Resumen

GONZALEZ, Mirta; MORENO, Gisela; CONTI, Marta Elvira  y  GIARDINA, Ernesto. Use of residual index for improving diagnosis of potassium fertilization in Argentine soils. Agric. Téc. [online]. 2004, vol.64, n.1, pp. 95-100. ISSN 0365-2807.  doi: 10.4067/S0365-28072004000100012.

The aim of this work was to improve the diagnosis of potassium fertilization, correcting the value of available potassium (Ki) obtained by the ammonium acetate method (1N pH 7), by means of the Karpinets B residual index. The B residual index is used to determine the amount of added fertilizer which is fixed in high specificity sites and not available in immediate form for plants. On this basis, an assay was conducted in the Argentine agricultural regions of the Pampa and Mesopotamia, in which the amount of K in fertilizers effectively available to plants was determined as Ki. The measured Ki data were compared with estimates based on the B index fitted equation. Correlations between the Ki measured in the assay and those calculated by the equation was r = 0.98 (p < 0.001)), showing that the equation can be used to adjust the dose of K added as fertilizer.

Palabras clave : exchangeable soil potassium; K residual index.