Dissertations and Theses

PEDOMETRIC CHARACTERIZATION OF FERTILITY AND COLOR ULTISOL COHESIVE EAST MARANHENSE

Author: José Maria do Amaral Resende

Keywords: Geostatistics, diffuse reflectance spectroscopy, savannah, landform

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Summary

The cultivation of soils with greater potential for response to land is essential for the establishment of a sustainable agricultural technology. This study aimed to characterize, by pedometrics techniques, color, granulometry and fertility of Ultisols cohesive Eastern Maranhense, and specific objects characterize the spatial variability of soil attributes and color in agricultural areas and native vegetation in town of Brejo, located in the eastern region of Maranhao State, Brasil. Using the constituents of soil color obtained by difuse reflectance spectroscopy in the visible range, as an indicator of specific compartments of the management of soil fertility. For the experiment, we selected three compartments represented by an area cultivated with soybeans and vegetation cover remaining three features of cerrado, called Savana, Typical Cerrado and Cerrado Field. The compartments coverage Savana and Savannah Typical are located in concave landform, and that covered by Campo Cerrado in convex landform. The variability patterns were different, and the environment with greater variability is related to the occurrence of local vegetation in Campo Cerrado in convex landform, suggesting that this is the environment less able to support the management of soybean. 0.5 g of each sample, milled and air dried were measured reflectance values in the range 380-780 nm, from which was determined the values of hue, value and chroma. From these color components, we calculated the redness index for each sample. These values were correlated with remaining phosphorus, cation exchange capacity, percent base saturation and clay content of the samples. The results showed that the constituents of the color thus obtained can be used in the prediction of the parameters of fertility, clay content, the landform and natural vegetation soils.