Rafael Oliveira Batista

Obstrução e uniformidade de aplicação em sistemas de irrigação por gotejamento aplicando-se efluente da suinocultura

This study aimed to evaluate the effect of different managments of swine wastewater and clean water on clogging of emitters and application uniformity of drip irrigation systems. The experiment was conducted in the experimental area of the Federal University of Vicosa (UFV) and mounted in a split split-plots, having in the plots the managments (1E3A - one hour of application of effluent and three hours of application of clean water, 2E2A - two hours of application of effluent and two hours of application of clean water, 3E1A - three hours of application of effluent and one hour of application of clean water and 4E - four hours of application of effluent), in the subplots the types of drippers (G1, G2 and G3) and in the subsubplots the evaluation times (0, 20, 40, 60, 80, 100, 120, 140 and 160 h) in a completely randomized design with three replications. The results indicated that in the swine wastewater the characteristics suspended solids, total iron and bacterial population represented severe risk of clogging of drippers; and that there was a high reduction of the uniformity of application of effluent when the time of application of wastewater is equal to or greater than the water supply.

Desempenho de gotejadores operando com efluente da castanha de caju sob distintas pressões de serviço

Este trabalho objetivou analisar o efeito de distintas pressoes de servico no coeficiente de variacao da vazao (CVQ) de sistemas de irrigacao por gotejamento, operando com agua residuaria da castanha de caju. O experimento foi montado no esquema de parcelas subsubdivididas, tendo, nas parcelas, as pressoes de servico (70, 140, 210 e 280 kPa), nas subparcelas, os modelos de gotejadores (G1, G2 e G3) e, nas subsubparcelas, os periodos das avaliacoes (0, 20, 40, 60, 80, 100, 120, 140 e 160 horas), no delineamento inteiramente casualizado, com tres repeticoes. O CVQ das unidades de irrigacao, bem como as caracteristicas fisico-quimicas da agua residuaria, foram determinados a cada 20 h, ate completar o tempo de operacao de 160 h. Os resultados indicaram que a agua residuaria da castanha de caju representa risco de obstrucao de gotejadores, em relacao as caracteristicas pH, calcio, magnesio, manganes e solidos suspensos. O entupimento parcial dos gotejadores acarretou aumento do CVQ, nas unidades de irrigacao; e as unidades de irrigacao que funcionaram na pressao de servico P1 (70 kPa) apresentaram maior nivel de entupimento de gotejadores, em relacao as demais, em funcao da menor velocidade de escoamento de efluente no interior dos emissores.

Biomassa microbiana e matéria orgânica em solo de Caatinga, cultivado com melão na Chapada do Apodi, Ceará

O uso continuo, ao longo dos anos, do sistema convencional de preparo do solo pode alterar os atributos microbiologicos do solo, causando a reducao da biomassa e da atividade microbiana. Diante do exposto, o objetivo deste trabalho foi avaliar, sob cultivo do melao (Cucumis melo L.), as alteracoes microbiologicas do solo, assim como as do teor de materia orgânica, nas profundidades de 0 a 0,10, 0,10 a 0,20, 0,20 a 0,30 e 0,30 a 0,40 m, ao longo dos anos sob cultivo do melao, durante tres, cinco e dez anos, em Cambissolo Haplico eutrofico, a fim de compara-los com os do solo da mata natural (Caatinga). As amostras foram coletadas, aleatoriamente, na Fazenda Melao Docura, localizada no municipio de Quixere, Ceara, e encaminhadas para o Laboratorio de Analise de Solos, Agua e Planta da UFERSA, Mossoro, Rio Grande do Norte. Determinaram-se os teores de materia orgânica (MO), o de carbono da biomassa microbiana (CBM) e o quociente microbiano (qMIC). O delineamento experimental foi o inteiramente casualizado (DIC), disposto em esquema fatorial 4 x 4 (Fator I, anos de cultivo; Fator II, causa de variacao na profundidade), com tres repeticoes. Os resultados mostraram que a materia orgânica aumentou a partir dos cinco anos de cultivo do melao. O carbono da biomassa microbiana foi elevado nas camadas superficiais, independentemente do tempo de cultivo, por causa da maior disponibilidade da materia orgânica, agua e nutrientes, e o quociente microbiano diminuiu com o tempo, apresentando menor concentracao no cultivo de dez anos do melao, discriminando as possiveis alteracoes decorrentes do uso agricola do solo.

