Impact of nitrogen fertilizer timing on nitrate loss and crop production in northwest Iowa

Waring, Emily Rose; Sawyer, John; Pederson, Carl; Helmers, Matthew

Impact of nitrogen fertilizer timing on nitrate loss and crop production in northwest Iowa

File

2022-SawyerJohn-ImpactNitrogen.pdf (1.33 MB)

Date

2022-05-06

Authors

Waring, Emily Rose

Sawyer, John

Pederson, Carl

Helmers, Matthew

Publisher

Wiley

Authors

Person

Sawyer, John

Contingent Worker Contingent Worker Contingent Worker Contingent Worker Contingent Worker

Person

Helmers, Matthew

Organizational Units

Organizational Unit

Agronomy

The Department of Agronomy seeks to teach the study of the farm-field, its crops, and its science and management. It originally consisted of three sub-departments to do this: Soils, Farm-Crops, and Agricultural Engineering (which became its own department in 1907). Today, the department teaches crop sciences and breeding, soil sciences, meteorology, agroecology, and biotechnology.

History
The Department of Agronomy was formed in 1902. From 1917 to 1935 it was known as the Department of Farm Crops and Soils.

Dates of Existence
1902–present

Historical Names

Department of Farm Crops and Soils (1917–1935)

Related Units

College of Agriculture and Life Sciences (parent college)

Organizational Unit

Agricultural and Biosystems Engineering

Since 1905, the Department of Agricultural Engineering, now the Department of Agricultural and Biosystems Engineering (ABE), has been a leader in providing engineering solutions to agricultural problems in the United States and the world. The department’s original mission was to mechanize agriculture. That mission has evolved to encompass a global view of the entire food production system–the wise management of natural resources in the production, processing, storage, handling, and use of food fiber and other biological products.

History
In 1905 Agricultural Engineering was recognized as a subdivision of the Department of Agronomy, and in 1907 it was recognized as a unique department. It was renamed the Department of Agricultural and Biosystems Engineering in 1990. The department merged with the Department of Industrial Education and Technology in 2004.

Dates of Existence
1905–present

Historical Names

Department of Agricultural Engineering (1907–1990)

Related Units

College of Agriculture and Life Sciences (parent college)
College of Engineering (parent college)
Department of Industrial Education and Technology, (merged, 2004)

Department

AgronomyAgricultural and Biosystems Engineering

Abstract

Nitrate in subsurface tile drainage from Midwestern USA corn (Zea mays L.)-soybean [Glycine max (L.) Merr] systems is detrimental to water quality at local and national scales. The objective of this replicated plot study in Northwest Iowa, 2015–2020, was to investigate the influence of nitrogen (N) fertilizer timing on crop production and NO3 load in subsurface (tile) drainage discharge. Four treatments applied to corn included fall anhydrous ammonia with a nitrification inhibitor (F), spring anhydrous ammonia (S), split-banded urea at planting and mid-vegetative growth (SS), and no N fertilizer (0N). Across crops and years, NO3-N concentration in subsurface drainage discharge was the same 11.7 mg L–1 for F and S applied anhydrous ammonia (AA). Concentration was statistically lower with SS urea (10 mg L–1) than F and S, and 0N was lower than SS at 8.3 mg L–1. Average annual NO3-N loads were not different between any treatments due to plot variability in drainage discharge. Corn responded to N application, with overall mean yield the same for F, S, and SS. There were no agronomic or water quality benefits for applying AA in the spring compared to fall, where the F included a nitrification inhibitor and was applied to cold soils. Split-applied urea had a small positive water quality impact but no crop yield enhancement. This study shows that there were improvements to NO3-N concentration in subsurface drainage discharge, but more nutrient reduction practices are needed than fertilizer N management alone to reduce nitrate load to surface water systems.

Comments

This is the peer-reviewed version of the following article: Waring, Emily Rose, John Sawyer, Carl Pederson, and Matt Helmers. Impact of nitrogen fertilizer timing on nitrate loss and crop production in northwest Iowa (2022), which has been published in final form at DOI: 10.1002/jeq2.20366. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0). Copyright 2022 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. Posted with permission.