Effect of sample pretreatment on extractable soil potassium1
作者:
V. A. Haby,
J. R. Sims,
E. O. Skogley,
R. E. Lund,
期刊:
Communications in Soil Science and Plant Analysis
(Taylor Available online 1988)
卷期:
Volume 19,
issue 1
页码: 91-106
ISSN:0010-3624
年代: 1988
DOI:10.1080/00103628809367922
出版商: Taylor & Francis Group
关键词: Soil Testing;K release;Soil rehydration;Soil freezing
数据来源: Taylor
摘要:
Effect of soil sample treatment on potassium (K) release characteristics of Northern Great Plains soils was studied. Samples of agricultural soils were extracted with neutral normal ammonium acetate for K after selected pretreatment. Field‐moist sub‐soil samples with approximately 100 mg/kg extractable K release nearly double this amount after they were air on oven‐dried prior to analysis. The percentage increase in extractable K in dried soils decreased as the K level in the field‐moist soils increased. At 420 and 500 mg/kg, the extractable K content of air‐dried and oven‐dried soils, respectively, equaled the extractable K content of field‐moist samples. Above these concentrations, drying decreased extractable K. Oven‐drying (60 C) affected extractable K more severely than did air‐drying the soils. Drying and grinding the 15‐ to 30‐cm depth samples significantly increased exchangeable K compared to field‐moist samples. Rehydration of oven‐dried soils to 40% water did not affect extractable K. However, results indicated that rehydration of dried soils to 40% water, followed by freezing (‐29 C air temperature) for 15 hours, and redrying the samples to a range of 0.5 to 5% water, returned extractable K to the level which existed in the original field‐moist samples.
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