Spatial variability of an Alfisol cultivated with sugarcane

Joedna Silva Cruz, Raimundo Nonato Assis Júnior, Sammy Sidney Rocha Matias, Jesús Hernán Camacho-Tamayo


Soil variability occurs due to natural and anthropogenic factors acting at various spatial and temporal scales. The purpose of this study was to evaluate the spatial variability as well as the relation of some chemical attributes using different statistical techniques. The study was conducted in the municipality of Maracanaú (CE, Brazil) in the commercial area of sugar cane in a typic Hapludalf. Soils were sampled in a 100 x 100 m grid every 10 m and at a depth between 0 and 20 cm for determination of exchangeable acidity, pH (KCl), Ca, Na, K, Mg, P, N, sum of bases, cationic exchange capacity, base saturation and organic matter. Data were subjected to analysis of descriptive statistics, multivariate analysis and geostatistics. Attributes showed low and medium variability, except for pH that did not show spatial dependence. Different statistical tools helped to identify the soil spatial variability and to get a better understanding of relationships among different attributes. Techniques also allowed to better plan and control agricultural production, especially in carrying out site specific management of agricultural inputs.


Geostatistics, principal components, cluster analysis.

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