INTERVENTION OF THE EDAPHIC PROPERTIES IN THE AVAILABILITY OF MICROELEMENTS IN AGRICULTURAL SOILS

Abstract

The effect of some edaphic factors such as pH, soil organic matter (SOM), synergistic and antagonistic effects can sometimes limit the availability of microelements in agricultural areas. The objective of work was defining the chemical properties that affect the availability of microelements in Brown soils and Vertisols of the Eastern Region of Cuba. In soil samples, were determined the pseudo-total and available Mn, Fe, Co, Ni, Cu and Zn contents by Atomic Absorption Spectrophotometry (EAA). The pH_H2O, pH_KCl, soil organic matter (SOM), exchangeable bases. (Ca^2+, Mg²⁺, Na⁺, K⁺) and base change capacity (CCB) were carried out according to the Soil Laboratory Procedures Manual. The relationships between variables were explained by multivariate methods. The results showed low correlation coefficients between microelements with pH, ​​SOM, Ca^2+, Mg²⁺, Na⁺, K⁺ and CCB in Brown soils. In the Vertisoils, only the correlations between pseudo-total Co, Fe and Zn with Ca²⁺, K⁺ and the CCB were positive and significant. The regression equations of the dependent variables Mn, Ni and Zn in Brown soils, as well as Fe and Zn in Vertisoils presented low coefficients of determination. A limited ability to predict pH, SOM and CCB with the available microelements was observed from the correlation coefficients. The availability of microelements is fundamentally explained by the relationships with the pseudo-total and available forms.