Progress 05/01/18 to 04/30/23
Outputs
Target Audience:The target audience includes scientists, students, farmers, and agricultural specialists. Changes/Problems:A major change in our activities is to include the development of a book designed for undergraduate students and agricultural professionals. The focus of the book is to provide scientific answers to difficult problems. The book is almost complete. What opportunities for training and professional development has the project provided?During the past year, 1 PhD student completed (Shaina Westfoff) conducted research on this topic. They received one-on-one training with a mentor, as well as regular meetings with the project team. For professional development they were involved in a salinity study group and producer workshop. Shaina has graduated and accepted a job at SDSU. How have the results been disseminated to communities of interest?During the past year, we were involved in a summit organized by SDSU. The goal of the summit was to identify future goals. The summit was attended by NRCS, SDSU, producers, and non-profit organizations. Findings from the summit are below. South Dakota Soil Salinity Summit Crossroads Hotel and Huron Event Center Huron, SD 1-5 pm, Wednesday May 31, 2023 Breakout Session Summary Awareness Websoil survey salinity risk index (13) Quantification/mapping of areas using past satellite imagery over time (9) Intended audiences (2) Ag community - producers, consultants, businesses (1) Conservationist (2) Consumers/ and those who value certified soil health practices Absentee landowners People valuing land (1) People renting land (5) Policy makers (3) Ag lenders/insurance (7) Youth (1) College courses like PS 213 (1) Broad training/awareness to students of other majors (2) K12 curricula Common messaging (13) Risks or costs to taxpays Correct solutions for the specific soil or farm field Social media - Facebook ads (3) Management plays a role in the problem Long-term permanent solutions - grass - beef - wildlife (5) Precision insurance (9) Problem with solutions (4) Data gathering companies to help us look at the big picture Actions Salinity rating for small grains like wheat, rye, etc. (5) Forage value on salty soil differences between crops like barley vs others Crop rotation information for salty soils Corn hybrid differences; because growers have the ability to change on the go Something done to get small grains back in the rotation (1) Federal farm policy changes; commodity groups are the influencer; stop rewarding producers for doing the wrong things and reward for the good things (13) Removing marginal lands from crop production incentivize on crop insurance premium (2) NO2 emissions reductions on marginal lands (1) NRCS guidelines for saline/sodic soils need changing (10) Expand and improve CSP; make it easier to get in. Continue the practice on the same acre (1) Reduce CSP practice changes for producers; get good at practice on the same acre Create salinity risk index map and incorporate into websoil survey (5) Get info to landowners and producers (1) Bankers and land managers; include these groups in discussions and educational events (4) Fed payment for planting grass FSA/NRCS/RMA integrated programs (11) List of good practices and needed for certain soils where they work the best maybe by MLRA (1) Weather Ready Farms Certification; compliment USDA programs (2) Saline/sodic Soil Center of Excellence; include neighboring northern Great Plains States (12) Training with consistent messages integrated outreach efforts (1) Integrated data sharing between NRCS/FSA and MRA to integrate programs Awareness of issue needs to get out more - audiences (7) CSP enhancement for EAC 3rd party help to improve confidentiality (1) Develop more RCPP saline/sodic soil focus (11) Creating industries for small grains; use of other crops; create markets (10) Barriers RMA - reinsurers (8 companies) (10) Bankers (2) Generational transfer (6) Lack of good information; soil classification; programs (5) Integrated programs; technical information Renter- non operating landowners (7) Local agronomist; product sales (4) In state salinity/sodicity guidelines (6) Operational diversity Practice rates (NRCS practices (4) Lack of program and technical option training with FO staff (2) Institutional limitations (2) Fiscal year funding flexibility; time support Equipment and livestock limitations Social pressure (6) NRCS Practice Standard (610) (7) Program restrictions Time to implement change (3) Higher annual payment rate with EAC (3) NRCS - lack of technical support; lack of technical knowledge lack of relationships with growers (10) Lack of technical flexibility with practice implementation and timing Be open minded to change (5) Opportunities and needs Consistent messaging between interest groups (2) Leveraging outreach efforts (5) Wildlife habitat (5) Water quality improvement Soil health improvement Recreation Diverse income sources Weather/climate resilience (3) Environmental services (3) Industry buy-in (3) Land ethic (3) Crop insurance incentives (7) Unified messaging: programs and money (6) Mold programs to fit need (1) Reduce risk of adopting practices (2) Holistic approach to management (1) Animal infrastructure Markets - local and national infrastructure; especially small grains; industry buy-in (4) Producer stories, outreach (5) Ag lender engagement (9) Crop insurance change (9) Updated soils information/data (12) Plant breeding Livestock (1) Crop rotations (1) Policy; crop insurance; CRP rental rate reversal (pay better for poorer soils) (2) Funding/money Risk analyses (7) Stop new breaking (2) Absentee landowner education NRCS Standard updates (4) Crop insurance: better livestock incentive Landowner cooperation Farmer/producer/landowner groups to develop policy/programs Specialty market groups: work with those already established What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Objective 1. (95% Accomplished) Greenhouse gas emissions Although salinity and sodicity are global problems, information on greenhouse gas emissions from agricultural salt-affected soils is scarce. CO2-C and N2O-N emissions were quantified from three zones intertwined within a single Northern Great Plains USA field: 1) a highly productive zone (EC 1:1 = 0.4 dS m-1; SAR= 1.8), 2) a transition zone (moderately salt-affected) (EC1:1=1.6 dS m-1; SAR = 4.99), and 3) a saline/sodic zone (EC1:1 = 3.9 dS m-1; SAR = 22). In each zone, emissions were measured every 4 h for 7 days in 4 randomly placed chambers that were treated with 2 N rates (0 and 224 kg N ha-1). The experiment was conducted in 2018 and 2019 during similar seasonal periods. Soil samples taken from treatments after GHG measurement were analyzed for soil inorganic N, and microbial biomass from different communities was quantified using phospholipid fatty acid analysis (PFLA). Real-time PCR was used to quantify the number of copies of some specific denitrification functional genes. The productive zone had the highest CO2-C and lowest N2O-N emissions, and the greatest microbial biomass, whereas the saline/sodic zone had the lowest CO2-C and highest N2O-N emissions, and the lowest microbial biomass. Within a zone, urea application did not influence CO2-C emissions, however, N2O-N emissions from the urea-treated saline/sodic zone were 84 and 57% higher than the urea-treated productive zone in 2018 and 