Date of Award
3-24-2021
Document Type
Thesis
Degree Name
Environmental Sciences, MS
First Advisor
Steven Green
Second Advisor
Joseph Massey
Committee Members
Aaron Shew; Ahmed Hashem; Arlene Adviento-Borbe; Mohamed Milad
Call Number
LD 251 .A566t 2020 B87
Abstract
Research plots were established on production farms in no-tillage, corn-soybean rotations following a winter cover crop. Independent variables included fertilizer N-application (0, 62, 124, 185, 247 and 309 kg N ha-1) and the presence or absence of a winter cover crop. Yield optimum nitrogen rates (YONR) estimated using linear plateau models ranged from 69.7 to 214.1 kg N ha-1, well below the University of Arkansas’ recommendation of 247 kg N ha-1. Relative to these YONRs, dynamic N-recommendation systems like N-Star, and pre-sidedress available nitrogen (PSAN) reduced recommended N-application rate with little risk of insufficient N-supply. Other recommendations like the Soil Health Test (SHT) recommended greater N-reductions but with a greater risk of N-insufficiency. In addition to soil-based N-tests, remote sensing indices proved to be powerful predictors of corn grain yield. These indices may be useful for detecting N-deficiency during the late vegetative or early reproductive growth stages. During the V8 growth stage, regressions of corn grain yield by index value produced R2 values of 0.84, 0.89, and 0.89 for Red-Edge Normalized Difference Vegetation Index, Chlorophyll Index Green, and the Green Normalized Vegetation Index, respectively. Through remote sensing indices and dynamic soil nitrogen tests, nitrogen use efficiency in no-tillage corn soybean rotations following a winter cover crop may be improved without compromising agronomic or economic goals.
Rights Management
This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
Burns, Brayden William, "Impact Of Winter Cover Crops and Nitrogen Recommendations for Corn-Soybean Rotation in Northeast Arkansas" (2021). Student Theses and Dissertations. 347.
https://arch.astate.edu/all-etd/347
