Studies on the behavior of nutrients in the rhizosphere I: Establishment of a new rhizobox system to study nutrient status in the rhizosphere

Abstract

The extent to which barley roots affect the availability of nutrients in the rhizosphere was investigated. The present experiment describes an attempt to study nutrient behavior in the rhizosphere by the establishment of a new rhizobox system. The rhizobox was divided into 5 soil compartments of 5 mm thickness and separated from each other by nylon cloth with a pore radius of less than 25 μm. Barley seedlings grew well for 2 months and roots freely developed in the central compartment (0–5 mm). The solubility of nutrients was evaluated by using such soil extractants as double acid (H₂SO₄ + HC1), ammonium acetate and ammonium bicarbonate‐DTPA solution. The results indicated that the increase in soil pH in the rhizosphere was associated with an increase in Ca and Mg, while the solubility of heavy metals decreased in the soil compartment closest to root planes. The extent of the influence of the root varied depending on kind of ions, treatments and distance from the root plane.

Key words:

• Rhizosphere
• heavy metals
• solubility
• pH changes
• soil test