2019, respectively. The copy number of the nitrite reductase gene, nirS, was 42-fold higher in the saline/sodic than the productive soil, suggesting that the saline/sodic soil had a high potential for denitrification. These findings suggest N2O-N emissions could be reduced by not applying N to saline/sodic zones. Drainage Increased rainfall is increasing the risk of the capillary movement of sodium and other salts from buried marine sediments to the soil surface in the North America's northern Great Plains. These salts reduce productivity and resilience, while adversely affecting the environment. Understanding the interactions among management, climate, cropping system, and soil is the first step toward implementing effective management plans. This study determined the influence of soil depth on hydraulic conductivity and changes in soil Na+ (mg Na+/kg soil) to EC1:1 (dS/m) ratio following high spring rainfall in 2019 in three soils. The landscape positions included in the study were a well-drained shoulder, moderately well drained backslope, and a poorly drained toeslope soil. Based on the soil classification, shoulder and backslope subsoils were not predicted to be salt affected, while the toe-slope soil was predicted to contain a natric soil horizon. Rainfall in 2018, 2019, and 2020 was 46, 76, and 37 cm, respectively, and soil cores were collected prior to and following the 2019 high rainfall. Samples from 2018 were analyzed for soil electrical conductivity (EC1;1), pH, ammonium acetate extractable cations, soil particle size, available water at field capacity, drainable porosity, soil bulk density, and saturated hydraulic conductivity. Samples from 2019 were analyzed for EC1:1 and ammonium acetate extractable Na+. Across the sampling sites, shoulder and backslope soils had higher saturated hydraulic conductivities than the toe-slope soils. Saturated hydraulic conductivities were negatively correlated to pH (r=-0.55, p<0.01), the Na+ to EC1;1 ratio (r= -0.66, p<0.01), extractable Na+ (r= -0.56, p<0.01), and sand content (r = -0.66, p<0.01), and positively correlated to the silt content (r=0.65, p<0.01). A comparison between the saturated hydraulic conductivity and the Na+ to EC1:1 ratio suggests that saturated conductivities approached 0 cm h-1 when the Na+ to EC1:1 ratio exceeded 600 (mg Na/kg)(dS/m)-1. The high rainfall in 2019 increased the risk of soil dispersion in the lower soil depths (>82.5 cm). For example, in the shoulder soil at the 105- to 112.5 cm depth, EC1:1 decreased 0.936 ± 0.254 dS/m from 2018 to 2019, whereas the exchangeable Na+ increased 688 ±283 mg/kg soil. Our findings suggest that a climate change-induced shift in rainfall patterns can increase salinity and socidicy risks in northern Great Plains subsurface soils. Salinity and sodicity risks are expanding into zones not previously identified as at risk, and improving the productivity of these soils requires careful planning. Reseeding with perennial plants 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. Phytoremediation treatments included corn (Zea mays) and 2 perennial grass mixes that were planted and compared with a no-plant control treatment across three soil zones. Perennial grasses were dormant seeded in the 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 years (2018, 2019, and 2020) total corn biomass in the saline sodic soil was 2794 ±2012 kg/ha, whereas perennial grass yields were 4733 ±1385 kg/ha. In the good soil, total corn biomass produced was 7927 ±2353, whereas the perennial grass production was 6454 ±1566. Across soil zones, total corn biomass was 5,990, 3,900, and 6,150 kg ha-1 in 2018, 2019, and 2020, respectively, whereas perennial grass biomass yields averaged 1,220, 9,065, and 7,375 kg ha-1 in 2018, 2019, and 2020, respectively. In 2019, the depth to the water table EC1:1 (-0.83 ±0.149 dS/m) and exchangeable Na+ (-656 ±220) decreased in all treatments. With drier conditions from the fall of 2019 through the spring 2021, the depth to groundwater increased, the EC1:1 decreased in the transition soil but increased in the saline/sodic soil (p=0.001). In conclusion, this and related work showed that phytoremediation, when combined with high natural rainfall, reduced soil EC1;1 and the exchangeable Na+ in all soils, however these benefits may be short lived and as the water tables dropped in 2020, EC1:1 increased in the saline/sodic zones. Growing plants reduced the risk of soil dispersion and erosion, and improved soil health. Thus, producers should consider planting saline/sodic soils with perennial salt tolerant plants. Objective 2.(95% Accomplished) The data has been collected and we are in the process of developing and using AI techniques to identify problem soils. To date we have learned that the traditional treatment of applying chemical amendments such as gypsum are ineffective. In addition, tile drainage is often not effective in northern Great Plains saline/sodic soils, and dispersed saline sodic soils have GHG emissions that are orders of magnitude higher than surrounding soils. The work also showed that high rainfall only provides a temporary respite from high salt concentrations, reseeding saline sodic with perennial plants may require several years. Objective 3. (95% Accomplished) In 2018, 2019, and 2021 we organized workshops that were attended by over 150 farmers and/or their advisors. Several presentations were given at the SD Professional Soil Scientist meetings and the SD NRCS Technical Planning workshop. Our original intent was to revise our current salinity/sodicity recommendation guides. However, over the last year we decided that a better approach was to combine a revision with a new text book. Our hope is to complete the book in 2022-2023.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Westhoff, S.., Reese, C., and Clay D.E. (2023) Soil Salinity Basics, SD Soil Salinity Summit, Huron SD May 31, 2023.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Westhoff, S., C.L. Reese, D.R. Joshi, J. Miller, G. Reicks, and D.E. Clay. 2022, Traditional soil amendments on aggregate stability in saline/sodic soil in the US Northern Great Plains. ASA 2022 annual meeting, Baltimore. November 7-11.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2023
Citation:
Westhoff. S., C.L. Reese, S.A. Clay, and D.E. Clay. 2021. Efficiency of traditional soil amendments on reclaiming salt affect acres in the northern Great Plains. ASA-CSSA-SSSA International Annual Meeting. Nov. 9-13 Salt Lake City
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Clay, D.E., S.A. Clay, C. Reese, S. Westhoff, J. Miller, G. Reicks, and D. Joshi. 2021. Perennial grass effect on salinity and sodicity. NRCS Annual CIG Showcase. April 2021, Zoom presentation.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Clay, D.E., S.A. Clay, C. Reese, S. Westhoff, J. Miller, G. Reicks, and D. Joshi. 2021. Perennial grass effect on salinity and sodicity. SD CSS Technical Planning Workshop. April 7, 2021, Zoom presentation.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Clay, D.E. 2019. Using soil test results to assess salinity and sodicity risks. Soil Salinity Workshop, June 2019, Attendance 50.
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Clay, S.A, Fiedler, D., C.L. Reese, and Clay D.E. (2022), Restoring ecological function to South Dakota saline/sodic soils with perennial grass mixtures. Agronomy Journal 2022, 1-12.
