Author ORCID Identifier

https://orcid.org/0000-0002-4031-1896

Date Available

3-22-2021

Year of Publication

2021

Document Type

Doctoral Dissertation

Degree Name

Doctor of Philosophy (PhD)

College

Agriculture, Food and Environment

Department/School/Program

Plant and Soil Sciences

Advisor

Dr. Chad D. Lee

Co-Director of Graduate Studies

Dr. Hanna J. Poffenbarger

Abstract

Fall implementation of a rye (Secale cereale L.) cover crop (RCC) prior to spring corn (Zea mays L.) planting is a management practice used to improve soil conservation, water quality, and limit herbicide dependence. However, corn growth and yield following a RCC is often reduced due to early-season nitrogen (N) stress and decreased plant emergence, which can limit RCC adoption. The objective(s) of this research were to evaluate corn agronomic management practices (e.g., N and seeding rate management, in-furrow (IF) starter use) following a RCC and determine which management practices can be used to limit corn stress following a RCC and improve RCC adoption. Field studies were established at three locations in Kentucky between 2017 and 2020. Our results determined IF fertilizer and/or fungicide and an above optimum N fertilizer rate did not improve corn grain yield in any site-year, and no interaction between a RCC was observed. However, a split application (5x5 starter + V6 sidedress) of N fertilizer and an elevated corn seeding rate was observed to improve corn emergence, in-season plant health, and grain yield following a RCC. Overall, our results suggest farmers should look to terminate a RCC earlier (14 – 21d before planting), use a split N application, and increase corn seeding rates to limit potential N stress, plant stand reduction, and yield loss following a RCC.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2021.027

Funding Information

This study was supported by the Kentucky Corn Promotion Council and the United States Department of Agriculture National Institute of Food and Agriculture Hatch Project (no. 1023912) in 2018, 2019 and 2020.

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