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Author ORCID Identifier

https://orcid.org/0009-0001-1339-4606

Date Available

4-10-2026

Year of Publication

2026

Document Type

Master's Thesis

Degree Name

Master of Agriculture (MAgr)

College

Agriculture, Food and Environment

Department/School/Program

Plant and Soil Sciences

Faculty

Chad Lee

Faculty

Arthur Hunt

Abstract

Cover crops are reported to have long-term soil health improvements, one of which is reducing erosion. However, popular cereal cover crops, such as rye (Secale cereale L.), have the potential to cause a yield penalty in the following corn (Zea mays L.) crop due to a reduction in available nitrogen. Legumes, such as Austrian winter pea (Pisum sativum L. var. arvense), are thought to reduce this yield penalty due to their capacity to fix nitrogen. Sulfur is another nutrient of interest, especially as rates of atmospheric deposition of sulfur have declined, leading to more deficiencies being observed. The main objective of these studies is to determine how management of a cover crop, through species selection and termination timing, can reduce its effect on the next corn crop. Cover crop treatments include no cover crop control, barley (Hordeum vulgare L.) alone as well as in a mix with Austrian winter pea. Cover crops were terminated at either five or two weeks before corn planting was anticipated. Five nitrogen rates ranging from 45 to 391 kg N ha-1 were applied to corn. Early termination of the cover crops led to less above ground biomass and lower C:N of the cover crop. However, cover crop termination did not significantly impact corn grain yields, possibly influenced by high rainfall amounts both planting seasons. A second study was conducted looking at sulfur needs in corn following a cover crop. Treatments include the same cover crops as the first study, 0 or 34 kg S ha-1, and two moderate nitrogen rates. Corn yield response to sulfur was variable based on site-year. A partial budget analysis was also conducted to evaluate the profitability of both cover crops and sulfur fertilizer, in which there was a 59% change of farmers being profitable by applying sulfur.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2026.36

Archival?

Archival

Funding Information

This study was supported by the Kentucky Corn Promotion Council from 2024-2026

This study was supported by the United States Department of Agriculture-National Insititute of Food and Agriculture Hatch Project from 2024-2026

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