This column study indicates that, when plant amendments are added to soil, Mn and Fe are released at moisture contents below field capacity. Soluble Mn and Fe were released from the soil columns in the order: alfalfa > wheat straw > soil alone. Release was greater at 0.3-bar than at 0.5-bar moisture tension, and the effect was more noticeable for Mn than for Fe. When the easily reducible Mn in the soil was compared with total Mn elution at 0.3 bar, 6.6 and 16.1 times more total Mn than the amount of easily reducible Mn in the soil was eluted from the 2 and 5 percent straw treatments, respectively. The results suggest a potential for soluble Mn accumulations where large amounts of plant residues are incorporated into a normally well-drained soil.