Entity

Time filter

Source Type


Nobre R.G.,Federal University of Campina Grande | Soares L.A.A.,Federal University of Campina Grande | Gheyi H.R.,Campus Universitario Of Cruz Das Almas | de Lima G.S.,Federal University of Campina Grande | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013

The aim of this study was to evaluate the effects of irrigation with water of different salinities and doses of nitrogen fertilization on accumulation of NPK and sodium in the aerial parts of the castor bean, the experiment was conducted in lysimeters. A randomized block design in 5 × 5 factorial arrangement with three replications was used, and the effects of electrical conductivity of water (ECw) varying from 0.4 to 4.4 dS m-1 associated with nitrogen dose (50 to 150% of recommended dose) were studied. The NPK and sodium contents in the aerial parts of to plant in the leaves in comparison to stems and evaluation times 120 days after sowing (DAS) > 46 DAS. In leaves the content at 46 DAS varied according to following sequence K > Na > N > P and at 120 DAS K > N > Na > P while in the stem in both study periods it accumulated in the order Na > K > P ≥ N under water salinity and K > Na > P ≥ N depending on nitrogen fertilization. At 46 DAS, the increasing levels of ECw caused an increase in the Nleaf and Kleaf and nitrogen dose inhibited Naleaf content. At 120 DAS the highest content of Nleaf was obtained in treatment ECw 4.4 dS m-1 and in dose of 150% N while the contents of Kleaf and Kstem were obtained in the dose of 150% N. The P content was not affected by any of the studied factors. Source


de Oliveira P.C.P.,Portal Brazil | Gloaguen T.V.,CETEC | Goncalves R.A.B.,CETEC | Santos D.L.,Campus Universitario Of Cruz Das Almas
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013

The objective of this study was to evaluate the yield of pumpkin (Cucurbita maxima Duch. Coroa IAC) irrigated with treated domestic wastewater. The study was conducted in a completely randomized design with five treatments and four replications. The treatments were: T1- irrigation depth of 150% of crop water demand; T2- irrigation depth of 150% of crop water demand with application of CaSO4in soil; T3- irrigation depth of 100% of crop water demand; T4- irrigation depth of 100% of crop water demand with application of CaSO4in soil and T5- control (without irrigation). The parameters evaluated were: crop yield, weight andnumber offruits, their physico-chemical characteristics and potential contamination by pathogens in water. Significant differences in productivity, yield and number of fruits were identified between the control and all other treatments. The physico-chemical characteristics were similar in all treatments. Thermo tolerant coliforms were detected only on the surface of the fruit, but at levels below theminimum standards established by the sanitary legislation. Source


Silva R.R.,DEBI DTRA UESB. Rua Jose A. Ribas Filho | Prado I.N.,5790 Jd Universitario | Carvalho G.G.P.,Federal University of Bahia | Silva F.F.,DEBI DTRA UESB. Rua Jose A. Ribas Filho | And 6 more authors.
Archivos de Zootecnia | Year: 2010

The objective of this work was to study the effects of different supplementation levels on forage intake, animal performance and nutrients digestibility in Nellore steers finished in Bahia Southwest pastures. The experiment was done in an area of 52.0 ha, divided into eight sectors of approximately 6.5 ha each, with a watering point at center of field. There were studied four levels of supplementation according to the body weight which were T00= mineral, T03= 0.3%, T06= 0.6% and T09= 0.9% of the animal live weight. During the supplementation phase it was a decreasing effect on pasture and in neutral detergent fiber intake. Also it was a linear effect, with increasing the supplementation levels, on intake of crude protein, ether extract, non fibrous carbohydrates, total nutrients digestibility, digestibility energy and metabolizable energy. During the rainy season none of variables was affected. The animal performance presented a linear effect during supplementation and remained unchanged in rainy season. The feed conversion and feed efficiency were positively affected by supplementation levels. There was an increasing linear effect on digestibility coefficients of dry matter, crude protein and non fibrous carbohydrates. The digestibility of neutral detergent fiber presented a quadratic effect while the ether extract was not affected. During the rainy season, none of the variables was affected. Source


Fadigas F.S.,Campus Universitario Of Cruz Das Almas | Sobrinho N.M.B.A.,Federal Rural University of Rio de Janeiro | dos Anjos L.H.C.,Federal Rural University of Rio de Janeiro | Mazur N.,Federal Rural University of Rio de Janeiro
Scientia Agricola | Year: 2010

Soils formed from the Barreiras Group sediments, located mainly along the coast of Brazil Northern and Northeastern regions, generally present low concentrations of iron oxides and total organic carbon, high quantities of quartz in the sand fraction, and kaolinitic clay mineralogy. The objective of the present study was to quantify the pseudo total concentrations of Cd, Co, Cu, Cr, Mn, Ni, Zn and Fe in Xhantic Udox and Xhantic Udult soils derived from these sediments. The reference sites were covered by native vegetation and located in the States of Pará and Amapá, Brazil. Multiple linear regression analysis was applied to determine correlations between soil parameters and the levels of these metals. The best correlation was obtained between Fe, Mn, clay, and silt contents, and Cd, Co, Cu, Zn, Cr, Ni. A correlation between pH and these metal levels was not found. Clay and sand contents showed a negative inverse correlation with the metal levels,of same magnitude but with a different sign; this was the reason for excluding one of the parameters in the regression model. In general, the contents of the elements were lower than those found in soils formed from other parent materials. The Mn content was included in the model of multiple linear regression for Cd and Co, due to its association with these last metals. Silt level showed to have a significant influence in the equations for Cr and Co, which is attributed to the presence of clay minerals and Fe and Mn oxides in ferruginous and clay aggregates of silt size. The equations obtained in this paper, are useful to predict, in general terms, the amounts of those heavy metals in an unknown soil sample, if the soil material were not contaminated or affected by land usage. Thus, they may be applied to evaluate soil contamination by the studied heavy metals. Source


Primo D.C.,UFRB | de Fadigas F.S.,Campus Universitario Of Cruz Das Almas | Carvalho J.C.R.,Campus Universitario Of Cruz Das Almas | Schmidt C.D.S.,UFRB | Borges Filho A.C.S.,UFRB
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2010

The use of agroindustrial waste to produce organic compost can result in greater sustainability for agricultural systems. This study aimed to analyze the final quality of the organic compost, according to their nutrients and the presence of active toxic substances. The combinations of ground tobacco stem, bovine manure and rumen (TF+EB+RB), tobacco stem, cattle manure and Microsept Dust (TF+EB+MP) and tobacco stem and cattle manure (TF+EB) were evaluated. Mean samples of each compost were analyzed to determine the concentration of micro and macro nutrients at 60 and 120 days and to verify the nicotine concentration and the presence or absence of pesticide residues in the raw material (TF) and in the composts obtained at 120 days. The data obtained showed high concentrations of potassium (K), nitrogen (N), chloride (Cl) and iron (Fe) in the final compost compared to the other micro and macro nutrients. Neither pesticides in the raw material (TF), nor presence of nicotine in the mean samples obtained within 120 days was detected, demonstrating the absence of environmental impact risks in the agricultural use of these composts. At the end of the composting process, the mixture TF+EB was the one which resulted in an organic compost with the highest concentration in micro and macro nutrients. Source

Discover hidden collaborations