional key words: soilless cultivation, semiarid, environmental protection, water reuse. RESUMENLas plantas de pimiento dulce se cultivaron utilizando un sistema hidropónico Nutrient Film Technique (NFT). Su objetivo fue evaluar el efecto del uso de agua salobre en la producción de fruta. El experimento se The increasing demand for water resources in recent decades has led to the search for more water-efficient techniques, as well as the rational use of water that is not desirable for drinking. The agricultural production sector puts the highest pressure on water resources. According to Chartzoulakis and Bertaki (2015), of the total annual volume of estimated water diversion worldwide, agricultural production currently uses about 70%, mainly for irrigation.In this context, according to some authors (Dias et al., 2010;Cosme et al., 2011;Santos Júnior et al., 2015), hydroponic agriculture is a strong ally as a mitigating technology against the quantitative and qualitative depletion scenario of water resources for the following reasons. Firstly, this approach favors water-efficient applications in agriculture.The other reason involves the use of water that is considered marginal, such as brackish water. Alves et al. (2011) reported that, as hydroponic cultivation frequently assumes a matric potential equal to zero because of the saturation of plants, the crop response to salinity increases, ascompared to the conventional cultivation system. Moreover, the authors pointed out that the drainage and irrigation system (Nutrient Film Technique) enables the appropriate use of mineral salts at the end of production. Numerous studies have shown (Paulus et al., 2010;Soares et al., 2010;Alves et al., 2011;Maciel et al., 2012;Sarmento et al., 2014) promising results using brackish water in the hydroponic cultivation of vegetables and some ornamental plants.Moderately sensitive to salinity (Ayers and Westcot, 1985;Kurunc et al., 2011;Maia et al., 2017), bell peppers (Capsicum annuum L.) are one of the most widespread vegetables that are consumed fresh in Brazil. According to A...

In semi-arid regions of developing countries worldwide it is necessary to develop low cost technology methods to acquire new water supplies. The objective was to evaluate the changes in the attributes of soil quality irrigated with treated sewage effluent. The treatments consisted of applying treated sewage effluent (TSE) and underground well water (UWW) in the following proportions: E 0% (chemical fertilization and UWW), E 25% (25% TSE and 75% UWW), E 50% (50% of TSE and UWW), E 75% (75% TSE and 25% UWW) and E 100% (100% TSE). The sodium content did not differ significantly among the treatments, but the sodium input diminished as the percentage of residuary water in the irrigation grew. There was a greater increment of microbial biomass carbon in the E 25% treatment. On the other hand, although treatments E 50% to E 100% have a greater nutrient input, they were no different from control treatments performed with well water. Treated domestic sewage effluent at a proportion of 25% is a feasible alternative for castor bean irrigation, however it is necessary to monitor the possible changes in the soil attributes over successive crops. Microbial attributes can be used as a quick, good indicator of changes in soil quality.