Soil and Plant Testing for Iron: An Appraisal

Abstract

Iron (Fe) deficiency chlorosis in crops is common in highpH calcareous soils. Soil and plant testing is routinely used for diagnosing iron (Fe) deficiency chlorosis in crops, with mixed results. This article presents an overview of the factors that influence soil and plant tissue testing results. It is clear that soil tests for Fe are dominantly influenced by soil pH, bicarbonate, and moisture regime rather soil test result per se. This is because the solubility of Fe is more regulated by soil pH and moisture regime. Plant tissue testing for Fe can complement the results of soil testing for Fe. But at times, especially in calcareous soils, total Fe in plant tissue is not related to Fe deficiency, but metabolically active Fe is better at diagnosing the occurrence of the disorder. A combined use of soil and plant tissue testing seems more helpful in diagnosing Fe deficiency chlorosis disorder in crops.