Nitrogen Uptake Characteristics of Corn Roots at Low N Concentration as Influenced by Plant Age1

Publisher Website
Google Scholar
Abstract
Information is needed on the relation between concentration of N in solution, CN, and the rate of N uptake by corn (Zea mays L.) roots in order to evaluate the soil and crop parameters affecting N fertilizer efficiency. Data on net N influx, In, vs. CN were obtained for N levels below 150 μM on corn plants of seven ages ranging from 15 to 58 days (2 weeks after tasseling). In was determined by measuring rate of N depletion from the solution in which corn plants grew. Both NH+4 and NO‐3 forms of N were used. The experiments were conducted in the growth chamber and greenhouse.Maximum influx, In‐max, occurred above 21 μM N concentration. Values of In‐max, varied with plant age and were greatest with 18 to 24‐day‐old plants and decreased exponentially to 58‐day‐old plants. In ceased when the averaged CN value decreased to 4 μM. This minimum N concentration varied little with plant age. Since the range of CN values where In varied was only 4 to 21 μM, the time period when CN is within this range for corn growing in the field is probably short so In will usually be at either In‐max or 0.

This publication has 0 references indexed in Scilit: