Water-Retaining Polymer and Planting Pit Size on Chlorophyll Index, Gas Exchange and Yield of Sour Passion Fruit with Deficit Irrigation.

Water availability is a limiting factor for the cultivation of sour passion fruit. Soil management techniques and the use of water-retaining polymers can increase soil water retention, reducing the frequency of irrigation in the crop. In this context, the objective of the research was to evaluate the gas exchange, the chlorophyll index, and the yield of the sour passion fruit cv. BRS GA1 as a function of irrigation depths, pit volumes, and doses of water-retaining polymer. The experiment was carried out in randomized blocks, in plots subdivided in a 2 × (2 × 5) arrangement, with irrigation depths of 70 and 100% of the crop evapotranspiration (ETc) as the main plot, the subplots with the volumes of pit of 64 and 128 dm3, and doses of the water-retaining polymer of 0, 0.5, 1.0, 1.5, and 2.0 g dm-3. The interaction of irrigation depths × pit volumes × doses of water-retaining polymer influences chlorophyll indexes, gas exchange, and water productivity, with positive impacts on yield of the sour passion fruit. The water depth of 70% of ETc increased the yield of sour passion fruit, in pits of 64 dm3. The application of doses of up to 1.1 g dm-3 of the water-retaining polymer and irrigation with water of 70% of ETc is recommended, and a dose of 2.0 g dm-3 of the water-retaining polymer in a pit volume of 128 dm3, associated with an irrigation depth of 100% ETc causes stress in sour passion fruit plants due to excess water.

Productive characteristics of sunflower genotypes irrigated with different levels of saline water

Sunflower is suitable for family farmers from Northeast Brazil who are benefited by the production of grain and oil and is adequate for crop rotation and for honey production. The need for irrigation in this region leads to the realization of this study for evaluating the production components of four sunflower genotypes irrigated with different levels of water salinity. The study was carried out in the municipality of Remigio, Paraíba, Brazil, using a randomized block with split plots experimental design in a 5 x 4 factorial arrangement. Treatments consisted of five electrical conductivity levels of the irrigation water at 25 °C (L1 - 0.14 (reservoir water), L2 - 1.50, L3 - 2.50, L4 - 3.50, and L5 - 4.50 dS m- 1), and four sunflower genotypes (C1 - Embrapa 122-V2000, C2 - Olisun 03, C3 - AG 963, and C4 - Multissol) with three replicates. The irrigation water salinity levels tested did not influence the variables studied. Different values of the variables among sunflower genotypes were due to characteristics inherent to each genotype. Sunflower genotype Olisun 03 presented the highest oil content, while the lowest content was observed in Multissol.

Chemically enhanced primary treatment of dairy wastewater using chitosan obtained from shrimp wastes: optimization using a Doehlert matrix design.

Dairy operations generate large volumes of polluted wastewater that require treatment prior to discharge. Chemically enhanced primary treatment (CEPT) is a widely utilized wastewater treatment strategy; but it requires the use of non-biodegradable coagulants that can lead to toxic-byproducts. In this study, chitin from shrimp shell waste is extracted and converted into chitosan. Chitosan was demonstrated to be a natural, low-cost alternative coagulant compatible with the CEPT. Following treatment, dissolved air flotation allowed for the removal of turbidity, COD, and UV254 from the synthetic dairy effluent (SDE). Doehlert matrix was used to optimize the chitosan dosage and pH of the CEPT; as well as to model the process. The mechanisms behind the coagulation-flocculation were revealed using zeta potential analysis. FTIR spectroscopy was utilized to confirm the functional groups present on the chitosan. Chitosan with a degree of deacetylation equal to 81% was obtained. A chitosan dose of 73.34 mg/L at pH 5.00 was found to be optimal for the removal of pollutants. Removals of COD, turbidity and UV254 were 77.5%, 97.6%, and 88.8%, respectively. The amount of dry sludge generated to treat 1 m³ of SDE was 0.041 kg. Coagulation-flocculation mechanisms involved in chitosan-mediated treatment of SDE involve the neutralization of electrostatic charges carried on the amine groups present in cationic chitosan at pH 5.00. Doehlert matrix proved to be a useful tool in optimizing parameters throughout the coagulation-flocculation process. Chitosan from shrimp waste is a low-cost, eco-friendly coagulant alternative for the removal pollutants from dairy effluent using the CEPT.

Translocation factor of heavy metals by elephant grass grown with varying concentrations of landfill leachate.

