Nitrogen responses of tall fescue and ryegrass survivor populations from a rate-of-nitrogen experiment

摘要

Survivor populations of ryegrass and tall fescue from an experiment in which nitrogen was applied at rates of 0 to 1344 kg/ha/year were tested for nitrogen response in the range from 0 to 4352 kg N/ha in a single application. Applications above 544 kg N were supra-optimal and were totally toxic at 4352 kg N. There were no indications of adaptation of the different survivor populations to either sub-optimal or supra-optimal levels of nitrogen.