黄土丘陵区农耕地与撂荒地土壤水分特征及对降雨的响应分析

Soil moisture characteristics and their response to rainfall in cultivated land and abandoned land in loess hilly region

土壤水分是黄土丘陵区植被恢复和生态建设的重要限制因子,其对植被的生长状况具有重要的影响。植被恢复工程的推进和区域城镇化的提速,致使大量农耕地被撂荒,为探明人工恢复和自然恢复对黄土丘陵区土壤水分的影响,选取山西省冯家沟农耕地和撂荒地作为研究对象,基于2018-11月至2019-10月逐日降雨量和土壤含水量的长期观测数据,系统分析了土壤水分的动态变化规律及对降雨变化的响应过程。结果表明:1)农耕地各月土壤含水量均大于撂荒地且差异显著(p<0.05)。农耕地各土层土壤含水量均大于撂荒地且差异显著(p<0.05),农耕地最大含水量出现在40~60cm土层,而撂荒地最大含水量在20~40cm土层。2)除35.3mm降雨外农耕地和撂荒地随着降雨量的增加土壤含水量的增加量和土层的响应深度均呈增加的趋势。研究发现适当的人工恢复比自然恢复更有利于土壤水分的储存,为黄土高原东部地区农业生产和植被恢复提供一定的理论数据支持。

Soil moisture is an important limiting factor for vegetation restoration and ecological construction in loess hilly areas, which has an important impact on the growth of vegetation. The advancement of vegetation restoration project and the acceleration of regional urbanization have led to the abandonment of a large number of cultivated land. In order to explore the influence of artificial restoration and natural restoration on soil moisture in loess hilly region, cultivated land and abandoned land in Fengjiagou, Shanxi Province were selected as the research objects in this study. Based on the observation data of daily rainfall and soil moisture from November 2018 to October 2019, dynamic change law of soil moisture and its response to rainfall change were systematically analyzed. The results showed that: 1) The soil water content of cultivated land was higher than that of abandoned land in each month and the difference was significant(p<0.05). The soil water content of each soil layer in cultivated land was higher than that in abandoned land and the difference was significant(p<0.05). The maximum water content of cultivated land appeared in 40~60 cm soil layer, while the maximum water content of abandoned land was in 20~40 cm soil layer. 2) Except for 35.3 mm rainfall, the increase of soil water content and the response depth of soil layer in cultivated land and abandoned land increased with the increase of rainfall. This study found that appropriate artificial restoration was more conducive to the storage of soil moisture than natural restoration, which provided certain theoretical data support for agricultural production and vegetation restoration in the eastern Loess Plateau.