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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #408379
Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Title: Can cultivar variation in yield help differentiate mechanisms underlying nutrient decline of soybean grown under elevated [CO2]?

Author
item DURSTOCK, MARY - University Of Illinois
item Prior, Stephen - Steve
item Runion, George
item SANZ-SÁEZ, ALVARO - University Of Illinois

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/11/2023
Publication Date: 9/15/2023
Citation: Durstock, M., Prior, S.A., Runion, G. B., and Sanz-Saez, A. 2023. Can cultivar variation in yield help differentiate mechanisms underlying nutrient decline of soybean grown under elevated [CO2]? [ABSTRACT]. Plant Environmental Physiology Group (PEPG) Workshop 2023. Naturasolta-Quinta de Sao Pedro, Portugal, September 10-15, 2023.

Interpretive Summary:

Technical Abstract: Under elevated CO2 concentrations ([CO2]), C3 crops are well understood to increase in yields but nutrient concentration decreases have been observed. With increasing global [CO2], studying mechanisms driving nutrient decline of future crops will be important to adapt crops for future growth conditions and maintain nutrient density. Two theories aiming to explain nutrient decline under elevated [CO2] are 1. nutrient dilution, elevated [CO2] stimulates carbohydrate accumulation greater than nutrient accumulation and 2. the transpiration hypothesis, elevated [CO2] decreases stomatal conductance therefore reducing mass flow and nutrient uptake. These theories are not thought to act independently and are among other theories proposed to explain potential nutrient decline. In the present study, two cultivars with contrasting yield and year of release (YOR) (Wabash, YOR 1948 and LD00-3309, YOR 2005) were grown in open top chambers at the USDA Soil Dynamics Laboratory in Auburn, AL at ambient (~410 ppm) and elevated (ambient + 200ppm) [CO2]. Leaf level gas exchange measurements were used to study physiological responses to elevated [CO2] that drive potential nutrient dilution and transpiration hypotheses. Nutrient dilution was apparent in higher seed dry weights and lower nutrient concentrations of soybeans grown under elevated [CO2] but is not acting alone as not all nutrients decreased proportional to the seed weight increase. Differences in diurnal stomatal conductance and [Mg], [Ca], and [S] between LD00-3309 and Wabash provide evidence of cultivar variation in transpiration that may underpin different concentrations of nutrients regulated by mass flow.