Soil Exchangeable Potassium Research Articles

The build-up of available potassium under subterranean clover pastures on a podzolic soil

A group of podzolic soils from the Crookwell district of New South Wales was examined for potassium status by field, pot culture, and laboratory experiments. Close relationships were found between the exchangeable potassium and the potassium content of the plant material and uptake of potassium both in the field and in pot culture. However, the measured decreases in exchangeable potassium in soil during plant growth were insufficient to account for the total uptake, indicating that other sources of soil potassium were also available. It is probable that the pasture plants themselves contribute to the conversion of non-exchangeable potassium to exchangeable forms. The results suggest that the range 0.25–0.30 m-equiv. exchangeable potassium per 100 g may be critical for these soils. Exchangeable potassium built up under the subterranean clover pastures plays an important part in eliminating a potential potassium deficiency. Removal of hay from these pastures would seriously deplete this available potassium reserve.

Soil Potassium‐Moisture Relations: III. Determining the Increase in Exchangeable Soil Potassium on Drying Soils

AbstractA comparison was made of different extractants for determining the increase in exchangeable soil K which occurs on drying the soils. Moist and dry surface and subsoil samples of 10 Iowa soil profiles were used. The amount of K released on drying as determined by the different extractants was in the order:NH4OAc > 0.5N HCl > 0.1N HCl > Morgan's solution when 10 g. of soil was leached with 75 ml. of extractant. The amount of K removed by the different extractants was linearly related and highly correlated irrespective of the moisture status of the soil sample, except in the case of some oven‐dry subsoil samples extracted with Morgan's solution. Apparently, some of the K that had been released to an exchangeable form on drying reverted to a non‐exchangeable form during the extraction of some subsoil samples with Morgan's solution.

RELEASE OF POTASSIUM BY 18 ONTARIO SOILS DURING CONTINUOUS CROPPING IN THE GREENHOUSE

Eighteen Ontario soils were ranked according to their capacity to supply potassium from non-exchangeable forms to eight successive crops of alfalfa. This capacity was found to be closely related to the percentage of clay in the soils. Potassium content of the alfalfa and total uptake of potassium were highly correlated with both exchangeable soil potassium and release of potassium from non-exchangeable forms. Exchangeable potassium levels below 100 lb. per acre gave low yields and potassium content of the crop. Excessively high exchangeable potassium levels resulted in luxury consumption of potassium by the crop or in fixation by the soil. In soils at or near their equilibrium exchangeable potassium levels, i.e., not heavily fertilized, there was a close relationship between potassium-supplying power and the exchangeable potassium content measured either before cropping commenced or at the end of the cropping period.

Correlation of Plant Tissue Tests of Corn, Deficiency Symptoms, and Soil Analyses on the Jordan Fertility Plots

AbstractAlthough soil tests, tissue tests, and visual deficiency symptoms have been used rather extensively by many agronomists for the diagnosis of nutrient deficiencies existing in soils and plants, no comprehensive comparison of the interrelationship of those methods of diagnosis is available. Therefore, it was the purpose of this investigation to determine the correlation and relationship of these diagnostic methods to each other for nitrogen, phosphorus, potassium, and magnesium with corn as a test crop. The Jordan fertility plots served admirably as a source of material for such an investigation since they were established in 1881 and have attained stable fertility levels, depending upon the fertilizer treatment of each plot. Two corn hybrids (Ohio K‐24 and Ohio M‐15) were grown on each of the 36 plots on tier 1 in 1948 and again on tier 2 in 1949.The soils were analyzed for available nutrients according to standard accepted methods. Potassium and nitrogen tissue tests were made according to the descriptions of Richer2 and Kohnke3, respectively. The tissue test for phosphorus, as described by Kohnke3, was modified and a tissue test for magnesium was developed. Visual deficiency symptoms for nitrogen, phosphorus, potassium, and magnesium were evaluated on each plot for each of the two corn hybrids. The deficiency symptoms described by previous workers were found to be a reliable guide for distinguishing the plant nutrient deficiencies of nitrogen, phosphorus, potassium, and magnesium.When soil tests, tissue tests, and deficiency symptoms were compared on tiers 1 (unlimed) and 2 (limed) of the Jordan fertility plots with two corn hybrids (Ohio K‐24 and Ohio M‐15), the following conclusions appeared justified.Nitrogen. — An excellent correlation at the 0.1% level of significance was found between tissue tests and visual deficiency symptoms on tiers 1 and 2; however, no correlation was found between the tissue tests and potential nitrification of the soil or visual deficiency symptoms and potential nitrification of the soil.Phosphorus. — Highly significant correlations were found in all instances, namely, between (1) soil tests and tissue tests, (2) soil tests and deficiency symptoms, and (3) tissue tests and deficiency symptoms.Potassium. — All correlation coefficients were significant at the 0.1% level between exchangeable soil potassium and tissue tests, exchangeable soil potassium and deficiency symptoms, and tissue tests and deficiency symptoms.Magnesium. — The correlation coefficients between exchangeable magnesium and tissue tests on the limed tier were not significant at the 5% level but were significant on the acid tier. Significance at either the 1% or the 0.1% level was found between exchangeable soil magnesium versus deficiency symptoms and tissue tests versus deficiency symptoms.Good correlations were obtained in most instances between soil tests, tissue tests, and deficiency symptoms, but no one test is always conclusive.

Report on Exchangeable Potassium in Soils

Report on Exchangeable Potassium in Soils

Report on Exchangeable Potassium in Soils

Report on Exchangeable Potassium in Soils

Preliminary Report Upon the Collabo-Rative Work on the Exchangeable Potassium in Soils

Preliminary Report Upon the Collabo-Rative Work on the Exchangeable Potassium in Soils

The Determination of Exchangeable Potassium in Soils Using Hexanitrodiphenylamine

The Determination of Exchangeable Potassium in Soils Using Hexanitrodiphenylamine

The Use of Nitroso‐R‐Salt in the Determination of Exchangeable Potassium in Soils

Soil Science Society of America JournalVolume 9, Issue C p. 56-60 Article The Use of Nitroso-R-Salt in the Determination of Exchangeable Potassium in Soils† J. Fielding Reed, J. Fielding ReedSearch for more papers by this authorA. Mehlich, A. MehlichSearch for more papers by this authorJ. R. Piland, J. R. Piland Associate Agronomists, and Associate Soil Chemist, respectively.Search for more papers by this author J. Fielding Reed, J. Fielding ReedSearch for more papers by this authorA. Mehlich, A. MehlichSearch for more papers by this authorJ. R. Piland, J. R. Piland Associate Agronomists, and Associate Soil Chemist, respectively.Search for more papers by this author First published: 01 January 1945 https://doi.org/10.2136/sssaj1945.036159950009000C0008xCitations: 1 ‡ Contribution from the Department of Agronomy, North Carolina Agricultural Experiment Station, Raleigh, N. C. Published with the approval of the Director as paper No. 195 of the Journal series. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume9, IssueC1945Pages 56-60 RelatedInformation

The Determination of Small Amounts of Exchangeable Potassium in Soils, Employing the Sodium Cobaltinitrite Procedure1

The Determination of Small Amounts of Exchangeable Potassium in Soils, Employing the Sodium Cobaltinitrite Procedure¹

The Level of Exchangeable Potassium in Soils under Burley Tobacco in the Central Bluegrass Region and Its Relation to the Growth of the Crop

The Level of Exchangeable Potassium in Soils under Burley Tobacco in the Central Bluegrass Region and Its Relation to the Growth of the Crop