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De Oliveira E.C.A.,Federal Rural University of Pernambuco | de Castro Gava G.J.,Sao Paulo State Agribusiness Technology Agency APTA | Trivelin P.C.O.,Center for Nuclear Energy in Agriculture | Franco H.C.J.,CTBE - Brazilian Bioethanol Science and Technology Laboratory
Journal of Plant Nutrition and Soil Science | Year: 2013

Adequate measurements of the nitrogen (N) concentration in the aboveground biomass of sugarcane throughout the growth cycle can be obtained using the critical N dilution curve (CNDC) concept, which provides an N-nutrition index (NNI). The aim of this work was to determine the CNDC value for Brazilian sugarcane variety SP81-3250, establish the critical concentration of N, and determine the NNI in the aboveground biomass throughout the cane plant and first ratoon crop cycles. The study was performed in three experimental areas located in São Paulo, Brazil, during the crop cycles of 2005/2006 (18-month cane plant) and 2006/2007 (first ratoon). The plant cane crop was fertilized with treatments of 40, 80, or 120kg N ha-1 and a control treatment without N. After the plant cane harvest, rates of 0, 50, 100, or 150kg N ha-1 were applied to the control plot and the 120kg N ha-1-treatment plot in a split-plot experimental design with four repetitions. Throughout both sugarcane cycles, measurements of aboveground biomass were used to determine the dry-mass (DM) production and N concentration for each treatment. CNDC varied between the growth cycles, with a higher N concentration observed in the initial stages of the first ratoon and a lower N dilution observed throughout the plant cane cycle. The NNI value indicated excessive N storage in the initial stages and limiting concentrations at the end of the growth cycle. CNDC and NNI allow for the identification of the N-nutrition variation rate and the period in which the nutrient concentration limits the production of aboveground biomass. The equations for the critical N (Ncr) level obtained in this study for plant cane (Ncr = 19.0 DM-0.369) and ratoons (Ncr = 20.3 DM-0.469) can potentially be used as N-nutritional diagnostic parameters for sugarcane N nutrition. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Longo C.,Center for Nuclear Energy in Agriculture | Longo C.,Jülich Research Center | Longo C.,University of Bonn | Abdalla A.L.,Center for Nuclear Energy in Agriculture | And 6 more authors.
Czech Journal of Animal Science | Year: 2013

Tanniferous forages may have bacteriostatic and/or bactericidal effect on different rumen microbial populations. We investigated the influence of the tropical tanniferous plants Styzolobium aterrimum (STA), Styzolobium deeringianum (STD), Leucaena leucocephala (LEU), and Mimosa caesalpiniaefolia (MIC) containing 20, 64, 56, and 105 g condensed tannis (CT)/kg dry matter (DM) and Cynodon spp. cv. Tifton 85 (CYN) as control on Fibrobacter succinogenes and methanogenic microbes in rumen liquor from sheep using the in vitro gas production technique (Hohenheim gas test). The relative gene expression of F. succinogenes at t1/2 (time point when 50% of the maximal gas production has been reached) analyzed by quantitative PCR was 0.20- and 0.28- fold lower than the control when LEU and STA was applied and 0.91- and 0.85-fold lower with MIC and STD. Methanogenic population was 0.29- and 0.58- fold reduced with STA and LEU compared to the control, but 5.50- and 1.43- fold higher with MIC and STD. At 24 h, F. succinogenes was reduced for all legumes as well as methanogenic bacteria, except for MIC which increased 4.15-fold. Denaturing gradient gel electrophoresis (DGGE) of the methanogenic community resulted in different band patterns: CYN presented some strong bands, which became weaker in the analyzed treatments. Some bands appeared weaker, especially in MIC and STD, but not in STA and LEU. MIC seemed to increase the total number of weak bands. Overall, the tannin-rich plants negatively affected the F. succinogenes population and caused changes in the structure of the methanogenic community.

