Suscetibilidade magnética do solo e estimação da capacidade de suporte à aplicação de vinhaça

Abstract

Resumo -O objetivo deste trabalho foi avaliar a eficiência da suscetibilidade magnética do solo para estimar a capacidade de suporte de áreas à aplicação de vinhaça. Foram coletadas 241 amostras de solo, de uma área de 380 ha, nas quais foram determinados os atributos químicos, os teores de argila e a suscetibilidade magnética do solo. Foram calculadas as doses de vinhaça recomendadas para cada amostra. Os dados foram submetidos à análise estatística descritiva, e foram desenvolvidos modelos de regressão entre a suscetibilidade magnética e os outros atributos avaliados. A análise da dependência espacial dos dados foi feita com uso da geoestatística. Foram construídos mapas de krigagem e variogramas cruzados, para averiguar a correlação espacial entre a suscetibilidade magnética e os atributos estudados. Com base no mapa de recomendação de vinhaça, nas classes de solo e nos mapas de krigagem, foram calculadas as doses médias de vinhaça e as capacidades de suporte médias, ponderadas pela área. A suscetibilidade magnética apresenta correlação espacial linear significativa com as doses de vinhaça recomendadas e com a capacidade de suporte do solo à aplicação desse efluente, e pode ser utilizada como componente da função de pedotransferência, na quantificação indireta da capacidade de suporte.Termos para indexação: geoestatística, mapeamento de solo, pedometria, pedotransferência. Soil magnetic susceptibility for estimating the support capacity to vinasse applicationAbstract -The objective of this work was to evaluate the magnetic susceptibility efficiency for estimating the support capacity of areas for vinasse application. Two hundred forty-one soil samples were collected from a 380-ha area, on which soil chemical properties, clay content, and magnetic susceptibility were determined. Vinasse requirement was calculated for each sample. Data were subjected to descriptive statistical analysis, and regression models were developed between magnetic susceptibility and the other evaluated attributes. The analysis of data spatial dependence was performed using geostatistics. Kriging maps and cross variograms were built in order to investigate the spatial correlation between soil magnetic susceptibility and studied attributes. Based on the map of vinasse requirement, on the soil classes, and on the kriging map, calculations were done for average vinasse dose and average soil support capacity, weighted by the area. Magnetic susceptibility has significant linear spatial correlation with recommended vinasse doses and soil support capacity for the application of this effluent, and it can be used as a pedotransfer function for indirect quantification of soil support capacity.

Chemical soil attributes evaluated by multivariate techniques and geostatistics in the area with agroforestry and sugarcane in Humaitá, AM, Brazil

“…Several studies show correlation or spatial dependence of soil chemical attribute variability (PELUCO et al, 2013;DALCHIAVON et al, 2014;BOTTEGA et al, 2013).…”

Proposal of the Spatial Dependence Evaluation From the Power Semivariogram Model

“…There may be mentioned the Relative Nugget Effect (NE) (Trangmar, Yost, Uehara, 1985;Cambardella et al, 1994) and the Spatial Dependence Degree (SPD) (Biondi, Myers, Avery, 1994), considering, respectively, the following relations between the parameters of the semivariogram: nugget effect (C0) and sill (C0 + C1); contribution (C1) and sill (C0 + C1). These two indexes to evaluate the spatial dependence are used by many studies, for example, Barbieri et al (2013), Costa et al (2013), Kamimura et al (2013), Neves , Peluco et al (2013), Santos, H. et al (2013), , Nascimento et al (2014), Lundgren, Silva, Ferreira (2015), Rocha et al (2015).…”

Magnetic susceptibility for characterizing areas with different potentials for sugarcane production

“…bras., Brasília, v.51, n.9, p.1349-1358, set. 2016 DOI: 10.1590/S0100-204X2016000900034 which can help to make decisions on crop management (Peluco et al, 2013).…”

“…Recently, Siqueira et al (2010a) used it for the quantification of physical, chemical, and mineralogical attributes of soils with low iron content, i.e., less than 4% as Fe 2 O 3 . Magnetic susceptibility has also been used in sugarcane plantations in Brazil to identify areas with different potentials for soil CO 2 emission (Barrios et al, 2012;Leal et al, 2015) and with different capacity to endure vinasse application (Peluco et al, 2013), as well as to quantify adsorbed phosphorus (Peluco et al, 2015) and to map management units (Matias et al, 2015;Siqueira et al, 2015). However, few works focus on identifying the relationship between magnetic susceptibility and plant characteristics .…”