The paper presents the results of measurements of some chemical properties for 14 drained fen peat-moorsh layers taken from north-east, central and east part of Poland. These areas were drained in order to use as a grassland and most of them in former time were under subirrigation systems. The following basic chemical properties were analysed: organic C, total N, C:N ratio, pH and ash content. In the paper also the relationships between some basic chemical and physical properties were analysed (ash content with bulk density, particle density and porosity). Increasing of ash content caused the decreasing of some chemical properties (organic carbon and total nitrogen content) and increasing some physical properties (bulk density and particle density).
In this paper a model is proposed for water retention prediction with soil structure parameters. It is a correlation model in which the parameters are: bulk density, specific surface area, proportional content of silt and clay as well as proportional content of water-stable aggregates of sizes 1-3, 3-5 and 5-10 mm.
Changes in water retention curves caused by an addition of a soil conditioner (Solacrol) are discussed. The investigations were carried out on the different size aggregates of two types of soils. It was stated that stabilisation of soil aggregates changed the courses of water retention curves. The use of Solacrol generally caused a significant increase of retained water (above 5%) in case of Orthic Luvisol aggregates smaller than 3 mm for pF values below 2 and Haplic Phaeozem aggregates smaller than 0,5 mm for pF values below 1.5.