Genetic diversity of Lusitano horse in Brazil using pedigree information

This study aimed to evaluate population parameters and to describe the genetic diversity of the Lusitano breed in Brazil using pedigree data. Two populations were evaluated: total population (TP) containing 18,922 animals, and reference population (RP) composed of a part of TP containing 8,329 animals, representing the last generation. The generation interval (10.1 ± 5.1 years) was in the range for horse populations. Pedigree completeness in RP shows almost 100% filling in the three most recent generations, indicating improvement in the pedigree data and accuracy of the results, and the inbreeding coefficient (4.46%) and average relatedness (5.97%) for RP, indicating control on the part of breeders. The effective population size was 89 (TP) and 90 (RP). The effective number of founders (fe) were 33 and 29, effective number of ancestors (fa) were 30 and 26, and effective number of founder genomes (fg) were 19 and 15 for TP and RP, respectively, indicating a reduction of genetic variability in the last generations. The total number of ancestors that explains 100% of the genetic diversity in the Lusitano breed in Brazil was 427 (TP) and 341 (RP). The reproductive parameters, probabilities of gene origin showing loss of variability in the last generations, and the genetic contributions of ancestors suggest the need to monitor genetic diversity over time in breeding programs to allow control of the next generations and to increase their variability.info:eu-repo/semantics/publishedVersio

Frações de fósforo e carbono orgânico em Latossolos de Cerrado sob diferentes usos.

Fertbio 2012

Erodibilidade do solo nos tabuleiros costeiros.

Para determinar perdas de solo por erosão hídrica, em diferentes situações, são utilizados modelos de predição de erosão, como a Equação Universal de Perdas de Solo (EUPS). A aplicação destes modelos, no planejamento agrícola e ambiental, depende da determinação dos fatores da EUPS, dentre estes a erodibilidade (fator K). Este estudo teve como objetivo determinar a erodibilidade, para as principais classes de solos da região dos Tabuleiros Costeiros, em Aracruz (ES). O experimento foi instalado nos seguintes solos: Argissolo Amarelo textura média/argilosa (PA1), Plintossolo Háplico (FX) e Argissolo Amarelo moderadamente rochoso (PA2). Para o cálculo da erodibilidade, foram utilizados dados de erosividade e de perdas de solo de novembro de 1997 a maio de 2004. As coletas de perdas de solo foram realizadas para cada evento de chuva considerada erosiva. Os valores de erodibilidade foram 0,007 Mg h MJ-1 mm-1; 0,017 Mg h MJ-1 mm-1; e 0,0004 Mg h MJ-1 mm-1, para PA1, FX e PA2, respectivamente

Análise exploratória dos atributos químicos em solos do cerrado sob diferentes manejo e uso.

FertBio 2014

Aggregate stability in soils cultivated with eucalyptus.

The objective of this work was to evaluate the aggregate stability of tropical soils under eucalyptus plantation and native vegetation, and assess the relationships between aggregate stability and some soil chemical and physical properties. Argisols, Cambisol, Latosols and Plinthosol within three eucalyptus-cultivated regions, in the states of Espírito Santo, Rio Grande do Sul and Minas Gerais, Brazil, were studied. For each region, soils under native vegetation were compared to those under minimum tillage with eucalyptus cultivation. The aggregate stability was measured using the high‑energy moisture characteristic (HEMC) technique, i.e., the moisture release curve at very low suctions. This method compares the resistance of aggregates to slaking on a relative scale from zero to one. Thus, the aggregate stability from different soils and management practices can be directly compared. The aggregate stability ratio was greater than 50% for all soils, which shows that the aggregate stability index is high, both in eucalyptus and native vegetation areas. This suggests that soil management adopted for eucalyptus cultivation does not substantially modify this property. In these soils, the aggregate stability ratio does not show a good relationship with clay or soil organic matter contents. However, soil organic matter shows a positive relationship with clay content and cation exchange capacity