When I = 0.1 and 0.7 mol/l, Zn II -PDMA complexes formation shifts slightly to higher pH values, reaching quantitative complexation at pH 7 and 7.5 respectively. Increasing ionic strength therefore affects the stability of [Zn(PDMA)] -shifting the pH range where the PDMA is effective for the complexation of Zn II . In the range above pH of 7.5, typical for Zn deficient soils, Zn II is quantitatively complexed by PDMA at all the tested ionic strength conditions, highlighting the potential for successful application of PDMA in alkaline soils even in extreme ionic strength conditions.