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Fiedler, D.E., Clay, S.A., Westhoff, S., Reese, C.L., Bruggeman, S.A., Moriles-Miller-, J. Perkins, L., Joshi, D.R., Marzano, S.Y. and Clay. D.E. (2022) Phytoremediation and rainfall combine to improve soil and plant health in a North America Northern Great Plains saline sodic soil. Journal of Soil Water and Conservation 77, 1-8.
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Budak, M.E., D.E. Clay, S.A. Clay, C.L. Reese, S. Westhoff, L.E. Howe, R.K. Owens, G. Birru, Y. He, and Z. Wang. 2022. Increased rainfall may place saline/sodic soils on the tipping point of sustainability. Soil Water Conservation 77:418-425.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Fiedler, D.J., D.E. Clay, D.R. Joshi. A. Engel, S.Y. Marzano., D. Jakubowski, D. Bhattarai. C.L. Reese. S.A. Bruggeman, and S.A. Clay. 2021. CO2 and N2O emissions and microbial community structure from fields that include salt effects soils. J. Environ., Qual. https://doi.org/10.1002/jeq2.20223
|
Progress 05/01/21 to 04/30/22
Outputs
Target Audience:The target audience includes scientists, students, farmers, and agricultural specialists. Changes/Problems:A major change in our activities is to include the development of a book designed for undergraduate students and agricultural professionals. The focus of the book is to provide scientific answers to difficult problems. What opportunities for training and professional development has the project provided?During the past year, 5 MS students in Agronomy (Achnal Neupane, Sam Thies, Andrew Engle, Abigail Pranchard, and Doug Fiedler) conducted research on this topic. They received one-on-one training with a mentor, as well as regular meetings with the project team. For professional development they were involved in a salinity study group and producer workshop. Several of these students have graduated (Sam Thies, Doug Fiedler, Abigail Pranchard) and are working in industry or NRCS. How have the results been disseminated to communities of interest?During the last year we held a workshop that was attended by approximately 50 farmers. In addition, topics have been routinely presented to our soil health work group, in classes, and webinars. Over the last year we made several presentations to the NRCS technical committee meeting. We had several meetings with a group of authors about writing a new salinity/sodicity textbook. This book was approved by the ASA/CSA/SSSA book committee and we are busy writing chapters. The book is in progress and a number of draft chapters have been prepared. What do you plan to do during the next reporting period to accomplish the goals?Objective 1. Determine the ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from the traditional saline/sodic soil remediation (soil amendments and drainage) approach to vegetative remediation. Based on this research we will prepare and submit articles to scientific journals. Over the next year, these papers will be published and converted into chapters in a text book. Objective 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands. Preliminary data suggests that problem areas may be linked to several criteria including low laying areas, shallow alluvial and glacial deposits, and soils with 50-70% sand. These results need to be tested at other sites. We have identified many problem zones. Over the next years these will be used to create chapters for a new text book Objective 3. Distribute project findings and analytics to end-users. When the book is completed they will be distributed to end-users world wide
Impacts
What was accomplished under these goals?
Objective 1. (90% Accomplished) Greenhouse gas emissions Although salinity and sodicity are global problems, information on greenhouse gas emissions from agricultural salt-affected soils is scarce. CO2-C and N2O-N emissions were quantified from three zones intertwined within a single Northern Great Plains USA field: 1) a highly productive zone (EC 1:1 = 0.4 dS m-1; SAR= 1.8), 2) a transition zone (moderately salt-affected) (EC1:1=1.6 dS m-1; SAR = 4.99), and 3) a saline/sodic zone (EC1:1 = 3.9 dS m-1; SAR = 22). In each zone, emissions were measured every 4 h for 7 days in 4 randomly placed chambers that were treated with 2 N rates (0 and 224 kg N ha-1). The experiment was conducted in 2018 and 2019 during similar seasonal periods. Soil samples taken from treatments after GHG measurement were analyzed for soil inorganic N, and microbial biomass from different communities was quantified using phospholipid fatty acid analysis (PFLA). Real-time PCR was used to quantify the number of copies of some specific denitrification functional genes. The productive zone had the highest CO2-C and lowest N2O-N emissions, and the greatest microbial biomass, whereas the saline/sodic zone had the lowest CO2-C and highest N2O-N emissions, and the lowest microbial biomass. Within a zone, urea application did not influence CO2-C emissions, however, N2O-N emissions from the urea-treated saline/sodic zone were 84 and 57% higher than the urea-treated productive zone in 2018 and 2019, respectively. The copy number of the nitrite reductase gene, nirS, was 42-fold higher in the saline/sodic than the productive soil, suggesting that the saline/sodic soil had a high potential for denitrification. These findings suggest N2O-N emissions could be reduced by not applying N to saline/sodic zones. Drainage Increased rainfall is increasing the risk of the capillary movement of sodium and other salts from buried marine sediments to the soil surface in the North America's northern Great Plains. These salts reduce productivity and resilience, while adversely affecting the environment. Understanding the interactions among management, climate, cropping system, and soil is the first step toward implementing effective management plans. This study determined the influence of soil depth on hydraulic conductivity and changes in soil Na+ (mg Na+/kg soil) to EC1:1 (dS/m) ratio following high spring rainfall in 2019 in three soils. The landscape positions included in the study were a well-drained shoulder, moderately well drained backslope, and a poorly drained toeslope soil. Based on the soil classification, shoulder and backslope subsoils were not predicted to be salt affected, while the toe-slope soil was predicted to contain a natric soil horizon. Rainfall in 2018, 2019, and 2020 was 46, 76, and 37 cm, respectively, and soil cores were collected prior to and following the 2019 high rainfall. Samples from 2018 were analyzed for soil electrical conductivity (EC1;1), pH, ammonium acetate extractable cations, soil particle size, available water at field capacity, drainable porosity, soil bulk density, and saturated hydraulic conductivity. Samples from 2019 were analyzed for EC1:1 and ammonium acetate extractable Na+. Across the sampling sites, shoulder and backslope soils had higher saturated hydraulic conductivities than the toe-slope soils. Saturated hydraulic conductivities were negatively correlated to pH (r=-0.55, p<0.01), the Na+ to EC1;1 ratio (r= -0.66, p<0.01), extractable Na+ (r= -0.56, p<0.01), and sand content (r = -0.66, p<0.01), and positively correlated to the silt content (r=0.65, p<0.01). A comparison between the saturated hydraulic conductivity and the Na+ to EC1:1 ratio suggests that saturated conductivities approached 0 cm h-1 when the Na+ to EC1:1 ratio exceeded 600 (mg Na/kg)(dS/m)-1. The high rainfall in 2019 increased the risk of soil dispersion in the lower soil depths (>82.5 cm). For example, in the shoulder soil