Abstract:
In order to explore the influence of gravel-mulched land with different planting years on soil water infiltration, the indoor vertical one-dimensional soil column infiltration test was used to analyze the gravel-mulched land with different planting years(2, 5, 10, 20, 30 and 40 a). Soil infiltration rate, cumulative infiltration volume and wetting front migration law were transformed into 4 infiltration models to fit the soil moisture infiltration process of gravel-mulched soil and evaluate its applicability, through a one-dimensional algebraic model and related parameters. The prediction results show that with the increase in sowing years, the cumulative soil infiltration amount, infiltration amount and the distance of the wet front movement are all significantly reduced. When the infiltration time is 300 min, compared with 2 years, the cumulative infiltration of 5, 10, 20, 30 and 40 a decreases by 27.01%, 43.32%, 53.22%, 54.79% and 54.68%, respectively, and the distance of wet front migration decreases by 24.84%, 38.38%, 48.56%, 52.67% and 54.00% respectively. The R~2 sequence of the four infiltration models is: Horton model> common experienced model> Kostiakov model> Philip model. The MAE between the soil profile scale values of different planting years fitted by the dimensional algebra model and the measured values are all between 0.48% and 2.09%, the RMSE are between 0.52% and 2.13%, D are all greater than 0.782, and t(test P values) were greater than 0.05, showing that it can better fit the water distribution of gravel-mulched land with different planting years. The longer the planting period of gravel-mulched land, the worse the water infiltration capacity and the lower the soil profile moisture content. It is recommended that the sustainable development of gravel-mulched land should be realized through measures such as strengthening management and fallow.