Parameters of Potassium Regime for Some Soils in Bulgaria

Abstract

Grouping of soils into three groups of physical clay content, sorption capacity, sorption equilibrium concentration and equilibrium concentration of K fixation makes sense to differentiate the recommendations for Potassium fertilization within a soil Agrochemical group. Equilibrium concentration of Potassium in the soil solution is an important parameter for assessing the availability of this element for plant nutrition. Its determination, however, is laborious. In the model for Potassium fertilization the content of available Potassium is included as a major value. Determination of exchangeable Potassium by conventional methods is much easier and its value can serve as a criterion for this accessibility.
The aim of the study is to replace the values of the equilibrium concentration of Potassium with those of exchangeable Potassium, such as is found relationship between them. In already made soil agrochemical grouping were defined its boundary values.
The results show that this grouping of soils can be used for assessment of soil supply, and to establish and maintain optimal levels of Potassium, as well as to correct fertilization rates.