Factors affecting potassium fixation in Argentine agricultural soils

• Published in: Communications in soil science and plant analysis 2001-10, Vol.32 (17-18), p.2679-2690
• Main Authors: Conti, M. E., de la Horra, A. M., Effron, D., Zourarakis, D.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; B-fertilizer K rate; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; K fixation; Mineral components. Ionic and exchange properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Q/I isotherms; Residuality index; Soil science
• ISSN: 0010-3624; 1532-2416
• DOI: 10.1081/CSS-120000954

Potassium (K) fixation in Argentine soils and its effects on fertilizer K dose effectiveness remains an under-researched topic. The effects of K addition doses and clay type and content on the K fixation/release dynamics of added K in four soils, two Argiudols, an Ultisol and an Andisol were studied. Fixation responded to soil type, but not to K doses. From 5 to 24% of the applied K was fixed by the soils ranking from highest to lowest: Aquic Argiudol, Typic Palehumult, Typic Udivitrand and Typic Argiudol. The trend for K fixation relative to clay content was reversed. The soils fixed between 0.23 and 2.38 (cmol c  kg −1 ) (g clay) − 1 in increasing order: Typic Argiudol, Typic Palehumult, Aquic Argiudol and Typic Udivitrand. Potassium fixation by occlusion in clay pores could account for the high activity of the Andisol. The Q/I isotherms results were consistent with those from the fixation experiment. The residuality index, B, ranged from 0.65 (Aquic Argiudol) to 0.95 (Typic Argiudol), a trend consistent with K fixation by these soils. Exchangeable K measured in the fertilized soils and calculated through the residuality index was highly correlated (r=0.95; p