2018
Evaluation of Soybean Tolerance to Salinity, Alkalinity and the Combined Saline-Alkalinity
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Contributor/Checkoff:
North Dakota Soybean Council
Category:
Sustainable Production
Keywords:
Abiotic stressAgricultureLand Use Water supply
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Qi Zhang, North Dakota State University
Co-Principal Investigators:
Project Code:
QSSB
Contributing Organization (Checkoff):
North Dakota Soybean Council
$19,408
Leveraged Funding (Non-Checkoff):
N/A
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Institution Funded:
North Dakota State University
$19,408
Brief Project Summary:

Soybean is the largest source of animal protein feed and the second largest source of vegetable oil in the world. The United States is the leading soybean producer and exporter. Over 80 million acres of soybean are planted annually in the United States and nearly 6 million acres (7%) are in North Dakota.
High soil salinity is a common problem in North Dakota. The salt-affected soil has expanded from 2.6 million acres in 1987 to 5.8 million acres in 2010 in North Dakota and further expansion is expected. Excessive salt in the soil causes osmotic stress (i.e. physiological drought), ion toxicity, and nutrient imbalance in plants, resulting in reduced growth or even death under the severe...

Unique Keywords:
#environmental stress
Information And Results
Project Deliverables

The results from Objective 1 - developing screening method were presented as a poster at the 2018 annual American Society of Agronomy – Crop Science Society of American conference at Baltimore, MD. Results from this project will be submitted to peer-reviewed journals for a broad audience as well.

Final Project Results

Updated January 3, 2019:
Please see the attached file

View uploaded report Word file

High soil salinity is a common problem in North Dakota, resulting in reduced growth/yield or even death under the severe condition. Previous research on screening salt-tolerant plants was mainly conducted using chloride salts (e.g., NaCl). In North Dakota, the predominant forms of salinity are sulfate salts (mostly Na2SO4 and MgSO4), while chloride-salinity is only seen in the eastern Grand Forks. Information on soybean responses to sulfate-salinity is scarce. Iron-deficiency chlorosis (IDC) is commonly seen in the high pH soil (pH > 7) (i.e. alkalinity) in North Dakota. Research on soybean tolerance to IDC has been well documented. However, a fast and reliable screening method for alkalinity tolerance needs to be developed for genotype evaluation. Salinity and alkalinity often coexist in nature. Limited information is available on soybean responses to the combined saline-alkalinity stress.

We conducted this project to develop screening methods for soybean tolerance to sulfate-salinity, alkalinity, and saline-alkalinity and identify genotypes with high tolerance to the aforementioned stresses.

Our results showed that NaCl was more detrimental to soybean plants, causing severe damage at 4 dS m-1 and plant death at 8 dS m-1 after three weeks of saline exposure. Plants survived at 16 dS m-1 under sulfate-salinity (a Na2SO4 +MgSO4 mixture) and growth inhabitation did not occurred until 8 dS m-1. Alkalinity (pH = 7.3 – 9.4) also reduced soybean growth. Tissue biomass was reduced at pH of 7.3, lower than that for leaf chlorosis to be detected (= 8.8). The combined stress caused higher growth reduction compared to salinity and alkalinity alone. All stresses caused increased Na but decreased K and Ca uptake in shoot. Alkalinity and saline-alkalinity also affected Fe, Mn, and Zn absorption.

Fifty genotypes, including 9 glyphosate-resistant and 41 non-resistant ones, were evaluated for the tolerance to salinity (Na2SO4+MgSO4 at 8 dS m-1), alkalinity (pH = ~9.0), and the combined saline-alkalinity. Genetic differences were detected mostly in shoot and root dry weight and leaf size, but not in leaf chlorosis. Genotypes with high tolerance to salinity and/or alkalinity did not all perform well under the combined stress.

Soybean breeders can use our protocols to screen for high tolerance to salinity, alkalinity, and saline-alkalinity and incorporate the plant materials identified in this research into different breeding purposes. Our research also expands growers’ knowledge on the effects of salinity (salt type and concentration), alkalinity, and their interaction on soybean growth.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.