FIELD VARIABILITY OF ELEMENT CONCENTRATIONS IN WHEAT AND SOIL

Field variability of element concentrations in crops is important to consider for nutrient application as well as for evaluation of environmental hazards. The paper gives an analysis of spatially sampled wheat plant tissue in the field to determine spatial properties of 20 elements for a partly sludge-applied agricultural soil in northern Tunisia. A comparison is made with the spatial variability of geochemical elements in the soil. A geostatistical analysis shows that both soil and plant metal concentrations have a spatial structure with a range of 10 to 30 m for the sampling scale considered. Compared with the soil, element variability in the plant is almost an order of magnitude larger. Consequently, the study indicates that field variability of element concentrations in plants can only partially be explained by the corresponding soil variability.