The effect of biochar admixture on the saturated hydraulic conductivity of several soils

B.Sc. Adam Dziadula, BS

Master's thesis

Abstract:

Biochar is an organic, carbon-rich material that has proven its potential for soil quality enhancement by practical applications. The aim of this thesis was to examine the ability of biochar admixture to stimulate the saturated hydraulic conductivity (Ks) of several soil types from the Czech Republic.Disturbed soil samples were collected, homogenized, and treated with different concentrations of biochar to observe its effect on Ks on each soil type using the 250 cm3 repacked soil samples carried out under controlled laboratory conditions on a falling head permeameter. The chosen soils for this experiment were; (1) a standard fine silica sand, (2) a light cambisol, (3) a silty-loam chernozem, and (4) a clay-loam luvisol. All of these soil types vary in physical and other soil properties. The biochar treatments applied to the samples were as follows; (1) no biochar admixture (control), (2) addition of 0.001 g/g, and (3) 0.01 g/g of biochar, corresponding to application rates of 3 t/ha and 30 t/ha respectively. Each level of treatment was carried out in three replicates. The samples were measured immediately after repacking.The various physical properties of soils reflect the specific properties of biochar itself. By testing its influence on homogenized soil samples under distinct conditions a clear relationship was drawn not only between biochar concentration and its influence on hydraulic properties, but how the achieved hydraulic properties were correlated with bulk density and porosity. Once these relationships were defined, a clear trend of biochar mechanisms was observed. The results showed statistically significant decrease of Ks in case of light soils (from 77 to 32 cm/d in cambisol and from 743 to 524 cm/d in sand) and increase in the case of heavier soils. The rising biochar concentrations increased the Ks value of the chernozem (from 182 cm/d to 182 and then to 245 cm/d), but did not differ significantly for either of the light soils.

Keywords

biochar, saturated hydraulic conductivity, bulk density, homogenized soil sample, falling head permeameter

Language used: English

Date on which the thesis was submitted / produced: 1. 4. 2017

Thesis defence

• Supervisor: Ing. Markéta Miháliková, Ph.D.

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme / field:
Technology and Environmental Engineering / Technology and Environmental Engineering