ANALYSIS OF MACRO- AND TRACE ELEMENTS IN HORTICULTURAL SUBSTRATES BY MEANS OF THE CaCl₂/DTPA METHOD

The extraction of horticultural substrates by means of a new method (0,01 M CaCl₂ + 0,002 M DTPA; 25 g substrate per 200 ml of extractant) is suggested. Not only macro- and trace elements (except Ca), but also toxic elements as Cd, Pb and Al can be measured in the extract.

In pot trials a very close relationship between P content of substrate and growth has been found.

In comparison to some other methods the new method shows advantages as far as (a) estimation of P supply, (b) measurement of content of exchangeable cations and (c) measuring many elements in one single extract are concerned.