Keywords: peat soils, organic matter, evolution, transformation, fractions, potassium, properties
// Мелиорация. – 2015. – №1(73).– С. 111-121
The article describes how drainage and longterm (50 yeas) agricultural use of peat soils causes transformation in composition, structure and reserve of potassium fractions. In peatbog soils reserve of gross forms of potassium in 040 cm layer is 560 kg/ha, exchangeable peat forms – 100 kg/ha. In agro peat soils of different stages of evolution gross peat form increases in 2.54.9 times, moving fractions and others increase in 510 times or more. In organic mineral soils with organic matter less than 20 % all fractions decrease. The lowest reserves of peat fraction are in mineral postpeat soil (exchangeable, moving, and available forms are 0.50.52 t/ha and watersoluble form is 0.14 t/ha.