Field studies on the magnesium, copper and zinc nutrition of maize

Abstract

SUMMARYSoils from 55 maize fields in southern and eastern England were tested for available zinc, copper, magnesium and potassium by routine extraction procedures. A high proportion (64%) of the samples contained less than the recommended 50 mg/kg available magnesium, and 24% were within the deficiency range (< 25 mg/kg) for this element. Fewer sites were deficient in copper (7%) and zinc (5%) and these were mainly sandy soils or loams developed on Clay-with-Flints over Chalk. Zinc deficiency in maize does not appear to be a serious potential problem in Britain even though it occurs frequently in other countries, including parts of France.A field of maize with growth problems of varying severity was studied in detail and the available magnesium concentrations found to correlate most closely with the degree of stunting. Soils with healthy plants differed from those in stunted patches of the crop by having higher extractable magnesium, copper and potassium contents. In general the composition of the maize leaves tended to reflect the supply status of the soil, except in the case of chlorotic plants.The influence of factors affecting the availability of the elements investigated and the significance of marginal deficiencies of magnesium and micronutrients in maize are discussed.