Phytoremediation and high rainfall combine to improve soil and plant health in a North America northern great plains saline sodic soil

Authors: FIEDLER, DOUGLAS - South Dakota State University; CLAY, SHARON - South Dakota State University; JOSHI, DEEPAK - South Dakota State University; WESTHOFF, SHAINA - South Dakota State University; REESE, CHERYL - South Dakota State University; BRUGGEMAN, STEPHANIE - South Dakota State University; MORELIS-MILLER, JANET - South Dakota State University; PERKINS, LORA - South Dakota State University; Marzano, Shin-Yi; CLAY, DAVID - South Dakota State University

Submitted to: Journal of Soil and Water Conservation Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2021
Publication Date: 5/24/2022
Citation: Fiedler, D.J., Clay, S.A., Joshi, D., Westhoff, S., Reese, C., Bruggeman, S., Morelis-Miller, J., Perkins, L.B., Marzano, S.L., Clay, D.E. 2022. Phytoremediation and high rainfall combine to improve soil and plant health in a North America northern great plains saline sodic soil. Journal of Soil and Water Conservation Society. 77(3). Article 00112. https://doi.org/10.2489/jswc.2022.00112.
DOI: https://doi.org/10.2489/jswc.2022.00112

Interpretive Summary: Saline/sodic soils are often remediated by applying gypsum, improving drainage, and irrigating with high quality water. However, these management approaches may not be effective or feasible in dryland soils supersaturated with gypsum. To create a strategy that optimizes restoration, it is important to identify the soil specific dominant process. For example, how important is that the soil contain CaCO3 or that the soil pH decreases? Much of the current literature explores salinity solutions in irrigated dryland soils and to the best of our knowledge there is scant information on how phytoremediation in humid dryland soils. The objective of this study was to investigate the impact of seeding perennial grasses on soil and plant health in landscapes containing barren saline/sodic soils. We found that planting perennial grass plants and not applying N fertilizer to these soils can reduced the impact of agriculture on the environment and provide habitat for wildlife.

Technical Abstract: A field study, conducted between 2017 and 2021, investigated the effect of phytoremediation on soil and plant health in a landscape containing productive, transition, and saline/sodic soils. Four phytoremediation treatments [none, corn, (Zea mays) and 2 perennial grass mixes] were examined. Perennial grasses were dormant seeded in winter 2017 and 2018 and corn was grown in 2018, 2019, and 2020. Soil samples (0- to 15-cm) were collected on 24 July 2018, 23 July 2019, 24 July 2020, and 15 April 2021. Across soil zones, corn production was 5,990, 3,900, and 6,150 kg ha-1 in 2018, 2019, and 2020, respectively, whereas in the perennial grass treatments yields were 1,220, 9,065, and 7,375 kg ha-1 in 2018, 2019, and 2020, respectively. High rainfall occurred between 2018 through summer 2019 and the depth to ground water, EC1:1, and Na decreased in all treatments, with phytoremediation reducing the Na/EC1:1 ratio. Drier conditions started in fall 2019 through spring 2021: 1) with the depth to groundwater increasing, 2) EC1:1 decreased in the productive soil and increased in the saline/sodic soil; and 3) the risk of soil dispersion (Na/EC1:1 ratio) increased in the productive and transition soils and was static or decreased in the saline/sodic soil. Phytoremediation when combined with high natural rainfall reduced soil EC1;1 and Na in all soils, however as the soil dried in the saline/sodic area EC1:1 increased. These findings suggest that northern Great Plains saline/sodic soils are interdispersed in fields containing very productive soil. These saline/sodic soils can have high nitrous oxide emissions (N2O) and can be rapidly eroded. We believe that planting perennial plants and not applying N fertilizer to these soils can reduced the impact of agriculture on the environment and provide habitat for wildlife.