Campus Units
Agronomy, Agricultural and Biosystems Engineering
Document Type
Article
Publication Version
Published Version
Publication Date
3-1-2017
Journal or Book Title
PloS ONE
Volume
12
Issue
3
First Page
e0172293
DOI
10.1371/journal.pone.0172293
Abstract
Nitrogen fertilization is critical to optimize short-term crop yield, but its long-term effect on soil organic C (SOC) is uncertain. Here, we clarify the impact of N fertilization on SOC in typical maize-based (Zea mays L.) Midwest U.S. cropping systems by accounting for site-to-site variability in maize yield response to N fertilization. Within continuous maize and maize-soybean [Glycine max (L.) Merr.] systems at four Iowa locations, we evaluated changes in surface SOC over 14 to 16 years across a range of N fertilizer rates empirically determined to be insufficient, optimum, or excessive for maximum maize yield. Soil organic C balances were negative where no N was applied but neutral (maize-soybean) or positive (continuous maize) at the agronomic optimum N rate (AONR). For continuous maize, the rate of SOC storage increased with increasing N rate, reaching a maximum at the AONR and decreasing above the AONR. Greater SOC storage in the optimally fertilized continuous maize system than in the optimally fertilized maize-soybean system was attributed to greater crop residue production and greater SOC storage efficiency in the continuous maize system. Mean annual crop residue production at the AONR was 22% greater in the continuous maize system than in the maize-soybean system and the rate of SOC storage per unit residue C input was 58% greater in the monocrop system. Our results demonstrate that agronomic optimum N fertilization is critical to maintain or increase SOC of Midwest U.S. cropland.
Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
File Format
application/pdf
Recommended Citation
Poffenbarger, Hanna J.; Barker, Daniel W.; Helmers, Matthew J.; Miguez, Fernando E.; Olk, Daniel C.; Sawyer, John E.; Six, Johan; and Castellano, Michael J., "Maximum soil organic carbon storage in Midwest U.S. cropping systems when crops are optimally nitrogen-fertilized" (2017). Agronomy Publications. 122.
https://lib.dr.iastate.edu/agron_pubs/122
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Bioresource and Agricultural Engineering Commons
Comments
This article is from PloS ONE 12 (2017): e0172293, doi: 10.1371/journal.pone.0172293.