Interaction of iron chelate and nitrogen fixation in peanuts grown on calcareous soil

Abstract

The interaction of iron (Fe) nutrition and nitrogen (N₂) fixation was examined in peanuts grown in the field for two growing seasons. The treatments were: a) inoculated with Rhizobium, not fertilized with N, b) uninoculated, fertilized with N, and c) uninoculated not fertilized with N. These treatments were tested with or without Fe chelate application. Inoculated peanuts produced up to 42% higher N yield than the uninoculated, non‐fertilized plants. Moderately chlorotic peanuts fertilized with Fe did not increase significantly their yield but had bigger nodules than peanuts not fertilized with Fe. There were no interactions between Fe and N treatments, indicating that both nutrients were important for growth and for N₂ fixation. Remedy of Fe chlorosis on calcareous soils with FeEDDHA will not reduce N₂ fixation.