Response of Different Crop Cultivars to Micronutrient Fertilization and Relationship to Rhizosphere Soil Properties

ABSTRACT

Five different cultivars each of wheat, pea, and canola were grown with and without copper (Cu), zinc (Zn), and boron (B) fertilization, respectively, in a greenhouse study to identify any crop cultivar and rhizosphere soil responses to micronutrient fertilization. The prairie agricultural surface soils (0–10 cm) used in the study were suspected to be micronutrient deficient according to soil extractable levels. Only durum wheat (CDC Fortitude) produced greater biomass from Cu fertilization compared to the other wheat cultivars. Cultivar dependent responses of pea and canola biomass yield to Zn and B fertilization were not significantly (P > .05) different. Boron concentration in whole plant canola tissue increased following fertilizer addition. Micronutrient fertilization increased concentrations and supply rates of available Cu, Zn, and B in post-harvest rhizosphere soil. Fertilizer Cu and Zn were distributed in labile soil solution-carbonate-exchangeable and oxyhydroxide fraction, whereas B was primarily found in the hot water-soluble fraction, specifically adsorbed and oxyhydroxide fractions. The composition of low molecular weight organic acids (formic, propionic, malic, and fumaric acid) in the rhizosphere soil varied among crops. Additionally, citric and tartaric acid were present in the pea and canola rhizosphere soils, respectively. The rhizosphere soil of durum wheat not fertilized with Cu contain higher levels of succinic acid compared to the other wheat cultivars. For pea and canola, there was no significant (P > .05) effect of cultivar on the amounts or forms of organic acids in the rhizosphere soils.

KEYWORDS:

• Rhizosphere
• organic acids
• crop and cultivar response
• micronutrient fertilization
• biomass yield

Acknowledgments

The authors gratefully acknowledge the financial support by the Western Grains Research Foundation and AAFC Agri-Innovation Program. The author sincerely acknowledges McDonald Donkuru for technical assistance in measuring organic acids in our rhizosphere soils. We also thank the Reviewers for their time and critical feedback that improved our manuscript.

Disclosure statement

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was financially supported by the Western Grains Research Foundation and Agriculture and Agri-Food Canada Agri-Innovation Program.