College of Hydraulic Science and Engineering, Yangzhou University, Yangzhou, Jiangsu, China.
Institute of Water-saving Agriculture in Arid Areas of China, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China.
PeerJ. 2022 Jul 14;10:e13736. doi: 10.7717/peerj.13736. eCollection 2022.
Changes in soil moisture and soil temperature result from the combined effects of several environmental factors. Scientific determination of the response characteristics of soil moisture and soil temperature to environmental factors is critical for adjusting the sloping land use structure and improving the ecological environment in China's loess hilly region. Soybean sloping fields, maize terraced fields, jujube orchards, and grasslands in the loess hilly region were selected as the research areas. The change in characteristics of soil moisture and soil temperature, as well as their interactions and statistical relationships with meteorological factors, were analyzed using continuously measured soil moisture, soil temperature, and meteorological factors. The results revealed that air temperature and humidity were the main controlling factors affecting soil moisture changes in the 0-60 cm soil layer of soybean sloping fields and grasslands in the normal precipitation year (2014) and the dry year (2015). Humidity and wind speed were the main meteorological factors affecting soil moisture changes in the maize terraced field. Air temperature had a significant negative effect on soil moisture in the jujube orchard. Soil moisture and soil temperature were all negatively correlated under the four sloping land use types. In normal precipitation years, atmospheric humidity had the greatest direct and comprehensive effect on soil moisture in soybean sloping fields, maize terraced fields, and grasslands; soil temperature had a relatively large impact on soil moisture in jujube orchards. The direct and comprehensive effects of soil temperature on soil moisture under all sloping land use types were the largest and most negative in the dry year. Air temperature had a high correlation with soil temperature in the 0-60 cm soil layer under the four sloping land use types, and the grey relational grade decreased as the soil layer deepened. The coefficient of determination between the 0-20 cm soil temperature and air temperature in the maize terraced field was low, indicating a weak response to air temperature. The above findings can serve as a scientific foundation for optimizing sloping land use structures and maximizing the efficient and sustainable utilization of sloping land resources in China's loess hilly region.
土壤水分和土壤温度的变化是由多种环境因素共同作用的结果。科学确定土壤水分和土壤温度对环境因素的响应特征，对于调整黄土丘陵区坡地利用结构、改善生态环境具有重要意义。选择黄土丘陵区的大豆坡地、玉米梯田、枣园和草地作为研究区域。利用连续测量的土壤水分、土壤温度和气象因子，分析了土壤水分和土壤温度特征的变化及其与气象因子的相互作用和统计关系。结果表明，气温和湿度是正常降水年（2014 年）和干旱年（2015 年）大豆坡地和草地 0-60cm 土层土壤水分变化的主要控制因素。湿度和风速是玉米梯田土壤水分变化的主要气象因素。空气温度对枣园土壤水分有显著的负效应。在四种坡地利用类型下，土壤水分和土壤温度均呈负相关。在正常降水年，大气湿度对大豆坡地、玉米梯田和草地土壤水分的直接和综合影响最大；土壤温度对枣园土壤水分的影响较大。在干旱年，土壤温度对所有坡地利用类型下土壤水分的直接和综合影响最大且最负。在四种坡地利用类型下，0-60cm 土层的空气温度与土壤温度相关性较高，随着土层的加深，灰色关联度逐渐降低。玉米梯田 0-20cm 土壤温度与空气温度的决定系数较低，表明对空气温度的响应较弱。上述研究结果可为优化坡地利用结构、实现黄土丘陵区坡地资源高效可持续利用提供科学依据。
