Shifts in soil microbial metabolic activities and community structures along a salinity gradient of irrigation water in a typical arid region of China

Shifts in soil microbial metabolic activities and community structures along a salinity gradient of irrigation water in a typical arid region of China

ChenLijuan ^a,b, LiChangsheng ^c, FengQi ^a?, WeiYongping^b, ZhengHang ^d,b, ZhaoYan^b, FengYongjiu ^e, LiHuiya ^a

a Key Laboratory of Ecohydrology of Inland River Basin, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China

b School of Earth and Environmental Sciences, The University of Queensland, Brisbane 4072, Australia

c Plant Protection and Quarantine Station of Gansu Province, Lanzhou 730020, China

d School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, Guangdong 523106, China

e College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China

a b s t r a c t

Saline water irrigation can change soil environment, which thereby influence soil microbial process. Based on a field experiment, the shifts in soil microbial metabolic activities and community structures under five irrigation salinities were studied using Biolog and metagenomic methods in this study. The results demonstrated that microbial metabolic activities were greatly restrained in saline water irrigated soils, as average well color development (AWCD) reduced under all saline water irrigation treatments. Although no significant difference in carbon substrate utilization of all six categories was observed among Mild, Medium, High and Severe treatments, the consumption of sole carbon source was significantly varied. Especially, asparagine, galacturonic, putrescine and 4-benzoic acid played a decisive role in dominating the differences. Soil bacterial richness and diversity increased with irrigation salinity while the number of bacterial phyla decreased. Three significantly increased (Proteobacteria, Actinobacteria and Chloroflexi), two decreased (Planctomycetes, Bacteroidetes) and two irresponsive (Gemmatimonadetes and Acidobacteria) phyla were observed as the dominant groups in saline water irrigated soils. The results presented here could improve the understanding of the soil biological process under saline circumstance.

全文.pdf