at the 105- to 112.5 cm depth, EC1:1 decreased 0.936 ± 0.254 dS/m from 2018 to 2019, whereas the exchangeable Na+ increased 688 ±283 mg/kg soil. Our findings suggest that a climate change-induced shift in rainfall patterns can increase salinity and socidicy risks in northern Great Plains subsurface soils. Salinity and sodicity risks are expanding into zones not previously identified as at risk, and improving the productivity of these soils requires careful planning. Reseeding with perennial plants 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. Phytoremediation treatments included corn (Zea mays) and 2 perennial grass mixes that were planted and compared with a no-plant control treatment across three soil zones. Perennial grasses were dormant seeded in the 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 years (2018, 2019, and 2020) total corn biomass in the saline sodic soil was 2794 ±2012 kg/ha, whereas perennial grass yields were 4733 ±1385 kg/ha. In the good soil, total corn biomass produced was 7927 ±2353, whereas the perennial grass production was 6454 ±1566. Across soil zones, total corn biomass was 5,990, 3,900, and 6,150 kg ha-1 in 2018, 2019, and 2020, respectively, whereas perennial grass biomass yields averaged 1,220, 9,065, and 7,375 kg ha-1 in 2018, 2019, and 2020, respectively. In 2019, the depth to the water table EC1:1 (-0.83 ±0.149 dS/m) and exchangeable Na+ (-656 ±220) decreased in all treatments. With drier conditions from the fall of 2019 through the spring 2021, the depth to groundwater increased, the EC1:1 decreased in the transition soil but increased in the saline/sodic soil (p=0.001). In conclusion, this and related work showed that phytoremediation, when combined with high natural rainfall, reduced soil EC1;1 and the exchangeable Na+ in all soils, however these benefits may be short lived and as the water tables dropped in 2020, EC1:1 increased in the saline/sodic zones. Growing plants reduced the risk of soil dispersion and erosion, and improved soil health. Thus, producers should consider planting saline/sodic soils with perennial salt tolerant plants. Objective 2. (75% Accomplished) The data has been collected and we are in the process of developing and using AI techniques to identify problem soils. To date we have learned that the traditional treatment of applying chemical amendments such as gypsum are ineffective. In addition, tile drainage is often not effective in northern Great Plains saline/sodic soils, and dispersed saline sodic soils have GHG emissions that are orders of magnitude higher than surrounding soils. The work also showed that high rainfall only provides a temporary respite from high salt concentrations, reseeding saline sodic with perennial plants may require several years. Objective 3. (75% Accomplished) In 2018, 2019, and 2021 we organized workshops that were attended by over 150 farmers and/or their advisors. Several presentations were given at the SD Professional Soil Scientist meetings and the SD NRCS Technical Planning workshop. Our original intent was to revise our current salinity/sodicity recommendation guides. However, over the last year we decided that a better approach was to combine a revision with a new text book. Our hope is to complete the book in 2022-2023.
Publications
- Type:
Journal Articles
Status:
Other
Year Published:
2022
Citation:
Fiedler, D.J., S.A. Clay, D. Joshi, S. Westhoff, C.L. Reese, S.L. Bruggeman, J. Moriles-Miller-, L.B. Perkins, D.R. Joshi, S.Y. Marzano, and D.E. Clay. 2022. Phytoremediation and rainfall combine to improve soil and plant health in a North America Northern Great Plains saline sodic soil. J. Soil Water Conservation (in press).
- Type:
Journal Articles
Status:
Other
Year Published:
2022
Citation:
Budak, M.E., D.E. Clay, S.A. Clay, C.L. Reese, S. Westhoff, R.K. Owens, G. Birru, Z. Wang, and Y. He. 2022. Increased rainfall may place saline/sodic soils on the tipping point of sustainability. Soil Water Conservation (in press).
- Type:
Journal Articles
Status:
Other
Year Published:
2021
Citation:
Fiedler, D.J., D.E. Clay, D.R. Joshi, A. Engle, S.Y. Marzano, D. Jsakuboewski, D. Bhattarai, C. L. Reese, S. S.A. Bruggeman, and S.A. Clay. 2021. CO2 and N2O emissions and microbial community structure from fields that include salt-affected soils. Journal of Environmental Quality. (in press)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Clay, D.E., S.A. Clay, C. Reese, S. Westhoff, J. Miller, G. Reicks, and D. Joshi. 2021. Perennial grass effect on salinity and sodicity. SD CSS Technical Planning Workshop. April 7. (Virtual).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Reese, C.L., C. Scaunaman, B. Ostrum, and L. Howe. 2020. Managing salinity. Dirt Dakota: innovation, research, and technology workshop. December 8-9. Available at https://www.ndsu.edu/soilhealth/dirt-workshop/
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Clay, D.E., S.A. Clay, C. Reese, S. Westhoff, J. Miller, G. Reicks, and D. Joshi. 2021. Perennial grass effect on salinity and sodicity. NRCS Annual CIG Showcase. April 7, 2021. Zoom presentation
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Clay, D.E., S.A. Clay, C. Reese, S. Westhoff, J. Miller, G. Reicks, and D. Joshi. 2021. Perennial grass effect on salinity and sodicity. SD CSS Technical Planning Workshop. April 7. Zoom presentation.
|
Progress 05/01/20 to 04/30/21
Outputs
Target Audience:The target audience includes scientists, students, farmers, and agricultural specialists. Changes/Problems:In 2018 and 2019, flooding slowed field work, and in 2020 COVID-19 slowed laboratory work and our ability to communicate findings to end users. What opportunities for training and professional development has the project provided?During the past year, 5 MS students (Achnal Neupane, Sam Thies, Andrew Engle, Abigail Pranchard, and Doug Fiedler) conducted research on this topic. They received one-on-one training with a mentor, as well as regular meetings with the project team. For professional development they were involved in a salinity study group and producer workshop. Several of these students have (Sam Thies and Doug Fiedler) or will be graduating during spring and summer of 2021 (Abigail Pranchard) How have the results been disseminated to communities of interest?During the last year we held a workshop that was attended by approximately 50 farmers. In addition, topics have been routinely presented to our soil health work group. Over the last year we made several presentations to the NRCS technical committee meeting. Due to COVID-19 a planned workshop was cancelled. We had several meetings with a group of authors about writing a new salinity/sodicity textbook. This book was approved by the ASA/CSA/SSSA book committee and we are busy writing chapters. What do you plan to do during the next reporting period to accomplish the goals?Goal 1. Determine the ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from the traditional saline/sodic soil remediation (soil amendments and drainage) approach to vegetative remediation. Based on this research we will prepare and submit articles to scientific journals. Goal 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands. Preliminary data suggests that problem areas may be linked to several criteria including low laying areas, shallow alluvial and glacial deposits, and soils with 50-70% sand. These results need to be tested at other sites. Goal 3. Distribute project findings and analytics to end-users. We cancelled the workshop for 2020 and we have plans to reschedule this meeting for 2021.
