Applicability of five models to simulate water infiltration into soil with added biochar

Authors: WANG, TONGTONG - Northwest Agricultural & Forestry University; Stewart, Catherine; MA, JIANGBO - Northwest Agricultural & Forestry University; ZHENG, JIYONG - Northwest Agricultural & Forestry University; ZHANG, XINGCHANG - Northwest Agricultural & Forestry University

Submitted to: Journal of Arid Land
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/2/2017
Publication Date: 6/28/2017
Citation: Wang, T., Stewart, C.E., Ma, J., Zheng, J., Zhang, X. 2017. Applicability of five models to simulate water infiltration into soil with added biochar. Journal of Arid Land. doi:10.1007/s40333-017-0025-3.
DOI: https://doi.org/10.1007/s40333-017-0025-3

Interpretive Summary: As a soil amendment, biochar can reduce soil bulk density, increase soil porosity, and alter soil aggregates and thus affect the infiltration. A laboratory experiment was performed to study the infiltration characteristics of two typical Loess Plateau soils at three particle sizes (2–1, 1–0.25, and <0.25 mm) and five biochar application amounts (0, 10, 50, 100, and 150 g/kg). The performance of five models in simulating the infiltration process was then evaluated based on the adjusted coefficient of determination and a reduced Chi-Square test. The three-parameter model can better describe the relationship between cumulative infiltration and infiltration time. In conclusion, biochar reduced the soil infiltration capacity of the Aeolian sandy soil and increased that of the Eum-Orthic Anthrosol.

Technical Abstract: As a soil amendment, biochar can reduce soil bulk density, increase soil porosity, and alter soil aggregates and thus affect the infiltration. Researchers have proposed and revised several theoretical models to describe the process of soil infiltration. Although these models have been successfully used to evaluate the soil infiltration in different scenarios in agricultural fields, little effort has been devoted to assess their performances in arid and semi-arid soils after the addition of biochar. A laboratory experiment was performed to study the infiltration characteristics of two typical Loess Plateau soils at three particle sizes (2–1, 1–0.25, and <0.25 mm) and five biochar application amounts (0, 10, 50, 100, and 150 g/kg). The performance of five models (i.e., the Philip model, Kostiakov model, Mezencev model, USDA-NRCS model, and Horton model) in simulating the infiltration process was then evaluated based on the adjusted coefficient of determination and a reduced Chi-Square test. Results indicated that the Horton model best simulated the water-infiltration process in an aeolian sandy soil with added biochar. However, the Mezencev model best simulated the infiltration process in a loamy clay soil (Eum-Orthic Anthrosol). The three-parameter model can better describe the relationship between cumulative infiltration and infiltration time. In conclusion, biochar reduced the soil infiltration capacity of the Aeolian sandy soil and increased that of the Eum-Orthic Anthrosol.