R ESU M OObjetivou-se, com esse trabalho, avaliar o desempenho hidráulico do gotejador Katif, da marca Plastro Brasil, tipo externo, autocompensante, utilizando-se efluentes oriundos de três diferentes formas de tratamento de esgoto doméstico. O experimento foi desenvolvido em condições de campo e laboratório. Os ensaios de campo consistiram na avaliação de um sistema de irrigação por gotejamento, sendo determinados, em três ocasiões, os testes de uniformidade. Em laboratório objetivou-se comparar o desempenho hidráulico dos emissores usados com um lote de emissores novos, em quatro faixas de pressão: 100, 150, 200 e 250 kPa. Foram obtidos os valores dos coeficientes de uniformidade de distribuição (CUD), de uniformidade estatística (CUE), e coeficiente de variação do fabricante (CVf). Os resultados obtidos permitiram concluir que a utilização de esgoto doméstico tratado por decanto digestor associado a um filtro digestor e a uma lagoa de estabilização, proporcionou os melhores resultados de uniformidade de distribuição e que, de modo geral, ocorreram perdas no desempenho hidráulico dos emissores com o uso contínuo de águas provenientes de estações de tratamento de esgoto doméstico. Palavras-chave: reúso, entupimento, desempenho hidráulicoPerformance of auto compensating drippers with different effluents of domestic sewage A B ST R A C T This study had the objective of evaluating the hydraulic performance of dripper Katif, brand Plastro Brazil, external type, auto compensating using effluent from three different treatments of domestic sewage. The experiment was conducted under field and laboratory conditions. The field test consisted in the evaluation of a drip irrigation system by uniformity tests which were conducted on three occasions. In the laboratory, the study aimed to compare the hydraulic performance of used emitters with a lot of new emitters in four pressure ranges: 100, 150, 200 and 250 kPa. The values were obtained for the Christiansen Uniformity Coefficient (CUC), Distribution Uniformity Coefficients (CUD), and of Manufacturer Variation Coefficient (CVf). The results showed that the use of domestic sewage treated with decant digester associated with a filter digester and a stabilization pond provided the best results in distribution uniformity and, in general, the continuous use of wastewater provided losses in the hydraulic performance of emitters.

Resumo -), um efluente do processo de dessalinização. Estas águas foram combinadas em seis tratamentos resultantes da sua utilização alternada para preparar a solução nutritiva (SN) e/ou substituir as perdas por evapotranspiração (ETc). O experimento foi conduzido em casa de vegetação na região semiárida de Pernambuco, utilizando 48 unidades experimentais em blocos casualizados em esquema fatorial 6x2 com quatro repetições. O rendimento da alface (massa de matéria fresca) foi maior nas condições do Floating. O uso exclusivo da água do poço profundo e do rejeito de dessalinizadores diminuiu 22,7 e 39,6% a produção de alface, respectivamente. Para uma melhor combinação de águas doces e salobras, o uso de água salobra para repor a perda por ETc pode aumentar a produção de alface em relação ao uso dessas águas para preparar a SN, estes resultados foram registrados para a água do poço profundo e o rejeito. Palavras-chave -Recursos hídricos. Água salobra. Semiárido.Abstract -Plants of lettuce cv. Elba were grown under two hydroponic systems, Floating and NFT, aiming to evaluate three water resources: natural brackish water (2,47 dS m -1 ) obtained from a deep well; fresh water (0,11 dS m -1 ) produced by reverse osmosis desalination; and reject brine (5,15 dS m -1 ), a wastewater from desalination process. These waters were combined in six treatments resulted from their alternated use to prepare nutrient solution (NS) and/or replace the evapotranspiration loss (ETc). The experiment was carried out under a greenhouse condition in the semiarid region of Pernambuco State, Brazil; 48 experimental units were used for both hydroponic systems. The lettuce yield (shoot fresh matter) was higher under Floating conditions. The single use of deep well water and reject brine decreased 22.7 and 39.6% the lettuce yield, respectively. For a better combination of fresh and brackish waters, the use of brackish water to replace ETc loss may increase the lettuce yield in comparison to use these waters to prepare the NS; this result was registered for deep well water and reject.

The analysis of plant response to the cationic variability of the waters, in addition to the osmotic component, is indispensable in the context of salt stress. Thus, between October 2017 and February 2018, in Recife, PE, Brazil (8° 1’ 7” S and 34° 56’ 53” W, and altitude of 6.5 m), the present study was carried out to evaluate the water relations of parsley plants (Petroselinum crispum), cv. Graúda Portuguesa, cultivated in brackish nutrient solutions (electrical conductivities of 1.7, 2.7, 3.7, 4.7, 5.7 and 6.7 dS m-1) prepared in waters with different cationic natures (NaCl, CaCl2, KCl and MgCl2). The experimental design was completely randomized, in a 6 x 4 factorial scheme, with five repetitions, and five plants per plot. Two experiments were conducted sequentially under this statistical design; in the first, the evapotranspired depth was replaced with supply water (0.12 dS m-1) and in the second, with the respective brackish water. The increment in nutrient solution salinity influences the fresh and dry biomass and the percentages of total, shoot and root dry masses, and this increment led to different behavior in parsley physiology under the different cationic natures of the water, being less harmful with the use of supply water to replace the evapotranspired depth and with CaCl2 water with electrical conductivity above 5.7 dS m-1, in the replacement with brackish water.

RESUMO

This study aimed to evaluate the dry matter production and nutrient accumulation of coriander (Coriandrum sativum L.) under pulse and continuous fertigation depths. The experiment was conducted in randomized blocks in 2 x 5 factorial arrangement, with three replicates. Treatments consisted of two types of fertigation application (pulse and continuous) and five fertigation depths (40, 60, 80, 100 and 120% of crop evapotranspiration – ETc). Highest accumulations of dry matter, N, P, K, Fe, Mn, Cu and Zn were obtained with pulse fertigation. Pulse fertigation combined with depths lower than 100% ETc led to highest accumulations of K, Mn, Cu and Zn. The accumulation of nutrients decreased in the following order: K > N > Ca > P > Mg > S > Fe > Mn > Zn > Cu.