The aim of this study is to obtain the translocation factor by application of landfill leachate (LL) diluted in public irrigation water (IW). Pennisetum purpureum Schum (elephant grass) was cultivated for 83 days in an experimental water reuse unit. The present work was developed at the Experimental Water Reuse Unit (UERA), on the UFERSA campus in Mossoró, RN, Brazil. Plot irrigation was based on water balance and crop evapotranspiration (ETc). The concentration in the plant tissue (root and leaf) of the following heavy metals was measured to determine the respective translocation factors: manganese (Mn), zinc (Zn), copper (Cu), nickel (Ni), cadmium (Cd), and lead (Pb). The experiment was set up in a randomized block design with five treatments (T1, plots irrigated only with IW; T2, 50% of LL dose plus IW; T3, 100% of LL dose plus IW; T4, 150% of LL dose plus IW; and T5, 200% of LL dose plus IW) and five replications. All treatments received LL plus IW depth of 491.02 mm for 83 days of P. purpureum cultivation. The data obtained were submitted to multivariate analysis plus the nonparametric Kruskal-Wallis test to compare the means. Pennisetum purpureum showed a potential to accumulate metals in its tissues, mainly Mn, Zn, and Cu. The treatments that most favored the extraction of these metals were T2 and T5; in this sense, P. purpureum was not efficient in translocating heavy metals, since the translocation factor observed in all treatments was below 1.0, indicating that the species used extract heavy metals from soil solution and keeps in yours roots. This suggests planting P. purpureum may not be a viable option to remediate environments highly contaminated with heavy metals.

Growth and biomass production of prickly pear in the second cycle irrigated with treated domestic sewage / Crescimento e produção de biomassa da palma forrageira segundo ciclo irrigada com esgoto doméstico tratado

This study aimed to evaluate, in the second cycle, the growth and production of 'Orelha-de-elefante Mexicana' prickly pear (Opuntia sp.) under complementary irrigation with treated domestic sewage. The experiment was carried out in the Milagre Settlement, municipality of Apodi-RN, Brazil, from June 2016 to February 2017. Five treatments were evaluated, corresponding to four irrigation frequencies (2.3, 7.0, 14.0 and 21.0 days) to apply an effluent depth of 3.5 mm, and the control, rainfed cultivation (without irrigation). The experimental design was randomized blocks, with four replicates. After preliminary-primary treatment, the domestic sewage showed acceptable chemical and physical characteristics for fertigation under the conditions adopted in the prickly pear cultivation. 234 days after the 1st cut in the plants, the following morphometric characteristics were measured: plant height and length, width, perimeter, thickness and number of primary and secondary cladodes, and biomass accumulation. Complementary irrigation with treated domestic sewage effluent applied at intervals of 2.3, 7.0, 14.0 and 21.0 days allowed satisfactory growth and production of 'Orelha-de-elefante Mexicana' prickly pear; without irrigation, its development was substantially hampered during the dry period. Complementary irrigation with 3.5 mm of domestic sewage effluent applied at intervals of 2.3, 7.0 and 14.0 days led to highest growth and biomass accumulation in 'Orelha-de-elefante Mexicana' prickly pear.

Objetivou-se com esse trabalho avaliar, no segundo ciclo, o crescimento e a produção da palma forrageira orelha-de-elefante (Opuntia sp), conduzida sob irrigação complementar, com esgoto doméstico tratado. O experimento foi realizado no Assentamento Milagre, município de Apodi/RN, no período de junho/2016 a fevereiro/2017. Foram estudados cinco tratamentos, sendo quatro frequências de irrigação (2,3; 7; 14 e 21 dias), para aplicar uma lâmina de 3,5 mm de efluente, e a testemunha, cultivo em sequeiro (sem irrigação). Utilizou-se o delineamento de blocos casualizados com quatro repetições. A água de esgoto doméstico após passar pelo tratamento preliminar-primário apresentou características químicas e biológicas aceitáveis para a fertirrigação nas condições utilizadas no cultivo da palma. Após 234 dias do 1º corte realizado na palma, foram feitas medições das características morfométricas: altura de planta, comprimento, largura, perímetro, espessura e número de cladódios primário e secundário e acúmulo de biomassa. A complementação hídrica realizada por irrigação com intervalos de 2,3; 7,0; 14,0 e 21,0 dias, viabilizou satisfatoriamente o crescimento e a produção da palma forrageira orelha de elefante que, sem irrigação, teve seu desenvolvimento bastante comprometido no período seco. A complementação hídrica com 3,5 mm de água de esgoto doméstico tratado por irrigação, com intervalos de 2,3; 7,0 e 14,0 promovem o maior crescimento e acúmulo de biomassa da palma forrageira orelha de elefante.

