Exchange equilibria of potassium in soils, V. Effect of natural organic matter on K-Ca exchange
| dc.contributor.author | Poonia, S.R. | |
| dc.contributor.author | Niederbudde, E.A. | |
| dc.date.accessioned | 2014-06-24T07:02:51Z | |
| dc.date.available | 2014-06-24T07:02:51Z | |
| dc.date.issued | 1990 | |
| dc.description.abstract | Exchange equilibria of K Ca were sliufied iu live soil samples (Anglberg surface, AILS: Angleberg subsurface. AI1SS; Ottenhofen surface. OHS; Ollenhofen surface limid. OHSL.;Buchholen surface, BHS) from the Federal Republic of Germany. These samples had a wide difference in their clay con-tent, clay mineralogy, CEC, K-fixation capacity, organise maller (OM ), specific .surface area, and surface charge density (SCD). Untreated and H.,O.,treated samples were Ca-saturated and equilibrated with KCl + CaCl, solutions at a constant chloride concentration of 0.025 M I 'in the equilibrium solutions. The experimental results were described, using the Giaines and Thomas, and Babcock and Duckart thcrmodynamic approaches, and various selectivity quotients. Out of five, two soil samples showed a decrease in the Gapon (K0) and Vansclow (Kv) selectivity quotients in the lower K-saturation (i.e., 0-15 exchangeable potassium percentage, EPP', in ABS; 0 30EPPin ABBS) zone on oxidation of OM. In the remaining three soil samples. K0, and Kv increased .with H2O2-treatment for the whole exchange isotherms. The (Gaines and Thomas standard free energy forK-Ca exchange (AGO) decreased in all but one (i.e., ABSS) and Babcock and Duckart (AGO ) in all the soil samples on OM oxidation. The values of AGO were less negative than those of Ado' for Incomparable soil samples. The positive or negative effect of OM on K-preference has been ascribed to fettle "resultant" of the two opposing phenomena, viz.. an increase in SCD and "low K-specific adsorp- to organo-mineral colloids (causing an increase in K-preference). | en_US |
| dc.identifier.citation | Geoderma, 47(1990) 233-242 | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/3243 | |
| dc.language.iso | en | en_US |
| dc.title | Exchange equilibria of potassium in soils, V. Effect of natural organic matter on K-Ca exchange | en_US |
| dc.type | Article | en_US |