Longo C.,Center for Nuclear Energy in Agriculture | Longo C.,University of Bonn | Longo C.,Jülich Research Center | Hummel J.,University of Bonn | And 7 more authors.
Czech Journal of Animal Science | Year: 2012

Leucaena leucocephala (LEU) and three under-utilized tanniferous legumes, Styzolobium aterrimum L. (STA), Styzolobium deeringianum (STD), and Mimosa caesalpiniaefolia Benth (MIC) were chemically characterized and the biological activity of tannins was evaluated using in vitro simulated ruminal fermentation through tannin-binding polyethylene glycol (PEG) and compared with a non-tanniferous tropical grass hay, Cynodon spp. (CYN). The Hohenheim gas test was used and gas production (GP) was recorded at 4, 8, 12, 24, 32, 48, 56, 72, 80, and 96 h incubation with and without PEG. Kinetic parameters were estimated by an exponential model. STA, STD, and LEU contained higher (P < 0.05) crude protein than MIC, which had greater neutral detergent fibre and acid detergent fibre. Total phenols, total tannins, and condensed tannins (CT) were consistently the highest in MIC. Gas production was the lowest from MIC (P < 0.05) and the highest in LEU and STA. MIC + PEG largely reduced (P < 0.05) the lag phase and the fractional rate of fermentation and increased potential GP. Kinetic parameters of STA + PEG and LEU + PEG were not affected. LEU + PEG produced greater gas increment (P < 0.05) than STD + PEG, although both legumes had the same CT. All legumes except MIC were more extensively degraded than CYN. However, fermentation of the legumes was differently affected by the presence and proportions of CT, indigestible fibre or both.

Pessenda L.C.R.,Center for Nuclear Energy in Agriculture | Vidotto E.,Center for Nuclear Energy in Agriculture | De Oliveira P.E.,Universidade São Francisco | Buso A.A.,Center for Nuclear Energy in Agriculture | And 4 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2012

A 190. cm mangrove sediment core from the Ilha do Cardoso State Park, State of São Paulo, southeastern Brazil was analyzed for pollen, diatoms as well as carbon and nitrogen isotopes. The goal was to determine the dynamics of the coastal terrestrial/aquatic ecosystems, vegetation history and climate change in this region of the Brazilian Atlantic rainforest, during the Late Pleistocene and Holocene. The values for total organic carbon-TOC (from ~3 up to 40%), C/N ratios (from ~10 up to 130), and δ 15N (~0 to >8) are associated with well preserved aquatic and terrestrial organic matter and possibly influenced by nitrogen cycling (e.g., denitrification) that caused 15N enrichment between >40,000calyrB.P. and ~23,000calyrB.P. Depleted δ 13C values (~ -28.0‰) are also observed and indicate the predominance of C 3 plants. During this time interval, the pollen analysis reveals the presence of the genera Ilex, Alchornea, Weinmannia, Myrsine, Symplocos, Drimys and Podocarpus on a site currently occupied by mangrove vegetation. These data suggest that in the past prevailed a colder and more humid climate than today, with a low relative sea-level. From ~23,000calyrB.P. to ~2200calyrB.P. a sedimentary hiatus likely occurred, related to an erosive event associated to the post glacial sea-level rise. Since at least ~2200calyrB.P., sediments are marked by relatively low C/N ratios (from 2 to 27), exhibit more enriched δ 13C (from ~-26.0‰ to -24.0‰) and δ 15N (up to ~7) values and are characterized by the presence of marine diatoms. This indicates the return of the marine coastal line to its current position, and consequently the development of mangrove. © 2012 Elsevier B.V.

