SPATIAL VARIABILITY OF SOYBEAN YIELD THROUGH A REPARAMETERIZED T-STUDENT MODEL

ABSTRACT: The t-Student distribution has been used to the spatial dependence modelling of soybean yield as an alternative to the normal distribution, being used for data with heavier tails or discrepant values. However, a usual Student t-distribution does not allow direct comparisons of geostatistical methods with a normal distribution. The aim of this study was to assess the soybean yield spatial variability through a reparameterized t-Student linear model, comparing the results with those of a Gaussian linear model. For parameter estimation, a complete maximum likelihood (CML) method was used through an expectation-maximization (EM) algorithm. The maps constructed with both reparameterized t-Student and normal distributions are dissimilar and present a kappa index (K) equivalent to 0.64. The reparameterized t-Student distribution is an alternative in studying data with discrepant values, showing the ability to decrease the influence of these points.

Saved in:
Bibliographic Details
Main Authors: Schemmer,Rosangela C., Uribe-Opazo,Miguel A., Galea,Manuel, Assumpção,Rosangela A. B.
Format: Digital revista
Language:English
Published: Associação Brasileira de Engenharia Agrícola 2017
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000400760
Tags: Add Tag
No Tags, Be the first to tag this record!