Economic and Input-use Efficiency of Nitrogen Management Techniques in Non-irrigated Maize Production

Authors

Katie J. Bathke, University of Nebraska - LincolnFollow

Document Type

Thesis

Date of this Version

Winter 2023

Citation

Bathke, Katie, " Economic and Input-use Efficiency of Nitrogen Management Techniques in Non-irrigated Maize Production.” (2023). Undergraduate Honors Theses. University of Nebraska-Lincoln.

Comments

Copyright Katie Bathke 2023.

Abstract

The efficiency of nitrogen (N) management has become a main concern in agricultural cropping systems for understanding the optimal N rate to help producers improve economically and reduce the exhaustion of natural resources environmentally. Nitrogen rates vary both temporally and spatially by the interactions of the soil environment and rainfall through a growing season. Thus, a site-specific approach can further optimize this variability with the understanding of the role soil variability plays in the N rate applied to a non-irrigated field. The objective of this study was to evaluate the various nitrogen treatments for their nutrient use efficiency and economic measures depending on the timing of the treatments. The experimental design was arranged in a randomized complete block design. The nitrogen treatment rates are in the format of NH3_UAN as follows: 80_0, 120_0, 160_0, 200_0, 80_40, 80_80, and 80_120. For example, this reads as 80 lbs NH3_ 0 lbs of 32% UAN applied in the 80_0 treatment. Each treatment rate was also tested with an N stabilizer. The treatment plan also included zero N blocks through the design to serve as a control for the study. Equipment (i.e., precision ag) data of target N rate, applied N rates, and yield data were collected for further analysis of the relationship occurring between total N applied and yield per treatment plan. Normalized Difference Red-Edge (NDRE) reflectance measurements were also collected throughout the growing season to then be converted to geospatial imagery for analysis of crop stress, temporally and spatially throughout the field. In this specific field system, a lower rate of N treatment was economically favored. This indicated the soil had the presence of adequate mineralization prior to any application of N. For the additional rates of N to only yield less than 10 (bu/ac) more than the control would economically favor a lower rate of N for this specific field system.