Growth and ion accumulation responses of four grass species to salinity

ABSTRACT

Ion inclusion or ion exclusion are the two main strategies developed by plants to tolerate saline environments. Shoot sodium (Na⁺), potassium (K⁺), and calcium (Ca²⁺) in four perennial grass species (tall wheatgrass, Nuttall's alkaligrass, creeping foxtail, and switchgrass) treated with nutrient solution salinity levels ranging from 2 to 32 dS m⁻¹ were measured. As the nutrient solution salinity was increased from 2 to 10 dS m⁻¹, tall wheatgrass, creeping foxtail and Nuttall's alkali grass had increased shoot Na⁺ and decreased Ca²⁺ concentration while maintaining growth suggesting that these species tolerated these changes in shoot ion concentration. In contrast, switchgrass excluded Na⁺ from the shoot and maintained K⁺ and Ca²⁺ concentrations but suffered dramatic shoot dry weight reduction. Thus, the Na⁺ exclusion mechanisms present in switchgrass were less efficient in maintaining growth under the 10 dS m⁻¹ nutrient solution treatment than the Na⁺ inclusion mechanisms used by the other three species.

keywords:

• Tall wheatgrass
• creeping foxtail
• switchgrass
• Nuttall's alkali grass

Acknowledgements

Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture. USDA is an equal opportunity provider and employer. Special recognition goes to Jeff Hemenway, Soil Quality Specialist with the NRCS in Huron SD and to Robert Rennolet (retired), District Conservationist with the NRCS in Menno SD who contributed their time and knowledge during discussions of grass species responses to soil salinity under field situations.