The Effect of Phosphorus Source on the Movement and Uptake of Band Applied Manganese

Abstract

AbstractPlant uptake of band‐applied Mn from a Selma silt loam soil (pH 7.0) was enhanced by blending MnSO4·H2O with each of four P sources in growth chamber tests. The relative value of ammonium polyphosphate (APP), monoammonium phosphate (MAP), diammonium phosphate (DAP), and monocalcium phosphate (MCP) in increasing Mn uptake by soybeans (Glycine max ‘Hawkeye’) was MAP = APP≫MCP = DAP. There was a highly significant correlation between the plant concentration of Mn and P. Plant uptake of Mn was greatest when the pH of the P source was between 2 and 4. The amount of Mn which was absorbed per increment of P varied with the P source. In this experiment APP = MAP > MCP > DAP.Manganese movement and recovery (measured as exchangeable plus easily reducible) as influenced by P source decreased in the order: APP > MAP > MCP≫DAP. Manganese movement from phosphate mixtures was not detected when the soil pH was greater than 5.8.