Observations on the effect of soil pH upon zinc absorption by soils

Abstract
A study has been made of the effect of rapid pH change upon the absorption of zinc by six soils with diverse organic matter contents. At pH values more than one pH unit above the soil pH, organic matter and zinc in soil solution increased considerably. Addition of calcium caused reprecipitation of organic matter and zinc, suggesting that zinc at high pH is primarily absorbed on organic matter where it is selectively retained as an organic complex.