Method for the physical characterization of substrates using centrifugation

• Autores: Avrella, Eduarda Demari; Paim, Luciana Pinto; Emer, Aquélis Armiliato; Vence, Lilia Beatriz; Fior, Claudimar Sidnei
• Año de publicación: 2022
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Scientia Agricola; Vol.79, no.5; e20210078; http://www.esalq.usp.br/
• Materia: SPHAGNUM PEAT; SUBSTRATE ANALYSIS; ANALYSIS METHODS; EXPANDED CLAY; WATER RETENTION CURVE
• Institución: Universidad de Buenos Aires. Facultad de Agronomía

Fil: Avrella, Eduarda Demari. Universidade Federal do Rio Grande do Sul. Faculdade de Agronomia. Depto. de Horticultura e Silvicultura. Porto Alegre, Brasil.
Fil: Paim, Luciana Pinto. Universidade Federal do Rio Grande do Sul. Faculdade de Agronomia. Depto. de Horticultura e Silvicultura. Porto Alegre, Brasil.
Fil: Emer, Aquélis Armiliato. Universidade Federal do Rio Grande do Sul. Faculdade de Agronomia. Depto. de Horticultura e Silvicultura. Porto Alegre, Brasil.
Fil: Vence, Lilia Beatriz. Universidad de Buenos Aires. Facultad de Agronomía. Buenos Aires, Argentina.
Fil: Fior, Claudimar Sidnei. Universidade Federal do Rio Grande do Sul. Faculdade de Agronomia. Depto. de Horticultura e Silvicultura. Porto Alegre, Brasil.
The characterization of substrate properties supports the correct choice of components and directs management decisions in container cultivation. There are several systems of analysis, however, the routine procedures to determine the water retention curve (WRC) are time consuming and inaccurate. This study proposed a reproducible, less timeconsuming, and easy to perform method for physical characterization of substrates. We used Sphagnum peat, coconut powder, carbonized rice husk, expanded vermiculite, and expanded clay in isolation. The WRC was obtained at tensions 0, 10, 50, and 100 hPa using the method of Büchner funnel, the European standard (CEN-EN13041), and by the centrifugation method of samples. In centrifugation, tensions were simulated by combining the angular velocity, sample height, and radius measured from the sample outermost point to the central point of the centrifuge. Three rotations were applied (230; 520 and 730 rpm), testing the centrifugation time for each tension and then the volumetric water content was compared between the methods. The results showed a positive correlation (p minor to 0.001) between the centrifugation and standard methods, considering that the centrifugation time required for moisture stabilization varied according to the material analyzed and the tension applied. However, the time required to obtain a report was reduced by half. Sample centrifugation is a promising method, ensuring that the tensile force actually acts on the entire sample to determine the water retention curve of the substrate also reducing the duration of the analyses.
tbls. grafs.