Impacts
What was accomplished under these goals?
Goal 1. Determine the ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from the traditional saline/sodic soil remediation (soil amendments and drainage) approach to vegetative remediation. (75% Accomplished) We conducted experiments designed to address the problems associated with the growing salinity and sodicity problems in the northern Great Plains. A common restoration treatment for saline-sodic soils involves improving soil drainage, applying soil amendments, and leaching with water that has a relatively low electrical conductivity. However, due to high subsoil bulk densities, low drainable porosities, and high sulfate concentrations these treatments may not be effective in our soils. Greenhouse gas emissions Although salinity and sodicity are global problems, information on greenhouse gas emissions from agricultural salt-affected soils is scarce. CO2-C and N2O-N emissions were quantified from three zones intertwined within a single Northern Great Plains USA field: 1) a highly productive zone (EC 1:1 = 0.4 dS m-1; SAR= 1.8), 2) a transition zone (moderately salt-affected) (EC1:1=1.6 dS m-1; SAR = 4.99), and 3) a saline/sodic zone (EC1:1 = 3.9 dS m-1; SAR = 22). In each zone, emissions were measured every 4 h for 7 days in 4 randomly placed chambers that were treated with 2 N rates (0 and 224 kg N ha-1). The experiment was conducted in 2018 and 2019 during similar seasonal periods. Soil samples taken from treatments after GHG measurement were analyzed for soil inorganic N, and microbial biomass from different communities was quantified using phospholipid fatty acid analysis (PFLA). Real-time PCR was used to quantify the number of copies of some specific denitrification functional genes. The productive zone had the highest CO2-C and lowest N2O-N emissions, and the greatest microbial biomass, whereas the saline/sodic zone had the lowest CO2-C and highest N2O-N emissions, and the lowest microbial biomass. Within a zone, urea application did not influence CO2-C emissions, however, N2O-N emissions from the urea-treated saline/sodic zone were 84 and 57% higher than the urea-treated productive zone in 2018 and 2019, respectively. The copy number of the nitrite reductase gene, nirS, was 42-fold higher in the saline/sodic than the productive soil, suggesting that the saline/sodic soil had a high potential for denitrification. These findings suggest N2O-N emissions could be reduced by not applying N to saline/sodic zones. Drainage The purpose of this study was to assess why drainage does not work in some soils. The model system was located in the US northern Great Plains. The objective was to determine temporal physical and chemical changes in soils collected from three landscape positions. Tile drainage was installed in 2016 and four undisturbed soil cores (7.5 cm x 120 cm) were collected from 3 landscape positions in 2018 and 2019. Soil samples in 2018 and 2019 (from 0-7.5 cm, 50-57.5 cm, 82.5-90 cm, 92.5-100 cm, and 105-112.5 cm depths) and were analyzed for soil ECe, pH, and Na+ concentration, whereas samples from 2019 were analyzed for soil particle size, available water at field capacity, drainable porosity, soil bulk density, and saturated hydraulic conductivity. From 2018 to 2019 there was a decrease for the ECe and Na+ in the surface soil. However, this decrease was associated with an increased in the Na to ECe ratio, suggesting an increased risk of dispersion. These findings suggest that the increased soil dispersion risks could reduce the subsurface drainage efficiency. Moreover, other physical properties that are responsible for the effectiveness of tile drainage could be harmed. High bulk densities, low drainable porosities, and low saturated hydraulic conductivities will reduce the effectiveness of subsurface drainage were associated with back and toe slope soils. These results might be attributed to the low saturated hydraulic conductivity rates, low drainable porosity, and high bulk density in the subsurface soil depths. Our findings suggest that subsurface drainage is not recommended to remove the excess sodium and other salts for these soils. Reseeding with perennial plants In areas of the US northern Great plains where marine sediments are close to the soil surface, the transport of sodium and other salts to the soil surface through capillary action can destabilize the soil structure, increase greenhouse gas emissions, and reduce plant productivity. Understanding the relationship between plant productivity and salt accumulation is needed to reduce these risks. The objective was to determine if reseeding degraded saline/sodic soils to perennial plants could reduce salt accumulation while increasing biomass production. A three-year study (2018, 2019, and 2020) replicated study determined the effects of 4 plant compositions (two perennial plant mixtures, corn, and none) in low, medium, and high saline/sodic soils on temporal changes in the soil EC1:1, Na, Na/EC1:1, and plant productivity. Rainfall in 2018, 2019, and 2020 were 421, 770, and 373 mm. In the high saline/sodic area, during the year of plant establishment (2018), both perennial grass mixtures produced little biomass (2000 kg ha-1), whereas in the second year, both grass mixtures produced more biomass (>880 kg ha-1) than corn (< 4000 kg ha-1). In 2020, the perennial grass mixtures and corn produced amounts of biomass (6300 kg ha-1). This research will be continued in 2021. Microbial diversity Saline soil is detrimental to the growth of many different species of plants; however, some species are able to grow. The microbiome within the roots of a plant and in the rhizospheric soil play a crucial role in the growth of the plant. When comparing the root microbiome of saline soil and good soil, it is important to understand the difference between these two. We hypothesized that root-associated microbiomes from saline-sodic soil are dissimilar to those from normal good soil, regardless of plant species. Our research showed that samples gathered from saline-sodic and non-salt effected areas had different microbial community structures and clustering. The alpha and beta diversity of the samples were different, as well as the identified taxa within the samples for bacterial and fungal populations. In summary, saline-sodic condition allows for an enrichment of three bacterial species, including Azoarcus, an uncultured forest bacterium, and a Pelagicoccus, and reduced the abundance of two species of an acidibacter and an uncultured bacteria belonging to Roseilexaceae family, regardless of the plant host species. Moreover, fungal population in the Xylariales, Septophoma, and Ceratobasidium taxa were reduced significantly under saline-sodic condition. Goal 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands. (50% Accomplished) At this point we are collecting data that will be used to develop modeling tools. Preliminary analysis suggests that sand content is an important value to measure. Goal 3. Distribute project findings and analytics to end-users. (75% Accomplished) In 2018 and 2019 we organized two workshops that were attended by over 100 farmers and/or their advisors. The workshop for 2020 was cancelled due to COVID-19. In addition, several presentations were given at the SD Professional Soil Scientist meeting and the SD NRCS Technical Planning workshop.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2021
Citation:
Fiedler, D.J., D.E. Clay, D.R. Joshi, A. Engle, S.Y. Marzano, D. Jsakuboewski, D. Bhattarai, C. L. Reese, S. S.A. Bruggeman, and S.A. Clay. 2021. CO2 and N2O emissions and microbial community structure from fields that include salt-affected soils. Journal of Environmental Quality. (in press)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Clay, D.E., S.A. Clay, C. Reese, S. Westhoff, J. Miller, G. Reicks, and D. Joshi. 2021. Perennial grass effect on salinity and sodicity. SD CSS Technical Planning Workshop. April 7. (Virtual).
