Pedosphere 25(3): 468--477, 2015
ISSN 1002-0160/CN 32-1315/P
©2015 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Soil wetting patterns and water distribution as affected by irrigation for uncropped ridges and furrows |
ZHANG Yong-Yong1,2,3, ZHAO Xi-Ning3 and WU Pu-Te3 |
1Linze Inland River Basin Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000 (China)
2Key Laboratory of Eco-hydrology of Inland River Basin, Chinese Academy of Sciences, Lanzhou 730000 (China)
3Institute of Water Saving Agriculture in Arid regions of China, Northwest A & F University, Yangling 712100 (China) |
| ABSTRACT |
| The ridge-furrow tillage combined with furrow irrigation is being more widely applied and has been shown to be effective in the Loess Plateau of China. Accurate characterization of water infiltration behavior under ridge-furrow irrigation could provide guidelines and criteria for future irrigation system design and operation. Our objective was to investigate soil water behavior during ponding infiltration in a cross-sectional ridge-furrow configuration. Soil water movement within three different soil textures was tested by tracking the spatial and temporal soil water content (SWC) variations in a soil chamber. The two-dimensional transient flow initially transferred rapidly, but gradually decreased with elapsed infiltration time, approaching a stable flow after 90 min. A technical parameter equation incorporating the Philip equation was developed using the water balance method to accurately predict total applied water volume (TAWV). The wetting patterns moved outward in an elliptical shape. The wetted lateral and downward distances fitted using equations accounted for capillary and gravitational driving forces in variably wetted soil media. Increasing initial SWC resulted in an increase in wetted soil volume, which can also be caused by decreasing bulk density in a homogeneous soil. Higher water level produced greater wetted lateral distance and more irrigation uniformity. The wetted lateral distance was almost identical to the wetted depth in silty clay loam soil; hence ridge-furrow irrigation should be implemented in such finer-textured soils. The wetted soil volume differed markedly among different soil textures (hydraulic properties), demonstrating that these properties can largely determine soil water spreading patterns and distribution. |
| Key Words: infiltration, ridge-furrow tillage, soil texture, soil water content, technical parameter equation, wetted soil volume |
| Citation: Zhang, Y. Y., Zhao, X. N. and Wu, P. T. 2015. Soil wetting patterns and water distribution as affected by irrigation for uncropped ridges and furrows. Pedosphere. 25(3): 468-477. |
| |
|
View Full Text
|
|
|
|
