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| Effects of biochar on soil water transport characteristics of Heilu soil |
| WANG Youqi1,2, BAO Weibin1,2, BAI Yiru1,2*, LU Xuee1,2, XIA Zishu1,2, YANG Fan1,2, ZHONG Yanxia1,2 |
| 1. College of Resources and Environment, Ningxia University, Yinchuan, Ningxia 750021, China;2 Arid Area Characteristic Resources and Environmental Governance Department of Education International Cooperation Joint Laboratory, Yinchuan, Ningxia 750021, China |
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Abstract Biochar applied in soil can alter characteristic parameters of soil water migration in Helu soil in the southern Ningxia mountain region. In the paper, a typical Heilu soil in the region was selected to the study object. Then, a soil amendment-biochar was added into one-dimensional vertical and horizontal soil columns in four proportions, such as 0%, 1%, 2% and 3%, to explore the change in soil water transport characteristics, namely, infiltration rate, saturated volumetric water content, saturated hydraulic conductivity, and saturated diffusivity. The results showed that soil water content in the soils with 1%, 2% and 3% biochar was increased by 2.98%, 6.45% and 7.94% compared with the plain soil. The Philip model can reflect soil water transport process in different biochar mixing proportions more exactly than the Kostiakov model. The saturated volumetric water content in the amended soils with 1%, 2% and 3% biochar was increased by 5.05%, 8.33% and 9.85%, respectively, and the sa-turated hydraulic conductivity was decreased by 45.71%, 62.86% and 74.28%, respectively. The parameter a in the Van Gencuhten model for the amended soils with 1%, 2%, and 3% biochar was reduced by 31.90%, 29.25%, and 19.23%, and the parameter n in the model was reduced by 0.28%, 0.16%, and 0.66%, respectively. The saturated diffusivity in the amended soils with 1%, 2%, and 3% biochar was reduced by 58.46%, 77.96% and 89.28% compared with the plain soil, respectively. These facts suggest that biochar can improve soil structure, but also can increase soil volumetric water content and improve soil water holding capacity.
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Received: 08 July 2019
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