摘要
[目的]探究宁夏南部黄土丘陵区雨养苜蓿及柠条地的深层根系与土壤水分和养分的协同关系,进而为宁南山区人工植被建设与管理以及生态环境高质量发展提供科学依据。[方法]采用野外调查与室内分析相结合的方法,对宁南黄土丘陵区人工种植18 a的紫花苜蓿地与20 a的柠条林地0—1000 cm土层中土壤水分、根系垂直分布、土壤N,P含量变化进行了分析。[结果](1)苜蓿地和柠条林地土壤200 cm以下全剖面已经处于干化状态,其中苜蓿和柠条地土壤处于极度干燥化水平的土层分别为200—720 cm和360—720 cm,0—1000 cm深度范围土壤水分储量较相似地形的雨养农田分别少987.55,977.78 mm;(2)苜蓿和柠条根系主要集中在表层0—120 cm土层,该层根系占0—1000 cm剖面总根干重的45.66%,57.54%,根长密度占44.45%,67.58%;(3)苜蓿和柠条土壤N,P养分分布规律与根系分布规律一致,表层0—120 cm范围内平均全N含量分别为0.53,0.58 g/kg,是0—1000 cm土壤全N含量平均值的1.77倍和1.87倍,在0—120 cm范围内全P平均含量达0.51,0.53 g/kg,与0—1000 cm土层全P含量平均值近似。[结论]黄土丘陵区深层土壤干化背景下人工林草地土壤水分、根系及养分特征具有特殊性,深入研究人工林草地深层土壤水分、根系及养分协同关系有助于区域人工植被可持续发展及土壤碳循环的调控。
[Objective]The aims of this study are to explore the synergistic relationship between deep roots and soil moisture and nutrients in rainfed Medicago sativa L.and Caragana korshinskii land in the loess hilly area of southern Ningxia,and to provide scientific basis for the construction and management of artificial vegetation and the high-quality development of ecological environment in the hilly area of southern Ningxia.[Methods]The changes of soil moisture,root vertical distribution and soil N and P contents in 0—1000 cm soil layer of 18-year-old Medicago sativa L.land and 20-year-old Caragana korshinskii forest land were analyzed by field investigation and indoor analysis.[Results](1)The whole profile of soil below 200 cm in Medicago sativa L.land and Caragana korshinskii land was already in a dry state.The soil layers of Medicago sativa L.land and Caragana korshinskii land at extremely dry levels were 200—720 cm and 360—720 cm,respectively.The soil water storage in the depth range of 0—1000 cm was 987.55 mm and 977.78 mm and less than that of rainfed farmland with similar topography.(2)The roots of Medicago sativa L.and Caragana korshinskii mainly concentrated in the 0—120 cm soil layer,which accounted for 45.66%and 57.54%of the total root dry weight in the 0—1000 cm profile,and the root length density accounted for 44.45%and 67.58%.(3)The distribution of N and P nutrients in the soil of Medicago sativa L.and Caragana korshinskii lands was consistent with that of root system.The average total N content in the surface layer of 0—120 cm was 0.53 g/kg and 0.58 g/kg,respectively,which was 1.77 times and 1.87 times of the average total N content in the soil of 0—1000 cm.The average total P content in the range of 0—120 cm was 0.51 g/kg and 0.53 g/kg,which was similar to the average total P content in the 0—1000 cm soil layer.[Conclusion]The characteristics of soil moisture,root system and nutrient of artificial forest and grassland under the background of deep soil drying in the loess hilly area a
作者
高元亢
李婧
汪星
吕雯
于晓燕
王雁超
王永强
Gao Yuankang;Li Jing;Wang Xing;LüWen;Yu Xiaoyan;Wang Yanchao;Wang Yongqiang(School of Agriculture,Ningxia University,Yinchuan 750021,China;Yinchuan Customs Technology Center,Yinchuan 750000,China;School of Ecology and Environment,Ningxia University,Yinchuan 750021,China)
出处
《水土保持研究》
CSCD
北大核心
2023年第6期168-176,共9页
Research of Soil and Water Conservation
基金
宁夏自然科学基金(2022AAC05019,2021AAC03042)
国家自然科学基金(32060301)。
