Carbon dioxide enrichment effects on concentration, partitioning and uptake of metallic micronutrient elements in soybean under varied nitrogen application rates

Abstract

Information on the fate of micronutrients in plant tissue and total uptake from soil upon exposure to elevated carbon dioxide (CO₂) is meager. Hence, this field study was conducted in open top field chambers to investigate the effects of elevated CO₂ and applied nitrogen (N) on partitioning and uptake of zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn) in soybean crop under two CO₂ and four N levels during 2016 and 2018 crop seasons. The two CO₂ concentrations were ambient and elevated (∼550 µmol mol⁻¹). Nitrogen treatments included application at 0, 50, 100, and 150% of the recommended dose. Significant effects of CO₂ and N were observed on grain yield, biomass and uptake of the four micronutrients. Seed Fe concentration was significantly increased by 12% under CO₂ enrichment. Tukey’s post-hoc test revealed significantly higher grain yield, biomass and uptake of micronutrients in seed and straw under CO₂ elevation and at higher N application. Uptake of Fe, Zn, Cu, and Mn increased by 53, 42, 36, and 41%, respectively, in seed and by 25, 26, 31, and 18% in straw under elevated CO₂. Total uptake of Fe, Zn, Cu, and Mn increased by 39, 38, 34, and 29%, respectively. Nitrogen at 100% level enhanced uptake of Fe, Zn, Cu, and Mn by 25, 20, 32, and 28%. The study bears implications in micronutrient management for sustaining soil health under changing climate.

Keywords:

• Additional climate change impact on soil nutrient pool
• CO₂ elevation impact
• CO₂ fertilization
• Micronutrient uptake
• Nutrient mining from soil
• Open top chamber

Disclosure statement

The authors declare no conflict of interest as the research work was carried out under a financial grant from the National Agricultural Science Fund of the Indian Council of Agricultural Research, New Delhi, which is a public funded government organization.

Availability of data and materials

The data of the manuscript can be accessed for scientific use with a reasonable request to the corresponding author.

Additional information

Funding

This work was fully funded by a competitive research grant from the National Agricultural Science Fund of the Indian Council of Agricultural Research, New Delhi (Grant No. NASF/CA/5019/2015-16), with the first author as the Principal Investigator.