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Reese, C.L., C. Scaunaman, B. Ostrum, and L. Howe. 2020. Managing salinity. Dirt Dakota: innovation, research, and technology workshop. December 8-9. Available at https://www.ndsu.edu/soilhealth/dirt-workshop/
|
Progress 05/01/19 to 04/30/20
Outputs
Target Audience:The target audience includes scientists, students, farmers, and agricultural specialists. During last summer (2019) we held a workshop which attracted 50 people from the agricultural community. The project also shared the research findings with students enrolled in introductory soil science and environmental soil chemistry classes. Over the last year, this project had extensive discussion with SD Pheasants Forever and South Dakota Corn Utilization Council. Based on these discussions a new program led by SD Extension Service call "Every Acre Counts" was created. The State of South Dakota and NRCS have dedicated 1 million dollars each to reseeding impacted soils. We have plans to present findings at a professional meeting in November 2020. Changes/Problems:During the last year significant flooding occurred which slowed field work. Due to flooding, we have increased the laboratory components of the project. What opportunities for training and professional development has the project provided?During the past year, 5 MS students (Achnal Neupane, Sam Thies, Andrew Engle, Abigail Pranchard, and Doug Fiedler) conducted research on this topic. They received one-on-one training with a mentor, as well as regular meetings with the project team. For professional development they were involved in a salinity study group and producer workshop. How have the results been disseminated to communities of interest?During the last year we held a workshop that was attended by approximately 50 farmers. In addition, topics have been routinely presented to our soil health work group. At the last working group, the SD State NRCS Conservationist asked one of the graduate students to present their finding at the upcoming NRCS technical committee meeting. In addition to these meetings, we were involved in an NPR interview with Lori Walsh and a podcast by the American Society of Agronomy. We also had discussions with Pheasants Forever and SD Corn Utilization Council. These meetings were very productive and resulted in these groups providing funding for restoration. They visited with the Governor and a million dollars were identified and match with money provided by NRCS. The goal of this program, called "Every Acre Counts," is to reseed non-productive lands to perennial plants. What do you plan to do during the next reporting period to accomplish the goals?Goal 1. Determine the ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from the traditional saline/sodic soil remediation (soil amendments and drainage) approach to vegetative remediation. Based on this research we will prepare and submit articles to scientific journals. Goal 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands. Preliminary data suggests that problem areas may be linked to several criteria including low laying areas, shallow alluvial and glacial deposits, and soils with 50-70% sand. These results need to be tested at other sites. Goal 3. Distribute project findings and analytics to end-users. We cancelled the workshop for 2020 and we are working to create videos that can be posted online.
Impacts
What was accomplished under these goals?
Goal 1. Determine the ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from the traditional saline/sodic soil remediation (soil amendments and drainage) approach to vegetative remediation. (50% Accomplished) We have conducted experiments designed to address the problems associated with the growing salinity and sodicity problems in the northern Great Plains. A common restoration treatment for saline-sodic soils involves improving soil drainage, applying soil amendments, and leaching with water that has a relatively low electrical conductivity. However, due to high subsoil bulk densities, low drainable porosities, and high sulfate concentrations these treatments may not be effective in our soils. Greenhouse gas emissions Saline/sodic soils that are intertwined and managed like the surrounding highly productive areas may disproportionally emit fertilizer-derived N2O-N into the atmosphere. If this is a possibility, then then the adoption of site-specific N applications may be warranted. However, because costs are often greater than returns, precision management may not be implemented. In this study, CO2-C and N2O-N emissions and microbial community structure were quantified in three soils treated with 2 N rates (0 and 224 kg N ha-1). Emissions were measured every 4 hours for 7 days after urea application from productive (EC = 0.5 dS m-1; SAR= 4), transition (EC=1.4 dS m-1; SAR = 6.8) and saline/sodic (EC = 6.7 dS m-1; SAR = 28) soils. Soil samples were analyzed for soil inorganic N and the microbial community parameters using phospholipid fatty acid analysis (PFLA). Each treatment was duplicated, and the emissions experiment was replicated in 2018 and 2019. The productive soil had the highest CO2-C and the lowest N2O-N emissions, whereas the saline/sodic area had the lowest CO2-C and highest N2O-N emissions and, in 2019, the lowest microbial biomass in all measured categories. In 2019, N2O-N emissions from the urea-treated saline/sodic soil were 77 and 58% higher than the urea-treated productive and transition soils, respectively. These findings indicate that not applying N to nonproductive saline/sodic areas can provide greater reductions in N2O-N emissions than a simple decrease in the N rate would suggest. Drainage The purpose of this study was to assess why drainage does not work in some soils. The model system was located in the North America northern Great Plains. The objective was to determine temporal physical and chemical changes in soils collected from three landscape positions. Tile drainage was installed in 2016 and four undisturbed soil cores (7.5 cm x 120 cm) were collected from 3 landscape positions in 2018 and 2019. Soil samples in 2018 and 2019 (from 0-7.5 cm, 50-57.5 cm, 82.5-90 cm, 92.5-100 cm, and 105-112.5 cm depths) and were analyzed for soil ECe, pH, and Na+ concentration, whereas samples from 2019 were analyzed for soil particle size, available water at field capacity, drainable porosity, soil bulk density, and saturated hydraulic conductivity. From 2018 to 2019 there was a decrease for the ECe and Na+ in the surface soil. However, this decrease was associated with an increased in the Na to ECe ratio, suggesting an increased risk of dispersion. These findings suggest that the increased soil dispersion risks could reduce the subsurface drainage efficiency. Moreover, other physical properties that are responsible for the effectiveness of tile drainage could be harmed. High bulk densities, low drainable porosities, and low saturated hydraulic conductivities will reduce the effectiveness of subsurface drainage were associated with back and toe slope soils. These results might be attributed to the low saturated hydraulic conductivity rates, low drainable porosity, and high bulk density in the subsurface soil depths. Our findings suggest that subsurface drainage is not recommended to remove the excess sodium and other salts for these soils. Reseeding with perennial plants Studies were conducted to determine the impacts of returning saline-sodic areas to perennial plants on pollinator habitat and soil health. This research was conducted at two field sites in Clark County, SD. Two mixtures of species were used: mix 1) slender