Chemical composition of corn and sorghum grains cultivated in Oxisol with different application methods and doses of zinc.

In general, tropical soils present low concentrations of zinc (Zn), and the deficiency of Zn is recognized as a world nutritional problem for cereal production and human beings. Therefore, the main goal of this study was to assess the effects of different methods of Zn application on the quality of corn and sorghum grains grown in Oxisol. Two experiments were set up in the experimental area of UNESP (campus of Jaboticabal, Brazil). The following nine treatments were applied:three doses of Zn by banded application (seed furrows), three doses of Zn by incorporation into soil (0-20 cm depth), foliar application, seed application, and control (no Zn applied). The treatments were arranged in randomized blocks with four replicates. The contents of Zn, carbohydrates and proteins were determined for corn and sorghum grains. Regardless of the method, Zn application promoted higher contents of this micronutrient in corn and sorghum grains. The banded application method of Zn in soil promoted greater contents of total carbohydrates, starch and protein in both cultures. The incorporation of Zn into the soil method provided higher contents of soluble carbohydrates in both corn and sorghum grains

Nitrous oxide emissions from soils under sugarcane fields in the Cerrado.

Soil fertilization with mineral nitrogen and organic fertilizers, such as the vinasse ? a liquid waste from bio-ethanol production, is a common practice on the sugarcane produced in Brazil that can lead to increasing emissions of greenhouse gases. Nitrous oxide (N2O) is a greenhouse gas even more harmful than the carbon dioxide (CO2), and has longer residence time in the atmosphere. The present study has been conducted on a sugarcane irrigated experiment established at the EMBRAPA Cerrados research station, in Brazil. We hypothesized that N2O emissions would be higher in the sugarcane fields, especially in the fertilized areas that combined mineral nitrogen (N) and vinasse (V), than in the native vegetation remnants (Cerrado); and that irrigated soils would have the highest fluxes of N2O. First measurements were done after the application of N and vinasse in May 2014 until June 2014 as an intensive campaign, and continuous monitoring have been conducted so far. Preliminary results showed that higher emissions occurred on soils combining N and V, showing fluxes that were twice as higher than the fluxes from other treatments, and 100 times bigger than fluxes from soils with native vegetation (469±158, 62.3±6.9, and 0.8±0.1 for V+N, N and Cerrado areas, respectively). The present study is pioneer in the Cerrado region and data are important to assess the regional variations on the N2O fluxes in Brazil, to reduce the bias on national estimations of N2O emissions, and to find more sustainable solutions for the production of bio-ethanol from sugarcane

Efeito de linhagem citoplasmática em características de produção de ovinos da raça Merino.

Objetivou-se avaliar a importancia dos efeitos de linhagem citoplasmatica sobre as caracteristicas peso corporal (PCORP), peso de velo sujo (PVS) e diametro da fibra da la (DIAM), respectivamente em 707 e 703 femeas e 350 machos da raca Merino com um ano de idade. Linhagens citoplasmaticas (LCT) foram definidas como as primeiras 41 femeas do pedigree registradas no Brasil, na decada de 30. Informacoes de pedigree incluiram 30640 animais e, em media, 10 geracoes. As avaliacoes foram feitas usando-se metolologia da Maxima Verossimillanca Restrita, sob modelo animal. Para cada caracteristica foram feitas analises com tres modelos (modelo com efeito direto; modelo com efeitos direto e de LCT; e modelo com efeitos direto, materno e de LCT). Os modelos matematicos foram comparados, sequencialmente, do mais simples para o mais complexo pelo teste da razao das verossimilhancas. Nao houve diferencas (P>0,05) entre os modelos onde se inclui e aqueles onde se omitiu o efeito de LCT, indicando nao serem importantes os efeitos citoplasmaticos para as caracteristicas estudadas. Para PCORP, os resultados indicaram haver confundimento parcial entre efeito genetico aditivo materno e feito de LCT. A importancia relativa dos componentes devido ao efeito genetico aditivo materno foi maior para a caracteristica PCORP (26,1;26,3 e 37,1%), seguido dos para PVS (19,5 para os tres modelos) e DA (16,3 para os tres modelos).Resumo expandid

Equivalence of three-dimensional spacetimes

A solution to the equivalence problem in three-dimensional gravity is given and a practically useful method to obtain a coordinate invariant description of local geometry is presented. The method is a nontrivial adaptation of Karlhede invariant classification of spacetimes of general relativity. The local geometry is completely determined by the curvature tensor and a finite number of its covariant derivatives in a frame where the components of the metric are constants. The results are presented in the framework of real two-component spinors in three-dimensional spacetimes, where the algebraic classifications of the Ricci and Cotton-York spinors are given and their isotropy groups and canonical forms are determined. As an application we discuss Goedel-type spacetimes in three-dimensional General Relativity. The conditions for local space and time homogeneity are derived and the equivalence of three-dimensional Goedel-type spacetimes is studied and the results are compared with previous works on four-dimensional Goedel-type spacetimes.Comment: 13 pages - content changes and corrected typo