Agronomy and Horticulture, Department of
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
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First Advisor
Ronald Christian Stephenson
Date of this Version
5-2026
Document Type
Thesis
Citation
A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science
Major: Agronomy
Under the supervision of Professor Ronald Christian Stephenson
Lincoln, Nebraska, May 2026
Abstract
Many products are marketed towards potato farmers that purport to have a positive return on investment for yield and quality. Humic acids, which are comprised of long chained, organic molecules that can be naturally or industrially made, are currently being marketed in this way. The use of these materials is reported to improve nutrient uptake, increase soil health, encourage vigorous growth, and most importantly, increase yields. From 2023-2025, the in-furrow application of humic acid containing commercial products was evaluated in Pennsylvania on the cultivars ‘Lehigh’ and ‘Waneta’. Black Label Zn, Duo Maxx, Fertiactyl RhiZn, Humi-flex FA, Hydra-Hume, and Monty's Liquid Carbon were applied directly over the seed piece at planting. Both irrigated and dryland plots were evaluated for emergence, yield, tuber disease incidence, and tuber quality. A separate experiment in 2024 evaluated ‘Lehigh’ plots for nutrient uptake and photosynthetic capacity. Significant differences observed between years, sites, and varieties demonstrated the evaluation power of this study to measure differences in important potato production traits. However, no experiment metric was found to have been impacted by any humic acid product treatment when compared to an untreated control. These data support the conclusion that there is no consistent return on investment to Pennsylvania growers to apply humic acid in-furrow at potato planting.
Advisor: Ronald Christian Stephenson
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Botany Commons, Horticulture Commons, Plant Biology Commons
Comments
Copyright 2026, Jonathan Tyler Price. Used by permission