Use of ion exchange resins in soil and plant testing for micronutrient availability
Tejowulan, R.S., J.J. Schoenau and J.R. Bettany . 1994. In Soils and Crops Workshop Proc., pp 255-267. Univ. Saskatchewan
Abstract
Much effort has been directed
towards the development of soil and plant tissue tests,
to determine the concentration of available
micronutrients in soil and plant materials, quickly and
accurately (Sims and Johnson, 1991; Jones, 1991; Martens
and Lindsay, 1990). Extracting solutions containing a
chelate or weak acid are commonly used to assess
micronutrient availability in soils and plants.
Realization that such methods often remove larger amounts
of the available nutrient pool than do the plants, has
led to concern about their accuracy as indices of plant
availability. Ion exchange resins may be a more
suitable approach to extracting ions from soils and
plants than conventional extracting solutions. Earlier
research has reported that ion exchange resin in a loose
bead form can successfully extract the fraction of
exchangeable Cu, Zn, and Mn that is taken up by plants
during the growing period. However, the loose bead form
suffers from separation problems and therefore is not
suitable for routine analysis. With the presence of
exchange resin in a membrane form however, extraction
techniques may be potentially easier in routine analysis,
and also more efficient because of the large surface area
available for adsorption and exchange. The objectives of this research
were : 1) To develop a new technique to extract
bioavailable micronutrients from soil and plant tissue
materials using ion exchange membrane, 2) To validate the
developed techniques, and 3) To provide indexes of
critical micronutrient levels in soils and plant tissue
for the particular methods, crops, and micronutrients.
