Effect of Saline Water for Drip Irrigation on Microbial Diversity and on Fertility of Aeolian Sandy Soils

Abstract

Saline water is widely distributed in the arid environment and sometimes represents the only source of irrigation water to restore and reconstruct vegetation. However, the effects of saline water on the bacterial diversity and fertility level of aeolian sandy soil are not well understood. In this study, we investigated a vegetation belt along the Tarim Desert Highway that has been constructed as a windbreak and consists of desert shrubs and was irrigated with saline water at six levels of salinity along the Tarim Desert Highway. The bacterial diversity was studied using Biolog Eco, a phospholipid fatty acid analysis, and a polymerase chain reaction–denaturing gradient gel electrophoresis, and the soil fertility was calculated and expressed as the integrated fertility index. The soil bacterial diversity (in terms of carbon metabolism, genes, and fatty acid species) was significantly affected by the level of salinity, and the microbial activity was low under high salinity. Fertility was also markedly affected by the degree of salinity and by the depth of soil, being lower at higher salinity levels and in the top layer (0–5 cm), and was also correlated to both the metabolic diversity index of soil microorganisms and the diversity index of fatty acids of soil microorganisms. The genetic diversity index of soil microorganisms shared a polynomial relation with fertility and contributed to it positively and significantly. Therefore, using less saline water for drip irrigation could avoid salt accumulation in soil and arrest its compaction, promote the formation of soil aggregates and the build-up of nutrients, and increase microbial activity, thus playing a crucial role in promoting the circulation, conversion, and utilization of nutrients in aeolian sandy soils and improving the soil quality. The judicious use of saline water, therefore, deserves serious consideration in irrigation practices.

Irrigation water salinity structures the bacterial communities of date palm (Phoenix dactylifera)-associated bulk soil

“…Soil salinity is an important determinant of bacterial richness ( Zhang et al, 2019 ; Li et al, 2021b ) and Shannon diversity index ( Guo et al, 2021 ; Yu et al, 2021 ; Nan et al, 2022 ) in arid ecosystems. Apart from soil salinity, irrigation water salinity also affect the Shannon diversity index, both negatively ( Zheng et al, 2017 ; Chen et al, 2019 ; Hou et al, 2021 ) and positively ( Chen et al, 2017 ) in arid soil.…”

Salinity and hydraulic retention time induce membrane phospholipid acyl chain remodeling in Halanaerobium congolense WG10 and mixed cultures from hydraulically fractured shale wells

“…Natural causes of soil salinization include mineral weathering, dissolution of fossil salts, rain deposition, and upwards migration of saline groundwater by capillary action ( Das et al, 2020 ). Moreover, anthropogenic management practices especially irrigation, represent a significant source of inorganic salts to soils ( Yu et al, 2021 ). Salinity levels beyond their tolerance thresholds challenge the viability and physiologies of plants and microorganisms, which dominate the biota of the soil matrix.…”

“…Salinity levels beyond their tolerance thresholds challenge the viability and physiologies of plants and microorganisms, which dominate the biota of the soil matrix. Several studies have linked high salinity to reduced microbial diversity in forest, desert and agro-based systems ( Rath et al, 2019 ; Zhang et al, 2019 ; Yu et al, 2021 ). In addition, the availability of micronutrients such as iron (Fe) to plants is impeded by high salt levels ( Abbas et al, 2015 ; Singh et al, 2022 ).…”