B. Witkowska-Walczak

Impact of diverse tillage on soil moisture dynamics

Impact of diverse tillage on soil moisture dynamics The influences of traditional and reduced tillage on the water content dynamics of two soils were investigated in a long-term field experiment under nearly the same meteorological conditions for a winter wheat monoculture during three years. In addition to the moisture changes, the basic physicochemical properties, water retention, differential porosity and hydraulic conductivity of the investigated soils were measured. The results have shown the dependence between moisture and the tillage system applied for both types of soil. The soil water content was higher under reduced tillage in comparison to traditional management.

Index of soil aggregates stability as linear function value of transition matrix elements

The paper presents a new index which is an innovative tool for the analysis of soil aggregates stability. The soil aggregates stability index (ASI) is based on a linear function value of transition matrix elements with coefficients being properly chosen weights. Each element of the transition matrix is a frequency (empirical probability) of aggregates transition from one class of size to another or within the same class. The proposed weights give an ASI value range from 1 to 32 and are thus formulated: a higher ASI value corresponds to a higher aggregates stability. The usefulness of the proposed index is illustrated in the case three soils (Haplic Phaeozem, Mollic Gleysol and Orthic Rendzina) for which aggregate water stability was determined by three different methods.

Pedotransfer studies in Poland

Publisher Summary This chapter presents the investigations of the impact of soil physical and chemical parameters on the water retention curve and water conductivity curve that were initiated in Poland. This research aimed at finding relations between the contents of granulometric fractions and the water contents at various values of the soil water potential. Soil organic matter affects water retention because it can retain water by itself and it strongly affects soil microstructure. It was difficult to establish direct relationships between the organic matter content and the water content at a given soil water potential. However, organic matter content is frequently taken into account as a complementary parameter in soil hydraulic property estimations. The chapter performs investigations that aim at estimating the soil hydraulic conductivity of undisturbed structure. The impact of soil physical parameters on the unsaturated hydraulic conductivity at selected soil water potential values is also investigated in the chapter.

Water conductivity of arctic zone soils (Spitsbergen)

Abstract The water conductivity of arctic zone soils derived in different micro-relief forms was determined. The greatest water conductivity at the 0-5 cm depth for the higher values of water potentials (> -7 kJ m-3) was shown by tundra polygons (Brunic-Turbic Cryosol, Arenic) - 904-0.09 cm day-1, whereas the lowest were exhibited by Turbic Cryosols - 95-0.05 cm day-1. Between -16 and -100 kJ m-3, the water conductivity for tundra polygons rapidly decreased to 0.0001 cm day-1, whereas their decrease for the other forms was much lower and in consequence the values were 0.007, 0.04, and 0.01 cm day-1 for the mud boils (Turbic Cryosol (Siltic, Skeletic)), cell forms (Turbic Cryosol (Siltic, Skeletic)), and sorted circles (Turbic Cryosol (Skeletic)), respectively. In the 10-15 cm layer, the shape of water conductivity curves for the higher values of water potentials is nearly the same as for the upper layer. Similarly, the water conductivity is the highest - 0.2 cm day-1 for tundra polygons. For the lower water potentials, the differences in water conductivity increase to the decrease of soil water potential. At the lowest potential the water conductivity is the highest for sorted circles - 0.02 cm day-1 and the lowest in tundra polygons - 0.00002 cm day-1.

Water retention of arctic zone soils (Spitsbergen)

Abstract The water retention characteristics of the arctic zone soils ((TurbicCryosol (Skeletic), TurbicCryosols (Siltic, Skeletic) and BrunicTurbicCryosol (Arenic)) derived in different micro-relief forms were determined. Water retention curves were similar in their course for the mud boils, cell forms, and sorted circles ie for TurbicCryosols. For these forms, the mud boils showed the highest water retention ability, whereas the sorted circles - the lowest one. Water retention curves for the tundra polygons (Brunic TurbicCryosol, Arenic) were substantially different from these mentioned above. The tundra polygons were characterized by the lowest bulk density of 1.26 g cm-3, whereas the sorted circles (TurbicCryosol, Skeletic) - the highest: 1.88 g cm-3. Total porosity was the highest for the tundra polygons (52.4 and 55.5%) and the lowest - for the sorted circles (28.8 and 26.2%). Pore size distribution of the investigated soils showed that independently of depths, the highest content of large and medium pores was noticed for the tundra polygons ie 21.2-24.2 and 19.9-18.7%, respectively. The lowest content of large pores was observed for the cell forms (6.4-5.9%) whereas the mud boils exhibited the lowest amount of medium sized pores (12.2-10.4%) (both TurbicCryosols Siltic, Skeletic). The highest content of small pores was detected in the mud boils - 20.4 and 19.0%.

Hydrophysical characteristics of selected soils from arctic and temperate zones

Abstract Hydrophysical characteristics of arctic and temperate zones soils were determined. The soils from the temperate zone showed a greater capability of water retention than those from the arctic zone. In both investigated depths (surface and subsurface layers), the highest water content was observed for the Sądecki Regosol, and the lowest one for Turbic Cryosol formed in the cell forms from Spitsbergen at all soil water potentials. The differences between water content for these soils at the same soil water potentials varied between 20 and 25% vol. in the surface layer, and from 19 to 22% vol. in the subsurface, respectively. The lowest differences (2.7-5.0% vol.) in water content were noticed between the Wyspowy Regosol and Turbic Cryosol (Skeletic) derived in the sorted circles. In both depths, higher values of water conductivity were observed for Regosols than for Cryosols at high soil water potentials, from -0.1 till -7 kJ m-3. These differences were especially high at -0.1 kJ m-3 and they were three or four times higher for soils from the temperate zone than from the arctic ones. For lower water potentials, the differences in water conductivity do not exceed one order in the surface layer and two orders in the subsurface.

Adsorption of water vapour and the specific surface area of arctic zone soils (Spitsbergen)

Abstract Water vapour/nitrogen adsorption were investigated and calculated the specific surface areas of arctic-zone soil samples (Turbic Cryosols) originating from different micro-relief forms (mud boils, cell forms and sorted circles) and from different depths. For the characterisation of the isotherms obtained for arctic soils, the Brunauer-Emmet-Teller model was then compared with the two other models (Aranovich-Donohue and Guggenheim-Anderson-de Boer) which were developed from Brunauer-Emmet-Teller. Specific surface area was calculated using the Brunauer-Emmet-Teller model at p p0−1 range of 0.05-0.35 for the water vapour desorption and nitrogen adsorption isotherms. The values of total specific surface area were the highest in Cryosols on mud boils, lower on cell forms, and the lowest on sorted circles. Such tendency was observed for the results obtained by both the water vapour and nitrogen adsorption. The differences in the values of specific surface area at two investigated layers were small. High determination coefficients were obtained for relationships between the specific surface areas and contents of clay and silt fraction in Cryosols. No statistically significant correlation between the total carbon amount and the values of specific surface area in Cryosols has been found.