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Soil Potassium‐Moisture Relations: II. Profile Distribution of Exchangeable K in Iowa Soils as Influenced by Drying and Rewetting
Author(s) -
Hanway J. J.,
Scott A. D.
Publication year - 1957
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/sssaj1957.03615995002100050011x
Subject(s) - subsoil , soil water , potassium , water content , moisture , chemistry , extraction (chemistry) , soil test , soil horizon , mineralogy , soil science , environmental science , geology , chromatography , geotechnical engineering , organic chemistry
Exchangeable K was determined in “moist,” air‐dry, and oven‐dry samples from profiles of different Iowa soils. All moist subsoil samples contained low amounts of exchangeable K. Drying increased the exchangeable K in all of the samples, but in general, the subsoils released more K on drying than the surface soils. Thus, the profile distribution of exchangeable K depended upon the moisture content of the soil samples at the time of extraction. No relation existed between the amount of K released on drying and the amount of released K that reverted to fixed form when the soils were subsequently stored under moist conditions. There was more reversion of K to fixed form in the Marshall profile samples and in samples from below 3 feet deep in the Carrington, Fayette, and Edina profiles than in samples from the upper 3 feet of these profiles. This indicates that greater reversion occurs in the least weathered material. In some cases reversion occurred in the oven‐dried samples but not in the air‐dried samples.