title: Spatial Variations of Soil Microbial Activities in Saline Groundwater-Irrigated Soil Ecosystem.
abstract: Spatial variations of soil microbial activities and its relationship with environmental factors are very important for estimating regional soil ecosystem function. Based on field samplings in a typical saline groundwater-irrigated region, spatial variations of soil microbial metabolic activities were investigated. Combined with groundwater quality analysis, the relationship between microbial activities and water salinity was also studied. The results demonstrated that moderate spatial heterogeneity of soil microbial activities presented under the total dissolved solids (TDS) of groundwater ranging from 0.23 to 12.24 g L(-1). Groundwater salinity and microbial activities had almost opposite distribution characteristics: slight saline water was mainly distributed in west Baqu and south Quanshan, while severe saline and briny water were dominant in east Baqu and west Huqu; however, total AWCD was higher in the east-center and southwest of Baqu and east Huqu, while it was lower in east Baqu and northwest Huqu. The results of correlation analyses demonstrated that high-salinity groundwater irrigation had significantly adverse effects on soil microbial activities. Major ions Ca(2+), Mg(2+), Cl(-), and SO4(2-) in groundwater decisively influenced the results. Three carbon sources, carbohydrates, amines, and phenols, which had minor utilization rates in all irrigation districts, were extremely significantly affected by high-salinity groundwater irrigation. The results presented here offer an approach for diagnosing regional soil ecosystem function changes under saline water irrigation.
authors.affiliation: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000, China. qifeng@lzb.ac.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Feng
authors.affiliation: Plant Protection and Quarantine Station of Gansu Province, Lanzhou, 730020, China.
authors.forename: Chang-Sheng
authors.initials: CS
authors.lastname: Li
authors.affiliation: Engineering College, Gansu Agricultural University, Lanzhou, 730070, China.
authors.forename: You-Xi
authors.initials: YX
authors.lastname: Song
authors.affiliation: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000, China.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Si
authors.affiliation: Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, 730000, China.
authors.forename: Bao-Gui
authors.initials: BG
authors.lastname: Zhang
mesh_terms: D002681:China; D003889:Desert Climate; D017753:Ecosystem; D060587:Groundwater / Q000737:chemistry*; D054712:Salinity; D012988:Soil Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical
keywords: Desert oasis; Saline water irrigation; Soil microbial activities; Spatial variations