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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Small Grain and Food Crops Quality Research » Research » Research Project #436581

Research Project: Using Native Rhizobia to Improve Salt-Tolerance in Field Pea

Location: Small Grain and Food Crops Quality Research

Project Number: 3060-21650-002-006-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 1, 2019
End Date: Aug 31, 2024

Objectives for the life of the project will be to: (1) Increase the sustainability of field pea production in the Northern Great Plains by creating a more resilient plant-microbiome system resistant to increasing soil salinity; (2) Identify candidate field pea genomes with tolerance to increasing soil salinity; (3) Identify candidate native rhizobia with tolerance to increasing soil salinity; (4) Compare and contrast the efficacy of native rhizobia with commercial inoculants under abiotic stress; and (5) Test the efficacy of different inoculant delivery systems (granular, peat, liquid) from both native rhizobia and commercial inoculants.

The study will progress on two parallel tracks that will eventually converge. In Track 1, we will isolate and identify native rhizobia with potential for better performance under salt (and drought) stress conditions. In the first year of this study, native rhizobia will be gathered across a range of environments from South Dakota, North Dakota and Montana. Samples will be collected from agricultural land, native prairies and mountainous regions. Field peas (FP) will be potted in each soil as a trap crop for the native rhizobia to nodulate. From these nodules, rhizobia will be cultured and isolated. Preliminary identification based on morphology and substrate tests will be performed following established methods and genotypic analysis will be conducted through amplification of the nodC gene and 16S rRNA. Next, FP will be inoculated with each native rhizobium isolate, along with a commercial inoculant and uninoculated controls, and planted in a growth chamber. The plants will be subjected to zero, mild and severe salt stress. Nitrogen fixation, nodulation, biomass production and yield will be measured to identify the most salt-tolerant field pea-rhizobia pairs. In the second track, field studies will be conducted with farmer-collaborators in South Dakota under typical farm operations with high-salt conditions. We will select a panel of cultivars to be screened in the field against different commercial inoculants (e.g. liquid, granular, peat) with respect to N fixation and yield under stress conditions.