Produção de capim elefante utilizando percolado de aterro sanitário / Production of elephant grass using leachate landfill

O uso do percolado de aterro sanitário (PAS) na produção de biomassa para fins energéticos é uma alternativa que minimiza a degradação ambiental. O presente trabalho objetivou analisar o efeito de distintas doses de PAS na produção de capim elefante (Pennisetum purpureum Schum.). Para isso, montou-se o experimento no delineamento em blocos casualizados, com cinco tratamentos (T1 - somente água de abastecimento - AA; T2 - 1mm dia-1 de PAS mais AA; T3 - 2mm dia-1 de PAS mais AA; T4 - 3mm dia-1 de PAS mais AA; e T5 - 4mm dia-1 de PAS mais AA) e cinco repetições, totalizando 25 parcelas experimentais. O capim elefante foi cultivado em ARGISSOLO VERMELHO - AMARELO Eutrófico, durante 132 dias em Mossoró/RN. Ao final do ciclo do capim elefante foram determinadas as características vegetativas altura de planta (AP), massa úmida da planta (MUP) e da folha (MUF) e massa seca das folhas (MSF). Comprovou-se para MUP, MUF e MSF que não houve diferença estatística entre os tratamentos, entretanto, para AP, o tratamento T2 apresentou maior valor (2,86m), diferindo estatisticamente dos tratamentos T4 e T5. Em geral, o tratamento T2 apresentou melhor desempenho com relação às características vegetativas do capim elefante.

The use of landfill leachate (PAS) in the production of biomass for energy is an alternative that minimizes environmental degradation. This study aimed to analyze the effect of different doses of PAS in elephant grass production (Pennisetum purpureum Schum.). For this, the experiment was set up in a randomized block design with five treatments (T1 - only water supply - AA, T2 - 1 mm day-1 of PAS more AA, T3 - 2 mm day-1 of PAS more AA, T4 - 3 mm day-1 of PAS more AA and T5 - 4 mm day -1 of PAS more AA) and five repetitions, totaling 25 experimental plots. The elephant grass was cultivated in ultisol during 132 days in Mossoró/RN. At the end of elephant grass cycle were determined vegetative characteristics plant height (PH), plant fresh weight (MUP), leaf fresh weight (MUF) and leaf dry weight (MSF). It was shown to MUP, MUF and MSF that there was no statistical difference between the treatments, however, to AP, T2 treatment the highest values (2.86 m), differing of the treatments T4 and T5. In general, treatment T2 showed a better performance with respect to elephant grass vegetative characteristics.

Gotejadores aplicando proporções de tempo de irrigação com efluente da suinocultura e água de abastecimento / Drippers applying proportions of irrigation time with swine wastewater and water supply

Este trabalho objetivou analisar os efeitos de proporções de tempo de irrigação com água residuária da suinocultura (ARS) e água de abastecimento (AA) na alteração de indicadores de desempenho hidráulico de sistemas de irrigação com três modelos de gotejadores (G1 - não autocompensante de 2,0 L h-1, G2 - não autocompensante de 1,7 L h-1 e G3 - autocompensante de 3,6 L h-1). O experimento foi realizado junto ao Departamento de Engenharia Agrícola (DEA/UFV) em Viçosa-MG, tendo os seguintes tratamentos: i) 1E3A(1 h de ARS e 3 h de AA); ii) 2E2A (2 h de ARS 2 h de AA); iii) 3E1A (3 h de ARS e 1 h de AA); e iv 4E (4 h de ARS). As características físico-químicas e biológicas da ARS e AA foram determinadas a cada 20 h e 80 h, respectivamente. Os valores do coeficiente de variação de vazão (CVq), coeficiente de uniformidade estatística (Us) e coeficiente de vazão relativa média (DRA) foram obtidos a cada 20 h, durante 160 h de operação do sistema. Após 160 h, gotejadores e linhas laterais foram dissecados para investigação do material ocasionar de obstrução. A obstrução por biofilme foi mais acentuada nas combinações G1 x 2E2A e G1 x 3E1A, enquanto as combinações G2 x 1E3A e G3 x 4E apresentaram os maiores valores de desempenho hidráulico, minimizando a obstrução nas unidades de irrigação com biofilme.

This study aimed to analyze the effects of irrigation time with swine wastewater (ARS) and water supply (AA) on alteration of hydraulic performance indicators in irrigation systems with three models drippers (G1 - non pressure compensating for 2.0 L h-1, G2 ­ non pressure compensating for 1.7 h L-1 and G3 - pressure compensating for 3.6 h L-1). The experiment was conducted at the Agricultural Engineering Department (DEA/UFV) in Viçosa-MG, with the following treatments: i) 1E3A (ARS 1 h and 3 h AA); ii) 2E2A (ARS 2 h and 2 h AA); iii) 3E1A (ARS 3 h and 1 h of AA); and iv 4E (ARS 4 h). The physico-chemical and biological characteristics of ARS and AA were determined every 20 h and 80 h, respectively. The coefficient of variation of discharge (CVq), coefficient of statistical uniformity (Us) and coefficient of relative mean flow (Dra) were obtained every 20 h, during 160 h of operation. After 160 h, drippers and lateral lines were dissected to investigate the material cause of obstruction. The obstruction by biofilm was more pronounced in combinations G1 x 2E2A and G1 x 3E1A, while the combinations G2 x 1E3A and G3 x 4E showed higher hydraulic performance, minimizing the obstruction on irrigation units with biofilm.