Abstract
Zeoponic plant growth media is defined as cultivation of plants on enriched zeolite substrate which contains some of essential plant growth cations on their exchange sites. In addition to the cation exchange sites, the substrate contains minor amounts of other solid phase minerals supplying essential buffering ions, anions and micronutrients. Various types of zeoponic systems have been developed so far. In these systems zeolite supplies K and NH4, apatite supplies Ca, P, Mg, S, Fe, Mn, Zn, Cu, B, Mo, Cl and other calcium bearing minerals such as calcite and dolomite provide Ca and Mg and there is no need to supply nutrient elements with irrigation water. In fact these systems act as slow release fertilizers providing the required elements which are essential for the plant growth. So far, different kinds of zeoponic systems have been developed and National Aeronautics and Space Administration (NASA) researchers had a key role in developing and modifying of this substrate. The present chapter describes some properties, advantages and problems of zeoponic systems.