Control of the ionic composition of the rhizosphere in the transition to soil‐based hydroponic systems

Abstract

With a synthetic (plastic) mulch cover for protection, it was possible to develop a soil‐based gradient‐hydroponic system to control the ionic composition of the rhizosphere. The basic concept was that soluble nutrients placed on the soil bed surface in conjunction with a constant water table would move by gradient to the root as required by the crop. As an alternative, trickle irrigation was used to supply nutrients as well as water to provide a trickle‐hydroponic system. The ionic composition of a standard hydroponic solution is designed to provide nutrients as required without stress. With soil as a complicating factor, the gradient‐hydroponic system is designed to minimize the soil as a factor and provide nutrients as required without stress. A trickle‐hydroponic system, with some limitations, has the potential to do the same thing. To attain a maximum productivity, the soil‐based hydroponic system must be nutritionally evaluated and managed as a hydroponic rather than a soil culture.

Key words:

• Rhizosphere composition management