Chemical characterization of the soils from black pepper ( Piper nigrum L.) cultivation using principal component analysis (PCA) and Kohonen self-organizing map (KSOM)

Purpose Chemical characterization of soils is fundamental for assessing their quality and proposing agricultural practices to ensure high productivity and quality of the crops. In this sense, we evaluate the chemical profile of soils from the black pepper cultivation of the Espírito Santo State, Brazil. Also, the chemometrics tools principal component analysis (PCA) and Kohonen self-organizing map (KSOM) were used for data interpretation. Materials and methods In this study, soil samples from ten properties (P1 to P10) of black pepper cultivation were analyzed. Five samples were collected from each property in depths of 0–20 cm, resulting in a total of 50 samples. A total of 17 chemical parameters were evaluated to characterize the samples according to the chemical similarities. Results and discussion A comparison was made between the chemometric tools (PCA and KSOM) used in the interpretation of the data. Both tools showed satisfactory and very similar results. In addition, the results of the chemical characterization soils are fundamental and can help the professionals in the agricultural practices to ensure high productivity and quality black pepper crops. Conclusions Although KSOM and PCA show similar results, KSOM was more advantageous since it can interpret non-linear variables. Already, PCA requires the use of several principal components for the interpretation of the data.