Cohen M.C.L.,Federal University of Pará | Franca M.C.,Federal University of Pará | de Fatima Rossetti D.,National Institute for Space Research | Pessenda L.C.R.,Center for Nuclear Energy in Agriculture | And 5 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2014

The sedimentary deposits of the deltaic plain of the Doce and Barra Seca rivers, Southeastern Brazil, were studied by facies analysis, pollen records, δ13C, C/N analysis and AMS 14C-dating. Today, this deltaic plain is dominated by beach ridges and sandy terraces occupied by arboreal and herbaceous vegetation. Between ~47,500 and ~29,400calyrB.P., a deltaic system was developed in response mainly to eustatic sea-level fall. Although the studied stratigraphic succession is compatible with the trend of global sea-level fall, the earlier sea-level suggested by the topographic position of these deltaic deposits was above the one expected during the MIS3 stage. A tectonic uplift likely occurred during the late Quaternary and raised these deposits. The post-glacial sea-level rise caused a marine incursion with invasion of embayments and broad valleys, and it favored the evolution of an estuary with wide tidal mud flats occupied by mangroves between ~7400 and ~5100calyrB.P. The high river sand supply and/or the relative sea-level fall in the late Holocene led to seaward and downward translation of the shoreline during normal/forced regression, producing progradational deposits with shrinkage of mangrove stands and expansion of marshes colonized by herbaceous vegetation. Therefore, the stratigraphic architecture and evolution of the Doce River deltaic plain suggest that fluvial sediment supply and relative sea-level fluctuations related to Quaternary global climatic changes and local tectonism exerted major controls on sedimentation through the variation of accommodation space and base-level changes. © 2013 Elsevier B.V. All rights reserved.

Otto R.,University of Sao Paulo | Castro S.A.Q.,University of Sao Paulo | Mariano E.,Center for Nuclear Energy in Agriculture | Castro S.G.Q.,Brazilian Center for Research in Energy and Materials | And 2 more authors.
Bioenergy Research | Year: 2016

Land area devoted to sugarcane (Saccharum spp.) production in Brazil has increased from 2 million to 10 million ha over the past four decades. Studies have shown that, from an environmental perspective, the transformation of nitrogen (N) fertilizers into N2O gases can offset the advantages gained by replacing fossil fuels with biofuels. Our objectives here were to review recent developments in N management for sugarcane-biofuel production and assess estimates of N use efficiency (NUE) and N losses based on future scenarios, as well as for life-cycle assessments of bioenergy production. Approximately 60 % of N-based fertilizer applied to sugarcane fields in Brazil is recovered by plants and soils, whereas N losses to leaching and N2O emissions can average 5.6 and 1.84 % of the total applied N, respectively. Maintenance of trash, rotation with N-fixing legume species, and optimization of byproducts usage have potential for reducing the N requirements of sugarcane cultivation in Brazil. Moreover, the development of sugarcane genotypes with higher NUEs, along with management systems that consider soil capacity of mineralization, is required for improving the NUE of sugarcane. Strategies to maintain N as NH4 + in sugarcane-cropped soils also have the potential to reduce N losses and enhance NUE. The development of second-generation biofuels is important for increasing biofuel production while simultaneously maintaining N rates and improving NUE, and sugarcane systems in Brazil show potential for sustainable biofuel production with low N rates and limited N2O losses. Reducing N rates in sugarcane fields is thus necessary for improving sugarcane-based biofuel production and reducing its environmental impacts. © 2016 Springer Science+Business Media New York

Moretti S.M.L.,Center for Nuclear Energy in Agriculture | Bertoncini E.I.,Sao Paulos Agency for Agribusiness Technology | Abreu-Junior C.H.,Center for Nuclear Energy in Agriculture
Scientia Agricola | Year: 2015

Sewage sludge (SS) has been widely used as organic fertilizer. However, its continuous use can cause imbalances in soil fertility as well as soil-water-plant system contamination. The study aimed to evaluate possible improvements in the chemical and microbiological characteristics of domestic SS, with low heavy metal contents and pathogens, through the composting process. Two composting piles were set up, based on an initial C/N ratio of 30:1, with successive layers of tree pruning waste and SS. The aeration of piles was performed by mechanical turnover when the temperature rose above 65 ºC. The piles were irrigated when the water content was less than 50 %. Composting was conducted for 120 days. Temperature, moisture content, pH, electrical conductivity (EC), carbon and nitrogen contents, and fecal coliforms were monitored during the composting. A reduction of 58 % in the EC of the compost (SSC) compared with SS was observed and the pH reduced from 7.8 to 6.6. There was an increase in the value of cation exchange capacity/carbon content (CEC/C) and carbon content. Total nitrogen remained constant and N-NO3- + N-NH4+ were immobilised in organic forms. The C/N ratio decreased from 25:1 to 12:1. Temperatures above 55 ºC were observed for 20 days. After 60 days of composting, fecal coliforms were reduced from 107 Most Probable Number per gram of total solids (MPN g−1) to 104 MPN g−1. I one pile the 103 MPN g−1 reached after 90 days in one pile; in another, there was recontamination from 105 to 106 MPN g−1. In SSC, helminth eggs were eliminated, making application sustainable for agriculture purposes. © 2015, Scientia Agricola. All rights reserved.

