Measurements of Texture of Soils Formed from Glaciolimnic Sediments by Areometric Method, Pipette Method and Laser Diffraction Method
Abstract The aim of the research was to compare the results of texture analyses of glaciolimnic sediments deposited in the basins of ice-dammed lakes origin in north eastern Poland. The study was carried out using aerometric method, pipette method and laser diffraction method. The studied soils were classified as Haplic and Mollic Vertisol, Vertic Cambisol, and Gleyic Chernozem. The soils were formed from clayey (clay, heavy clay), loamy (loam, clay loam, sand clay loam) and silty (silt loam, clay loam) deposits. The studied soils did not contain fractions > 2.0 mm. The amounts of clay fraction (< 0.002 mm) measured by areometric and pipette methods were similar and strongly correlated. In comparison to laser diffraction method, these amounts were 3-4-fold higher. The sub-fraction of fine silt (0.02-0.002 mm) predominated in soil formations analyzed by laser diffraction method. In comparison to areometric or pipette method, the amounts of fine silt were 2-4 fold higher. Basing on the calculated sedimentological indices, it was stated that the examined soils were well sorted and the mean grain diameter (GSS) was very low and did not exceed 0.005 mm in areometric and pipette methods, and 0.011 mm in laser diffraction method for clay sediments.
Clay minerals from Weichselian glaciolimnic sediments of the Sępopolska Plain (NE Poland)
Clay minerals from Weichselian glaciolimnic sediments of the Sępopolska Plain (NE Poland) Glaciolimnic deposits sampled from three sedimentation reservoirs located on the Sępopolska Plain (northeastern Poland) were investigated. The material under study was deposited in the recession phase of the Pomeranian phase of Vistula (Weichselian) glaciation. The clay fraction was separated by centrifugation after preparation according to Jackson. Mineralogical investigations were done by X-ray diffraction. The analysed deposits had a similar complex composition of clay minerals. The main components were illites mixed with the illite/smectite mineral with percentages < 10 % S. Another part were minerals of the illite/smectite type which had differentiated content of smectite layers (mainly 80-90 % S). There were also chlorite minerals, probably as mixed layer minerals of the chlorite/vermiculite type or HIV with a negligible amount of chlorite layers. The results indicated that all the deposits were of the same age as well as similar deposited material and the samples are different from typical Pomeranian till and typical limnic material of the same age. Small differences observed among the deposits of specific sedimentation reservoirs were probably the result of later processes.
Soil physical properties as affected by traditional, reduced and no-tillage for winter wheat
A b s t r a c t. The aim of this research was to determine the effects of traditional, reduced and no-tillage systems on the soil physical properties: bulk density, water content, stability in water and soil physical quality. Traditional tillage involved soil inversion whereas reduced tillage and no-tillage were non-inversion systems. Soil physical properties were measured on samples collected from the field throughout the growing season and harvest times. These included: particle size distribution, soil water content and bulk density. Soil stability was measured in terms of the content of readily-dispersible clay (RDC) in the soil samples. From water retention curves, an index of soil physical quality (S index) was calculated. The effect of tillage systems on the values of the physical properties was significant. The non-inversion plots (reduced tillage and no-tillage) increased water content and bulk density in the top layer in comparison with traditional tillage. Reduced tillage and no-tillage reduced the amount of RDC and therefore increased soil stability, especially in the top layer in comparison with traditional tillage. Reduced tillage and no-tillage also decreased the S index after the first year in comparison with traditional tillage. However, after 4 years, the non-inversion plots (reduced tillage and no- tillage) showed some improvement in soil physical quality and soil stability in water. K e y w o r d s: tillage systems, bulk density, water content, soil stability in water, readily-dispersible clay, soil physical quality