Soil hydrology is closely related to soil physical properties. Previous studies have shown that the soil physical properties were highly heterogenic in rubber-based agrogorestry. The correlation of soil physical properties and soil hydrological properties in rubber-based agroforestry should be quantified and analyzed. 

Researchers from Xishuangbanna Tropical Botanical Garden (XTBG) used dye-tracer infiltration to classify water flow behavior and HYDRUS-3D to interpret variation patterns of water flow behaviors in a rubber-based agroforestry system in Xishuangbanna, SW China. 

They utilized qualitative and quantitative methods to elucidate soil water flow behavior, infiltration properties, and water storage in different soil plots, including Hevea brasiliensis (HB), Citrus reticulata (CR), and no vegetation (NV) of a rubber-based agroforestry system. 

Variance analysis showed that the soil of forestry patches under Hevea brasiliensis and Citrus reticulata exhibited better soil physical properties (high field capacity, high saturated water-holding capacity, high saturated hydraulic conductivity), than soil physical properties in soil with no vegetation. 

The Citrus reticulata (CR) plots had the best connectivity of preferential flow path networks. Dye tracer infiltration indicated that the general infiltration capacity of the whole soil profile and the order of continuity and degree of connectivity of preferential flow path networks in the three plots followed the descending rank order of HB, CR, and NV. 

More importantly, the soil under HB and CR exhibited a faster downward wetting front; lateral flow occurred when soil was saturated by infiltration water. 

Water flow inducing by root of HB and CR compensated for the insufficient flow of NV. 

“Our findings indicated that the rubber-based agroforestry system is a successful approach for conserving water and reducing runoff in tropical regions”, said Prof. LIU Wenjie, principal investigator of the study. 

The study entitled “Use of dye infiltration experiments and HYDRUS-3D to interpret preferential flow in soil in a rubber-based agroforestry systems in Xishuangbanna, China” has been published in CATENA. 

Contact 

LIU Wenjie  Ph.D Principal Investigator  

Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China  

E-mail: lwj@xtbg.org.cn