Concentration of NH3(aq) Required for Incipient NH3 Toxicity to Seedlings

Short term experiments with sudangrass ( Sorghum sudanensis L.) and cotton ( Gossypium hirsutum L.) were conducted in a growth chamber to determine incipient toxic levels of NH 3 (aq). Sudangrass seedlings were grown for 14 days in potted Lucedale sandy loam surface soil treated with different rates of N from NH 4 OH, (NH 4 ) 2 SO 4 , and (NH 4 ) 2 HPO 4 . Root growth of cotton seedlings was measured over a 3‐day period in split‐root experiments...