Costa J.C.,State University of Ponta Grossa | Borges J.A.R.,State University of Ponta Grossa | Pires L.F.,State University of Ponta Grossa | Arthur R.C.J.,Center for Nuclear Energy in Agriculture | Bacchi O.O.S.,Center for Nuclear Energy in Agriculture
Annals of Nuclear Energy | Year: 2014

The mass attenuation coefficient (μ) is an important parameter to characterize the penetration and interaction of gamma-rays in the soil. Accurate determinations of μ are important to obtain representative values of soil physical properties by gamma-ray attenuation technique. In this study, the effect of collimator size (2-4 mm diameters) and absorber thickness (2-15 cm) on the experimental μ values of water and soils with different textures were investigated for 59.54 keV (241Am) and 661.1 keV (137Cs) gamma-ray sources. Theoretical results were calculated using the program XCOM. Experimental results were compared with theoretical ones showing a good correlation between methods. It was observed that for the 137Cs the best agreements between theoretical and experimental μ were obtained for sample thickness ≥10 cm while for the 241Am were those obtained for thickness <5 cm for small collimators. © 2013 Published by Elsevier Ltd.

Medhat M.E.,Nuclear Research Center - Negev | Medhat M.E.,CAS Institute of High Energy Physics | Pires L.F.,State University of Ponta Grossa | Arthur R.C.J.,Center for Nuclear Energy in Agriculture
Journal of Radioanalytical and Nuclear Chemistry | Year: 2014

In the present work the total mass attenuation coefficients (μ/ρ) for some soils collected from the Southeast and South of Brazil were measured at 59.5 (241Am) and 661.6 keV (137Cs) photon energies. The experimental values of the soils μ/ρ were compared with XCOM program calculations and GEANT4 Monte Carlo simulations. Total atomic and electronic cross-sections, effective atomic and electron numbers of all soil samples were calculated in a wide energy range (1 keV-100 GeV). The values of these parameters have been found to vary with photon energy and chemical composition of the soil. The variations of these parameters with energy are shown graphically for total photon interactions. The results showed that loamy soils have low photon attenuation parameters than clayey ones for the region of 59.5 keV. © 2014 Akadémiai Kiadó.

Cohen M.C.L.,Federal University of Pará | Alves I.C.C.,Federal University of Pará | Franca M.C.,Federal University of Pará | Pessenda L.C.R.,Center for Nuclear Energy in Agriculture | de Fatima Rossetti D.,National Institute for Space Research
Catena | Year: 2015

An integrated approach focused on sedimentology, geochemistry, palynology, C and N isotopes and radiocarbon dating of a sediment core from an herbaceous plain not flooded by tides of the Amapá littoral, near the Amazon River mouth, allowed identification of two phases with marine and terrestrial influences. Mangroves occurred over tidal mud flats with marine influence between >5610-5470 and 470-310calyr BP. The absence of mangrove vegetation since 470-310calyr was followed by the transition of brackish water organic matter to terrestrial C3 plants. Also, the geochemical data indicate a decrease in sea water influence during this last time interval. Likely, the displacement of mangrove forest to lower surfaces was caused by a relative sea-level fall that may be associated with drier conditions with less rainfall during the second part of the last millennium. As suggested by this work, slight relative sea-level fluctuations caused by regional or global climatic change may affect significantly the current mangrove area. © 2015 Elsevier B.V.

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