Effect of soil characteristics on cadmium absorption and plant growth of Theobroma cacao L. seedlings.

Abstract

BACKGROUND\nCadmium uptake by cacao plants can affect plant growth, consumer s health, and commercialisation. To develop mitigation strategies is essential to know what soil characteristics could influence this absorption. To determine the relation of cadmium absorption and soil characteristics of cacao areas, the response at concentrations of 0, 2, 5, 10, and 20\u2009μg\u2009g-1 of cadmium in three soils of these areas and an andisol were evaluated, using 120-day-old seedlings of four cultivars of Theobroma cacao L.\n\n\nRESULTS\nIn this study, several relations were found between chemical and physical soil characteristics and available cadmium like real and bulk densities, and contents of iron, sand, magnesium, potassium, sodium, and copper. Additionally, from moderate to strong correlations between potassium (r2 \xa0=\xa0-0.56), and real density (r2 \xa0=\xa00.42), with foliar cadmium, were evidenced. Moreover, a differential deleterious effect on cacao growth in variables such as biomass was corroborated in cadmium concentrations from 5\u2009μg\u2009g-1 in the soils. There were no found statistical differences between cultivars in cadmium uptake or plant growth. Finally, a multiple linear regression model is proposed to estimate the foliar cadmium content (r2 \xa0=\xa00.878).\n\n\nCONCLUSION\nSome soil characteristics like density and sand, clay, aluminium, potassium, and iron contents should be considered before establishing cacao crops to avoid cadmium accumulation. The correlation between potassium with foliar cadmium indicated that potassium could be significant in cadmium uptake mitigation strategies. The high correlation between available cadmium and foliar cadmium indicates that the quantification methodology developed using EDTA extractant may be a useful diagnostic tool. This article is protected by copyright. All rights reserved.