O EFEITO DA ÁGUA RESIDUÁRIA DA SUINOCULTURA NO DESENVOLVIMENTO E QUALIDADE DE MUDAS DE Eucalyptus urophylla

Este trabalho teve como objetivo avaliar o efeito de diferentes proporcoes de ARS (Agua Residuaria da Suinocultura) e duas idades das mudas de Eucalyptus urophylla na sua qualidade morfologica. O experimento foi instalado na Area Experimental de Hidraulica, Irrigacao e Drenagem do Departamento de Engenharia Agricola da Universidade Federal de Vicosa (UFV), em Vicosa, MG, dentro de casa de vegetacao. O experimento foi composto por 10 tratamentos em um esquema fatorial 5 x 2 (5 proporcoes de ARS complementadas com adubacao nitrogenada de cobertura e 2 idades das mudas), com numero de repeticoes diferentes, o delineamento estatistico utilizado foi o de blocos casualizados. Para acompanhar o crescimento das mudas da especie estudada foram avaliadas, aos 75 e 90 dias apos a semeadura, as seguintes caracteristicas morfologicas: altura da parte aerea (H), diâmetro do coleto (DC), massa seca da parte aerea (MSPA), massa seca da raiz (MSR), massa seca total (MST), relacao da altura da parte aerea/diâmetro do coleto (H/DC), relacao da massa seca da parte aerea/massa seca da raiz (MSPA/MSR) e o indice de qualidade de Dickson (IQD). Os resultados obtidos permitiram concluir que a proporcao correspondente a 50% de ARS e a que resulta em melhores caracteristicas morfologicas das mudas de eucalipto. As mudas apresentaram-se aptas ao plantio no campo somente aos 90 dias apos a semeadura.

Chemical Attributes of an Oxisol Under Different Agricultural Uses in the Brazilian Semiarid Region

Different soil managements evidence soil properties, contributing positively or negatively to its quality. A study was conducted in the city of Martins, Rio Grande do Norte (RN) state, in four cultivated areas: corn intercropped with beans (CICB), cassava monocrop (CAMO), bean monocrop (BEMO) and native forest (NF, considered as the original soil condition). This study aimed to evaluate changes in the chemical properties of an Oxisol in function of different agricultural uses (N, P, K+, Ca2+, Mg2+, Na1+, Al3+, pH, EC, H+Al, BS, V, CEC, t, m, OM and ESP) and the distinction of environments using multivariate analysis. The sampling was performed up to 30 cm deep. Soil pH values were kept close to 5.5, except for the area with corn intercropped with beans, whose values were higher than 7.0. Corn intercropped with beans had the highest concentrations of K+, Na+ and Ca2+ on the soil, with a direct impact on base sum. Different uses modified soil chemical properties. Corn intercropped with beans differs from the other treatments due to the addition of solid waste to the soil. Principal component analyses showed pH and exchangeable bases are the most sensitive indicators of environment separation.

Chemical Characteristics of Irrigated Ultisol with Dairy Effluent Dilutions

The objective of this work was to analyze the changes in the chemical attributes of an Ultisol irrigated with different dairy effluent dilutions. The experiment was set up using a randomized block design with five dilutions of dairy effluent (DE) in public water supply (PWS) (T1 only PWS, T2 10% of DE plus PWS, T3 20% of DE plus PWS, T4 30% of DE plus PWS, and T5 40% of DE plus PWS). Soil samples were collected at five depths to quantify the attributes of pH, organic matter (OM), potassium (K), phosphorus (P) and electrical conductivity of the soil saturation extract (ECss). No significant effects of dairy effluent dilutions were found in altering the pH, OM and K+ values of the Ultisol after 240 days of application. However, there was a significant increase of P in T4, and of ECss mainly in the 0.10 to 0.20 m layer of T5.

Productive and morphogenetic characteristics of sunflower irrigated with domestic treated wastewater on northeast semiarid area.

The present study aimed to evaluate the agronomic performance of the sunflower crop irrigated with treated domestic wastewater and normal water (well-water) in a inceptisol of Apodi, State of Rio Grande do Norte, Brazil. The experiment was conducted in a randomized block experimental design, consisting of five treatments and five replications, using the H-251 sunflower cultivar from Embrapa. The treatments consisted of the application of five proportions of wastewater/well-water (T1 - 100% wastewater; T2 - 75% wastewater and 25% well water, T3 - 50% wastewater and 50% well-water, T4 - 25% wastewater and 75% well-water and T5 - 100% well-water plus chemical fertilizer, control). The variables such as plant height, leaf number, diameter of stem and the head, yield, oil production, thousand-grain weight and head weight were evaluated. The combined use of wastewater and well-water is an alternative for the substitution of mineral fertilization with minimal damage to the productive potential and development of the sunflower crop. In general, the T4 treatment was the most adequate to improve agronomic performance of the sunflower.

