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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Water Management Research » Research » Publications at this Location » Publication #309064

Research Project: Developing Sustainable Cropping Systems to Improve Water Productivity and Protect Water and Soil Quality in Irrigated Agriculture

Location: Water Management Research

Title: Microbial community biomass and structure in saline and non-saline soils associated with salt- and boron-tolerant poplar clones grown for the phytoremediation of selenium

Author
item Dangi, Sadikshya - University Of California
item Banuelos, Gary
item Buyer, Jeffrey
item Hanson, Bradley - University Of California
item Gerik, James

Submitted to: International Journal of Phytoremediation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/2017
Publication Date: 7/5/2017
Citation: Dangi, S.R., Banuelos, G.S., Buyer, J.S., Hanson, B.D., Gerik, J.S. 2017. Microbial community biomass and structure in saline and non-saline soils associated with salt- and boron-tolerant poplar clones grown for the phytoremediation of selenium. International Journal of Phytoremediation. 20(2):129-137. doi:10.1080/15226514.2017.1337073.
DOI: https://doi.org/10.1080/15226514.2017.1337073

Interpretive Summary: Soils in the west side of the San Joaquin Valley of California contain high levels of naturally occurring selenium, boron and other salts, and their effects on soil microbial community biomass and composition is not known. This information is important as soil microorganisms play an important role in ecosystem function and significantly contribute to nutrient cycling, organic matter decomposition, plant nutrient uptake, and maintenance of soil structure. The aim of this study was to examine and compare soil microbial communities in spring 2013, fall 2013, and winter 2014 for poplar trees grown in highly saline, boron and selenium soils, as well as in non-saline soils located in Parlier, California. In spring 2013, microbial biomass was lower in the saline soil compared to non-saline soil, but in fall 2013 and winter 2014, total biomass and all the microorganisms at saline sites, remained similar or higher than non-saline sites. Therefore, we conclude that an increase in the deposition of leaf litter at the saline site likely contributed to the sustainability of the soil microbial communities and biomass associated with growing poplar trees in high salt, boron and selenium soils.

Technical Abstract: The effect of naturally-occurring salts, boron (B), and selenium (Se) on soil microbial community composition associated with plants during different growing seasons used in bioremediation strategies is not known. This information is needed for developing sustainable remediation practices as soil microorganisms may play a vital role in sustaining health of soil and/or tolerance of plants grown in poor quality soils by contributing to nutrient cycling, soil structure, overall soil quality and plant survival. In this study, soil microbial communities were compared in spring 2013, fall 2013, and winter 2014 for poplar trees (Populus spp.) grown in highly saline, boron and selenium clay-like soils in the west side of the San Joaquin Valley of California, as well as in non-saline sandy loam soils located in Parlier, California. Phospholipid fatty acid (PLFA) analysis was used to characterize soil microbial community composition for trees grown at both locations. Microbial biomass was lower in the saline soil compared to non-saline soil in spring 2013. However, in fall 2013 and winter 2014, total biomass, fungi, arbuscular mycorrhizal fungi (AMF), actinomycetes, Gram + bacteria and Gram – bacteria at saline sites remained similar or higher than non-saline sites. The increase in the deposition of organic matter from the poplar trees at both locations likely contributed to the soil microbial community structure and biomass, irrespective of salinity, boron and selenium levels. Consequently, poplar trees may be a suitable crop for growing as a remediation tool in such poor quality soils.