wheatgrass, strawberry clover, and beardless wildrye, and mix 2) slender wheatgrass, AC saltlander green wheatgrass (Elymus hoffmannii), creeping meadow foxtail (Alopecurus arundinaceus), and western wheatgrass (Pascopyrum smithii). The cover crops were dormant frost seeded in December and January of 2017. A fallow control was included in both sites, as well as corn, which was planted on May 17th, 2018 and May 31st, 2019 as a comparison cropping system. The climate for the 2018 season was relatively normal, with rainfall from May - September of 36.4 cm, which is similar to the 30-year average of 37.2 cm. Cover crop treatments were reseeded in October 2018 to fill in bare areas that did not establish. The climate for 2019 was wetter than normal, with 71.5 cm of precipitation from May through September. In 2018 grass mixtures had minimal biomass production, with a maximum of 1,700 kg ha-1 and 2,600 kg ha-1 in mix 1 and mix 2, respectively. In 2019, biomass increased to 9,700 kg ha-1 and 10,600 kg ha-1 in mix 1 and mix 2, respectively. In some areas with EC > 10 dS/m we have been unsuccessful at remediation. In non-saline and transition zones (0.8-2.5 dS m-1 EC1:1), mix 1 ground cover was comprised of 61-72% slender wheatgrass, whereas in saline plots (3.2-4.1 dS m-1 EC1:1) beardless wildrye and slender wheatgrass each comprised ~50% of ground cover. Mix 2 was mainly composed of AC saltlander (41-52%) and creeping meadow foxtail (31-41%) in non-saline plots (0.6-1.0 dS m-1 EC1:1). In transition and saline plots (2.3-4.5 dS m-1 EC1:1), mix 2 was dominated by AC saltlander (49-84%). Between 2018 and 2019, changes in soil EC and sodium concentrations were similar between treatments. . Microbial diversity Saline soil is detrimental to the growth of many different species of plants; however, some species are able to grow. The microbiome within the roots of a plant and in the rhizospheric soil play a crucial role in the growth of the plant. When comparing the root microbiome of saline soil and good soil, it is important to understand the difference between these two. We hypothesized that root-associated microbiomes from saline-sodic soil are dissimilar to those from normal good soil, regardless of plant species. Our research showed that samples gathered from saline-sodic and non-salt effected areas had different microbial community structures and clustering. The alpha and beta diversity of the samples were different, as well as the identified taxa within the samples for bacterial and fungal populations. In summary, saline-sodic condition allows for an enrichment of three bacterial species, including Azoarcus, an uncultured forest bacterium, and a Pelagicoccus, and reduced the abundance of two species of an acidibacter and an uncultured bacteria belonging to Roseilexaceae family, regardless of the plant host species. Moreover, fungal population in the Xylariales, Septophoma, and Ceratobasidium taxa were reduced significantly under saline-sodic condition. Goal 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands. (50% Accomplished) At this point we are collecting data that will be used to develop modeling tools. Preliminary analysis suggests that sand content is and important value to measure Goal 3. Distribute project findings and analytics to end-users. (75% Accomplished) During the past two years we organized two workshops that were attended by over 100 farmers and/or their advisors. In addition, several presentations were given at the SD Professional Soil Scientist meeting.
Publications
- Type:
Journal Articles
Status:
Submitted
Year Published:
2021
Citation:
Fielder, D.J., D.E. Clay, D.R. Joshi, D. Bhattarai, C.L. Reese, S. Bruggeman, and S.A. Clay. 2021. Greenhouse gas emissions and microbial community structure from fields that include salt effected soils. J. Environ Quality.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2020
Citation:
Fiedler, D.J. 2020. Phytoremediation of saline-sodic soil in east central South Dakota utilizing perennial grass mixtures. MS Thesis. South Dakota State University Brookings, SD.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2020
Citation:
Blanchard, A.P., S.A. Clay, and L. Perkins. 2020. Revegetation of native plants in salt-impacted soil (poster). Society for Range Management Annual Meeting. February 16-20. Denver, CO.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Fiedler, D. J., D. E. Clay, S. A. Bruggeman, C. L. Reese, and S. A. Clay. 2019. Establishing perennial grass mixtures in saline sodic soils and their impacts of greenhouse gas emissions. Professional Soil Scientist Association of South Dakota Annual Meeting. June 7. Huron SD.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2019
Citation:
Fiedler, D., S. Clay, D., Clay, S. Bruggeman, C. Reese, S. Thies, and A. Engel. 2019. Greenhouse gas emissions of a saline soil and non-saline soil under corn and perennial grass cover crop. American Society of Agronomy. Nov. 10-13. San Antonio, TX.
|
Progress 05/01/18 to 04/30/19
Outputs
Target Audience:The target audience includes scientists, students, farmers, and agricultural specialists. During last summer (2019) we held a workshop which attracted 50 people from the agricultural community. The project also shared the research findings with students enrolled in introductory soil science and environmental soil chemistry classes. Over the last year, this project had extensive discussion with SD Pheasants Forever and South Dakota Corn Utilization Council. Based on these discussions a new program led by SD Extension Service call "Every Acre Counts" was created. The State of South Dakota and NRCS have dedicated 1 million dollars each to reseeding impacted soils. We have plans to present findings at a professional meeting in November 2019. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During the past year, 4 MS students (Achnal Neupane, Sam Thies, Andrew Engle, Abigail Pranchard, and Doug Fiedler) conducted research on this topic. They received one-on-one training with a mentor, as well as regular meetings with the project team. For professional development they were involved in a salinity study group and producer workshop. How have the results been disseminated to communities of interest?During the last year we held a workshop that was attended by approximately 50 farmers. In addition, topics have been routinely presented to our soil health work group. At the last working group, the SD State NRCS Conservationists asked the graduate student to present the finding at the upcoming NRCS technical committee meeting. We also had discussions with Pheasants Forever and SD Corn Utilization Council. These meetings were very productive and based on their activities they were sponsors for obtaining money for restoration. They visited with the Governor and a million dollars were found and match with money provided by NRCS. The goal of this program called "Every Acre Counts" are to reseed non-productive lands to perennial plants. What do you plan to do during the next reporting period to accomplish the goals?Goal 1. Determine the ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from the traditional saline/sodic soil remediation (soil amendments and drainage) approach to vegetative remediation. Based on this research, research papers will be prepared and submitted for publication. Goal 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands. Based on objective decision tools will be created. Goal 3. Distribute project findings and analytics to end-users. We are organizing a workshop for 2020 and we will assist graduate students complete their degrees.
Impacts
What was accomplished under these goals?
