Infiltration Characteristics of Topsoil in Reclamation Farmland Filled with Yellow River Sediment

Infiltration is an important indicator of water and nutrient holding capacity of soil. Lap infiltration apparatus was used to measure vertical water infiltration process in the third year of Yellow River sediment filling reclamation. Five infiltration models were selected to fit the infiltration characteristic curves, analyzed the infiltration experimental results during 3 years of reclamation. The results showed that, the mean initial infiltration rate and mean stable infiltration rate of filling farmland in the third year were 17.06mm/min and 2.38mm/min, and were 8.81mm/min and 0.99 mm/min higher than that of the first year, 3.58mm/min and 0.39mm/min higher than that of the second year. It indicated that, infiltration rate of filling farmland increased significantly after cultivation due to the farming practices and roots development, and the role of soil microorganisms and small animals. Filling farmland has some self-recovery capabilities. In addition, Kostiakov model has better fitting effect than Mezencev model for both filling farmland and control farmland.