Gao Yongfei, Yang Pengyuan
College of Ecology, Taiyuan University of Technology, Taiyuan 030024, PR China; Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, PR China.
College of Grain, Jilin Business and Technology College, Jilin 130507, PR China.
Sci Total Environ. 2023 Dec 15;904:166700. doi: 10.1016/j.scitotenv.2023.166700. Epub 2023 Sep 1.
In grassland soils, soil water repellency (SWR) may be one of the triggers of soil erosion and degradation as it can reduce water infiltration and penetration into the soil. Few studies were focusing on the evaluation of soil hydro-physical properties, such as hydrophobicity, and their relation to soil moisture, hydrophobic matter, and particle size in grassland soils. In this study, 800 soil samples were collected from the Xilingol grassland in Inner Mongolia, China, using the water droplet penetration time (WDPT) test to evaluate water repellency and we aimed to investigate the temporal and spatial distribution of SWR in grassland soils using the Kriging and Inverse Distance Weighting (IDW) interpolation methods and determine the physical-chemical properties that trigger the SWR. The results showed that the grassland soils in the studied area were slightly water-repellent and a few portions of the area exhibited strong water-repellency. In April, areas of soils with a depth of 0-5 cm and slight to strong SWR accounted for 80 % of the total studied area, of which 5 % had strong water repellency. Moreover, in August, 90 % of the studied area consisted of soils with slight to strong SWR, of which 60 % accounted for soils with strong SWR. With a soil water content of 10.95 %, the SWR reached its peak, with an average value of 60.32 s. The SWR was positively correlated with total N, available N, and soil organic matter (SOM) contents, and therein the hydrophobic acid matter and the hydrophobic basic matter content had a positive contribution to SWR, and the hydrophilic basic matter and the hydrophilic acidic matter had a negative contribution on SWR. In addition, SWR was found to be negatively related to the soil particle size (r = -0.672). A slight SWR was also observed in the majority of the studied area, particularly in the topsoil and fine soils, especially during the monsoon period; hence, SWR must be also considered to reduce the risk of occurrence of soil erosion and degradation in grasslands.
在草原土壤中,土壤斥水性(SWR)可能是土壤侵蚀和退化的触发因素之一,因为它会减少水分渗入和穿透土壤的能力。很少有研究关注草原土壤的水文物理性质评估,如疏水性,以及它们与土壤湿度、疏水物质和颗粒大小的关系。在本研究中,从中国内蒙古锡林郭勒草原采集了800个土壤样本,采用水滴渗透时间(WDPT)试验评估斥水性,我们旨在使用克里金法和反距离加权(IDW)插值方法研究草原土壤中SWR的时空分布,并确定触发SWR的物理化学性质。结果表明,研究区域的草原土壤具有轻微的斥水性,该区域的一些部分表现出较强的斥水性。4月,深度为0 - 5厘米、具有轻微至强烈SWR的土壤面积占研究总面积的80%,其中5%具有强斥水性。此外,8月,90%的研究区域由具有轻微至强烈SWR的土壤组成,其中60%为具有强SWR的土壤。当土壤含水量为10.95%时,SWR达到峰值,平均值为60.32秒。SWR与全氮、有效氮和土壤有机质(SOM)含量呈正相关,其中疏水酸性物质和疏水碱性物质含量对SWR有正向贡献,而亲水碱性物质和亲水酸性物质对SWR有负向贡献。此外,发现SWR与土壤颗粒大小呈负相关(r = -0.672)。在研究区域的大部分地区,特别是在表土和细粒土壤中,尤其在季风期也观察到轻微的SWR;因此,为降低草原土壤侵蚀和退化的发生风险,也必须考虑SWR。