Under N and P deficient conditions shoot growth, and under low K and Mn root growth are more affected. Carbohydrate stores are depleted from the roots when subjected to inhibitory conditions (Ericsson, 1995). With increasing compaction the oxidation status of Fe changes (due to reduced oxygen), this may affect the solubility of Fe and hence, its uptake by AM and the plant. At C4 in S1 soil the uptake of Fe by AM reduced compared with control but soil sterilization alleviated the stress