The effects of applied N, K and Mg on the distribution of magnesium in the plant

Four samples of soil from a field experiment, with a range of exchangeable magnesium, were used in a pot experiment to study the effects of varying the N- and K-levels on water-soluble, acetone-soluble (chlorophyll) and insoluble (fibre) magnesium in the grass. Irrespective of treatment, water-soluble and total magnesium concentrations in the plant increased as the season progressed. Irrespective of the amount of potassium applied there was a very good correlation between water-soluble and total magnesium in the grass. There was also a good linear relationship at each cut between exchangeable soil magnesium and the concentration of both total and water soluble magnesium in the plant, but not with acetone-soluble or insoluble magnesium. Increasing potassium fertilizer highly significantly reduced total and water-soluble magnesium and increased the fibre magnesium content of the grass. Increasing N increased total and water-soluble magnesium only at the low K level. re]19721212