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Concentration of NH3(aq) Required for Incipient NH3 Toxicity to Seedlings
Author(s) -
Bennett A. C.,
Adams Fred
Publication year - 1970
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1970.03615995003400020024x
Subject(s) - loam , chemistry , sorghum , toxicity , malvaceae , gossypium hirsutum , nutrient , nitrogen , ammonia , horticulture , phytotoxicity , zoology , agronomy , soil water , biology , ecology , organic chemistry
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 in which the upper portion of the root medium was a sandy loam surface soil and the lower portion was either a nutrient solution or a treated soil at various levels of pH and ammoniacal‐N. Symptoms of NH 3 toxicity were evident on sudangrass foliage at NH 3 (aq) concentration in the soil solution in situ of 0.17 mM and greater; there was no evidence of NH 3 toxicity at 0.13 mM and less. Symptoms of NH 3 toxicity on cotton roots were evident in soil solutions in situ at NH 3 (aq) concentrations of 0.24 mM and greater but not at 0.17 mM and less; in nutrient solutions, symptoms were evident at 0.22 mM NH 3 (aq) but not at 0.16 mM . The critical concentration for incipient NH 3 toxicity was concluded to be 0.15 to 0.20 mM NH 3 (aq).