Recipient Organization
SOUTH DAKOTA STATE UNIVERSITY
PO BOX 2275A
BROOKINGS,SD 57007
Performing Department
Plant Science
Non Technical Summary
In the northern Great Plains (NGP), farmers have been able to take advantage of higher temperatures and spring rainfall. These changes, when combined with improved genetics, crop insurance, and better equipment contributed to the conversion of 728,000 ha of South Dakota grassland to cropland between 2006 and 2012. Climate and land-use changes, when combined with high sodium concentrations in one of the regions parent materials (marine sediments), have increased the salinization and sodification risks. High sodium concentrations causes soil aggregates and structure to break down. When this occurs, the permeability of soil to water is reduced. Under these conditions tile lines can fail to remove water, resulting in water ponding and large yield losses. In the northern Great Plains, salts transported from the marine sediments to upper soil horizons causes surface soil structure destabilization within several years. Climate changes have exacerbated this risk. NGP grain productivity losses threaten local, regional, and global food security. Our goal is to develop and test the ability of different management practices to reduce this risk.Field and laboratory research will be conducted that is designed to mitigate this problem. Traditional remediation techniques such as tile drainage, applying gypsum, and application of low EC water will be compared with reseeding with perennial plants. Changes in soil and plant health will be quantified. The findings will be used to create a model that can be used to assess the impact of remediation on soil health. The model will be made available to soil testing laboratories and professional agronomists. Findings will be published technical journals and presented in scientific conferences.
Animal Health Component
70%
Research Effort Categories
Basic
30%
Applied
70%
Developmental
(N/A)
Goals / Objectives
The expanding Northern Great Plains (NGP) soil salinity and sodicity problems result from increasing rainfall, which elevates the risk of capillary movement of sodium and other salts from underlying marine sediments to the soil surface. This situation has placed many otherwise highly productive soils at the tipping point of sustainability. Disturbingly, following traditional saline remediation strategies of installing tile drainage, applying gypsum, and leaching with "good" quality water exacerbate this problem. The objectives are to: 1) determine the change in ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from traditional saline/sodic soil remediation to an innovative vegetative remediation strategy; and 2) create decision support tools that provide options to restore ecosystem services on salt-affected lands.
Project Methods
Objective 1. Determine the change in ecosystem services (GHG emissions, pollinator habitat, nutrient cycling, and carbon sequestration) associated with switching from traditional saline/sodic soil remediation to an innovative vegetative remediation strategyIn years 1 through 4, manipulative replicated field experiments will be conducted to evaluate remediation and restoration methods. No-tillage or conservation tillage will be used at all sites. The research will be conducted at representative sites. In South Dakota research will be conducted in higher (summit/shoulder) and lower (footslope) elevational positions.The experimental design will be a split plot. A range of experiments will be used. One type of experiment will be to compare changes in EC and Na over time. In other experiments, we will determine the impact of chemical or biological treatments on restoration. Where feasible, the experiment will be placed over a previously installed drainage system. All treatments will be replicated at least 3 times and the individual plot size will be at least 20 by 50 m.Treatments will be dictated by the site. For example, elemental S and gypsum application rates will be based on the soil SAR values. In grassland and cropland treatments, appropriate salt tolerant cover crops mixtures will be seeded after corn's weed free period. Unpublished research suggests that in-season cover crops can help corn to overcome some of the adverse soil conditions in the Na affected soils. Other information that will be considered for treatment identification will include soil organic C, Landsat images of previous problems, and evidence of extensive erosion. Ecosystem function and resulting services will be measured.The findings will be statistically analyzed and published in technical journal. Based on these materials, versions suitable for undergraduate and graduate student classroom will be prepared. The effectiveness of the materials will be assessed using pre and post testing.The milestones are selecting the research sites, placing the treatments, collecting the soil and plant samples, writing the technical papers and educational materials. The impacts of the papers will be assessed by counting read, downloads, and citations.Objective 2. Create decision support tools that provide options to restore ecosystem services on salt-affected lands.Based on field results described above, models that assess the effect of the restoration treatments on recovery will be developed. These models will be validated with data collected experiments not used to develop the models