CORRECTION OF ELEMENTAL ANALYSIS OF SOIL-GROWN WHEAT ROOTS CONTAMINATED WITH SOIL

This study addresses the need to determine accurately mineral element concentrations in roots grown in soil so that valid measurements of element uptake and translocation can be made. Wheat (Triticum aestivum L., cv 'Nugains') was planted in seven soils. Two seeds were planted in each soil and two seeds were planted in a Versapor bag that had been buried in the soil in the same 1.3-L ceramic pot. The bag separated the roots from soil. The plants were harvested four weeks after planting. Tops and roots were analyzed separately for 12 elements. Estimates were made for the contribution of each element from soil particles contained in the sampled portion, by using the titanium (Ti) concentration in root sample as a measure of contamination by soil. Concentration corrections ranged from an increase of 14% for Na to a decrease of 131% for Al. Corrected estimates of Al and Fe concentrations in the sample portion were usually unreasonably high or low. In most cases, corrected concentration estimates appeared to be reasonable for most elements. Roots grown within Versapor bags do not appear to be particularly good models of roots growing freely in soil, with respect to root tissue element concentration.