Characteristics of soil water infiltration in replanted alfalfa plots after severe drying of deep soil horizons in loess areas
Natural precipitation is the only water source in the semi-arid loess region.This research investigated the characteristics of soil water infiltration following precipitation after replanting deep-rooted,perennial plants in soil with severely depleted moisture levels in the hilly areas of the Loess Plateau.Specifically,the research simulated the cultivation of Medicago sativa,using large-scale soil columns(lysimeters)at the Wangwa Soil and Water Conservation Experiment Station in southern Ningxia.The simulation experiment was based on actual rainfall data from March to October in 2022-2023.The results indicated that:1)Only 41.67% of all precipitation events resulted in soil water infiltration.The ratio of infiltration to precipitation varied with rainfall intensity:in light rain,moderate rain,heavy rain and torrential rain the infiltration was,respectively,15.89%,35.63%,52.20% and 61.50% of the total precipitation.Infiltration amounts thus showed an increasing trend with increasing precipitation.2)Precipitation infiltrating to depths of less than 30 cm,to depths of 30-80 cm,and to depths greater than 80 cm,accounted for,respectively,76.04%,18.75% and 5.21% of the total precipitation.3)With respect to the issue of deep soil water depletion,alfalfa cultivation led to a trend of soil water increase in soil water measured monthly for one year old plants,while for two year old plants,soil water measured monthly showed a decreasing trend.The monthly infiltration depth(Zm)increased with increasing monthly precipitation(Pm)as a quadratic function:Zm=-0.0101Pm2+3.9426Pm(R2=0.9895).The study provides data on deep soil water status,useful for planning the replanting and sustainable development of deep-rooted,perennial plants in areas on the Loess Plateau with severely dried deeper soil horizons.
国家科技期刊平台
NSTL
万方数据