Qualidade dos frutos de mamoeiro produzidos com esgoto doméstico tratado

Objetivou-se, com a realizacao deste estudo, avaliar a qualidade fisico-quimica e microbiologicas dos frutos do mamoeiro Tainung 1, produzidos mediante proporcoes de tempo de irrigacao com agua de abastecimento (AA) e esgoto domestico tratado em tanque septico seguido de filtros anaerobios (AE). O delineamento experimental utilizado foi o de blocos casualizados com quatro tratamentos e seis repeticoes. Os tratamentos foram compostos por T1 (100% de AA mais adubacao recomendada), T2 (67% de AA mais 33% AE), T3 (33% AA mais 67% AE) e T4 (100% de AE). A qualidade fisico-quimica e microbiologica dos frutos foi avaliada por meio dos seguintes parâmetros: espessura da polpa (EP), firmeza da polpa (FP), teor de solidos soluveis totais (SS), pH, acidez titulavel (AT), relacao SS/AT e nivel populacional de Salmonella ssp. e coliforme totais. Observou-se que as proporcoes de tempo de irrigacao com AA e AE aplicadas nao proporcionaram alteracoes, significativas, nas caracteristicas fisico-quimicas dos frutos do mamoeiro, indicando que os valores encontrados atendem aos padroes exigidos para a comercializacao e consumo in natura. A qualidade microbiologica dos frutos do mamoeiro produzidos com AE e aceitavel para consumo humano, uma vez que, foi constatada a ausencia de Salmonella ssp. e de coliformes totais.

MODELOS EMPÍRICOS DO DESEMPENHO DE GOTEJADORES APLICANDO ÁGUA RESIDUÁRIA DA CASTANHA DE CAJU

The objective of this work was to develop empirical models for hydraulic performance of drippers operating with cashew nut processing wastewater depending on operating time, operating pressure and effluent quality. The experiment consisted of two factors, types of drippers (D1=1.65 L h, D2=2.00 L h and D3=4.00 L h), and operating pressures (70, 140, 210 and 280 kPa), with three replications. The flow variation coefficient (FVC), distribution uniformity coefficient (DUC) and the physicochemical and biological characteristics of the effluent were evaluated every 20 hours until complete 160 hours of operation. Data were interpreted through simple and multiple linear stepwise regression models. The regression models that fitted to the FVC and DUC as a function of operating time were square root, linear and quadratic, with 17%, 17% and 8%, and 17%, 17% and 0%, respectively. The regression models that fitted to the FVC and DUC as a function of operating pressures were square root, linear and quadratic, with 11%, 22% and 0% and the 0%, 22% and 11%, respectively. Multiple linear regressions showed that the dissolved solids content is the main wastewater characteristic that interfere in the FVC and DUC values of the drip units D1 (1.65 L h-1) and D3 (4.00 L h-1), operating at work pressure of 70 kPa (P1).

DIMENSIONAMENTO HIDRÁULICO E AVALIAÇÃO DE UM SISTEMA DE IRRIGAÇÃO LOCALIZADA DE BAIXO CUSTO

The absence of appropriate technology is one of the biggest obstacles to the competitiveness of the family farmer and a barrier that makes it difficult to survive in rural areas. Therefore, the aim of this work the hydraulic design and performance evaluation of low-cost irrigation system, bubbler installed on Settlement Miracles in Apodi-RN. After the implantation of the system, we evaluated the performance indicators: coefficient of uniformity of Christiansen (CUC), distribution uniformity coefficient (CUD), application efficiency (EA), flow coefficient of variation of (CVQ) and average unit flow (Q). Utilized a completely randomized experimental design, where treatments consisted of three evaluation periods (0, 84 and 168 hours of operation), with five repetitions. The data have been submitted to analysis of variance and when significant we proceeded to the average test. All performance indicators evaluated showed a statistically significant difference in terms of hours of operation. The results indicated that the CUC, CUD and EA decreased; already CVQ and Q showed increasing response with increasing hours of operation. Even reducing with the operating time, all performance indicators evaluated were considered acceptable, except EA after 168 hours of operation. Based on the results of this indicator, it can be concluded that the bubbler irrigation system has been well dimensioned and operated within acceptable performance limits.