Comparison of two-year and immediate effect of biochar application on soil hydrophysical properties of haplic cambisol

Komronbek Yusupov

Master's thesis

Abstract:

Biochar is solid material obtained from thermochemical conversion of biomass in an oxygen-limited environment. Biochar can be used for range of application as an agent for soil improvement, improved resource use efficiency, remediation and protection against particular environmental pollution and as avenue for greenhouse gas mitigation.Biochar improves almost any soil, especially areas with low rainfall or nutrient-poor soils will most likely see the largest impact from addition of the biochar. However, long-term effect of biochar is not studied well in the Czech Republic. The aim of the study was to compare immediate and long-term effect of biochar on soil hydrophysical properties of haplic cambisol. The thesis was based on laboratory experiments, which were carried out in laboratory of the Department of Water Resources on repacked soil core samples with the volume of 250 cm3. Haplic cambisol was taken at the experimental site of Research Institute for Soil and Water Conservation in Prague-Zbraslav in Třebsín, where biochar was applied two years ago, approx. 12 t/ha. . Three variants of biochar application were studied as follows: (1) no biochar admixture (control variant), (2) biochar admixture of 1% by mass, which was added to the soil in lab before the measurements, and (3) about 0.6% of biochar applied to the field two years ago. In addition, pure biochar was studied as well. Soil hydrophysical properties; saturated soil hydraulic conductivity (Ks) and soil water retention curve (SWRC) were measured both at the same sample by employing falling head method and evaporation method, respectively, with at least three replicates. Constant dry bulk density (BD) was maintained during the measurements, however, two BD values were tested.From the obtained results for Ks, it was seen that BD affects the Ks value much more than biochar particles. Therefore, samples prepared with lower BD (1.2 g/cm3) showed significantly higher Ks values. Samples with higher BD (1.4 g/cm3) showed statistically significantly higher Ks for the variant (3) compared to (2) while there was no significant difference between (1) and (3).SWRC is affected in the part close to saturation up to pF 1.5. Results showed that there is no much difference between (1) and (2); however, variant (2) has insignificantly higher water retention. On the other hand, increase in (3) (field application) was considerable.

Keywords

cambisol, saturated hydraulic conductivity, soil water retention curve, biochar

Language used: English

Date on which the thesis was submitted / produced: 27. 4. 2018

Thesis defence

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

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Master programme / field:
Natural Resources and Environment / Natural Resources and Environment