Goal 1. Determine the ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from the traditional saline/sodic soil remediation (soil amendments and drainage) approach to vegetative remediation. (50% Accomplished) During the past year we conducted field and laboratory experiments designed to address the problems associated with increasing salinity levels in South Dakota soils. This problem is the result of increasing rainfall that resulted in the transport of subsurface salts to the soil surface. A common restoration treatment for saline-sodic soils involves improving soil drainage, applying soil amendments (e.g. CaSO4, CaCl2, or elemental S), and leaching with water that has a relatively low electrical conductivity. However, due to high subsoil bulk densities and low drainable porosities, these treatments were not effective in our glaciated dryland systems. Field and laboratory studies were conducted to determine the impacts of returning these areas to perennial plants on plant growth, microbial composition, temporal changes in electrical conductivity (ECe), greenhouse gas emissions, pollinator habitat and relative sodium content (%Na). This research was conducted at two field sites (designated North and South) in Clark County, SD. The cover crops seeded alone included slender wheatgrass (Elymus trachycaulus), beardless wildrye (Leymus triticoides), and strawberry clover (Trifolium fragiferum). In addition, two mixtures of species were used: mix 1) slender wheatgrass, strawberry clover, and beardless wildrye, and mix 2) slender wheatgrass, AC saltlander green wheatgrass (Elymus hoffmannii), creeping meadow foxtail (Alopecurus arundinaceus), and western wheatgrass (Pascopyrum smithii). The cover crops were dormant frost seeded in December and January of 2017. A fallow control was included in both sites, as well as corn, which was planted on May 17th, 2018 and May 31st, 2019 as a comparison cropping system. The climate for the 2018 season was relatively normal, with rainfall from May - September of 36.4 cm, which is similar to the 30-year average of 37.2 cm. Cover crop treatments were reseeded in October 2018 to fill in bare areas that did not establish. The climate for 2019 was wetter than normal, with 71.5 cm of precipitation from May through September. In 2018 grass mixtures had minimal biomass production, with a maximum of 1,700 kg ha-1 and 2,600 kg ha-1 in mix 1 and mix 2, respectively. In 2019, biomass increased to 9,700 kg ha-1 and 10,600 kg ha-1 in mix 1 and mix 2, respectively. A student is preparing a thesis on this research. Preliminary analysis indicates that restoration problems increase with the soil EC and exchangeable sodium content. In some areas with EC > 10 dS/m we have been unsuccessful at remediation. In non-saline and transition zones (0.8-2.5 dS m-1 EC1:1), mix 1 ground cover was comprised of 61-72% slender wheatgrass, whereas in saline plots (3.2-4.1 dS m-1 EC1:1) beardless wildrye and slender wheatgrass each comprised ~50% of ground cover. Mix 2 was mainly composed of AC saltlander (41-52%) and creeping meadow foxtail (31-41%) in non-saline plots (0.6-1.0 dS m-1 EC1:1). In transition and saline plots (2.3-4.5 dS m-1 EC1:1), mix 2 was dominated by AC saltlander (49-84%). Between 2018 and 2019, changes in soil EC1:1 and sodium concentrations were similar between treatments. This was likely due to increased precipitation in 2019 and the consequential rise of subsoil salts up the soil profile in saturated conditions, masking any differences due to treatments Greenhouse gas emissions were measured in mid-July 2018 and 2019. In 2018, non-fertilized barren saline soils emitted 611 g CO2-C ha-1 hr-1, which was 62% and 66% less CO2-C than mix 1 and corn, respectively. In 2019, the non-fertilized barren saline soils emitted 324 g CO2-C ha-1 hr-1, which was 87% and 82% less CO2-C than mix 1 and corn, respectively. In 2018, fertilized barren saline soils emitted 810 g CO2-C ha-1 hr-1, which was 62% and 68% less CO2-C than mix 1 and corn, respectively. In 2019, fertilized barren saline soils emitted 825 g CO2-C ha-1 hr-1, which and 73% and 74% less than mix 1 and corn, respectively. Urea fertilizer increased carbon dioxide emissions in grass and corn both years, a result of stimulated microbial activity in response to nitrogen. When averaged between the two years, all treatments emitted between 0.13% and 0.19% of added urea nitrogen through N2O-N emissions. In 2019, applying urea fertilizer increased the rate of N2O emissions from 2.985 to 8.96 g N2O-N/(ha h). Planting either a cover crop or corn reduced N2O emissions from 7.38 to 2.29 g N2O-N/(ha h). In soil samples collected from 2018, microbial assessments showed that the saline/sodic soil and non-salt effected soils had different community structures. Principal coordinate analysis of the good and saline/sodic soil showed that the diversity was reduce in the salty soil. In samples collected from the saline/sodic soils, nonpathogenic fungal endophytes were isolated and we are in the process of determining if these organisms can be used as a seed treatment to accelerate plant growth. From kochia, one of the few surviving plants in saline-sodic soil, root endophytes were isolated and classified. Twelve nonpathogenic fungal endophytes were recovered, including several Fusarium species, an Alternaria alternata strain, a Nigrospora sphaerica strain, a Penicillium olsonii strain, a Periconia species, an Aspergillus ocharaceus strain, and an uncultured fungus. Additionally, several root-associated microbes were isolated, including Pseudomonas mendocina, Aeromonas salmonicida, Bacillus cereus, and Enterobacter cloacae." The research showed that revegetation of saline/sodic soils is a slow process, and therefore to increase pollinator habitat, we investigated different techniques to improve plant success. One approach was to determine if naturally occurring plant vegetation (often considered weedy species) found in the saline-sodic soils of South Dakota can be used as nurse crops to alter the soil environment, making conditions more favorable for eventual colonization by desirable plants. Several plant species naturally found in saline-sodic soils were selected and sown in a saline soil in a greenhouse environment. The impact of the species on soil chemical properties and their growth potential was evaluated. Biochar was also used in combination with plant species, as it has been shown to have beneficial impacts on plant growth in separate preliminary studies. Species selected for study included kochia (Kochia scoparia), forage kochia (Kochia prostrata), green foxtail (Setaria viridis), barnyardgrass (Echinochloa crus-galli), yellow woodsorrel (Oxalis stricta), field pennycress (Thlaspi arvense), AC saltlander (Elymus hoffmannii), and barley (Hordeum vulgare). Goal 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands. (0% Accomplished) At this point we are completing experiments and collecting data. Once this data is compiled we will start developing modeling tools. Goal 3. Distribute project findings and analytics to end-users. (50% Accomplished) During the past two year, we organized two workshops that were attended by over 100 farmers and/or their advisors. In addition, several presentation we given at the SD Professional Soil Scientist meeting.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Joshi, D.R., J. Ulrich-Schad, T. Wang, B.H. Dunn, S.A. Bruggeman, and D.E. Clay. 2019. Grassland retention in the North America Midwest following periods of high commodity prices and climate variability. Soil Sci. Soc. Am. J. 83:1290-1298.
|
|