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Infiltration characteristics in sloping farmland at different growth stages of soybean (Glycine max L. ) in loess area |
Wang Linhua1, Ma Bo2, Wu Faqi3 |
1. Institute of Soil and Water Conservation, Northwest A&F University, 712100, Yangling, Shaanxi, China; 2. Institute of Soil and Water Conservation, Chinese Academy of Science, Ministry of Water Resources, 712100, Yangling, Shaanxi, China; 3. College of Resources and Environments, Northwest A&F University, 712100, Yangling, Shaanxi, China |
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Abstract Soil erosion in sloping farmland is a key ecological and environmental issue that threats thesustainable agricultural development on the Loess Plateau of China. Knowledge of infiltration process is crucial for understanding and managing hydrological processes and soil erosion in sloping farmland. The objective of this study was to clarify the infiltration characteristics in sloping farmland at different stages of crop growth. The soybean (Glycine max L. ) was selected as our research object and its growth was divided into four stages: initial flowering stage (R1 ), late flowering stage (R2 ), pod bearing stage (R4), and maturity starting stage (R5 ). The bare sloping farmland was set as control (CK). Runoff from experimental plots was collected under the simulated rainfall condition, the infiltration processes and characteristics were analyzed, and the infiltration processes were simulated with the Horton and Kostiakov infiltration models. The following results were obtained. For the four growth stages of soybean, parameters such as initial infiltration rate, stable infiltration rate, cumulative infiltration amount and infiltration recharge coefficient presented generally the order as R5 > R4 > R2 > R1 > CK at different rainfall intensities and slope gradients. The recharge coefficient increased with growth stages but decreased with slope gradient. The crop coverage was the important factor for determining the recharge coefficient. Simulated infiltration processes with Horton and Kostiakov models showed that two models fit well with the infiltration and could reflect the infiltration characteristics while the fitting effect of Horton was better than Kostiakov. The results of our study are helpful for better understanding of the infiltration processes and characteristics in sloping farmland during the crop growth stages.
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Received: 13 October 2014
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