Tillage system effects on 15-year carbon-based and simulated N budgets in a tile-drained Iowa field

dc.contributor.author Karlen, Douglas
dc.contributor.author Kumar, Ajay
dc.contributor.author Kanwar, Ramesh
dc.contributor.author Cambardella, Cynthia
dc.contributor.author Kanwar, Rameshwar
dc.contributor.author Colvin, Thomas
dc.contributor.department Agricultural and Biosystems Engineering
dc.date 2018-02-14T16:18:46.000
dc.date.accessioned 2020-06-29T22:40:59Z
dc.date.available 2020-06-29T22:40:59Z
dc.date.embargo 2014-09-21
dc.date.issued 1998-10-02
dc.description.abstract <p>Tillage influences N fate and transport by changing soil structure, aeration, macropore continuity, plant-residue placement, and organic-matter mineralization rates. Our objective was to use 15-year N budgets to compare four primary tillage treatments for continuous corn (<em>Zea mays</em> L.) production on tile-drained Aquic Hapludolls (FAO: Haplic Phaeozems) in northeastern Iowa, USA. A carbon-based N budget used annual grain yield, grain-N concentrations measured in 1992, changes in surface-soil C content between 1977 and 1988 or 1992, surface-soil C : N ratios, and measurements of NO<sub>3</sub>–N lost in tile-drainage water. It accounted for 98, 104, 99, and 99% of the fertilizer N applied to moldboard-, chisel-, ridge-, and no-tillage-treatments, respectively. Averaged for 1977 through 1992, increased soil organic matter, harvested grain, and tile drainage accounted for ≈42, 45, and 13% of the N budget, respectively. Simulated N budgets were computed using version 3.25 of the root-zone water quality model (RZWQM). The best grain-yield predictions for 13 of the 15 years were 9% higher than the measured values, and if extreme outliers were eliminated, the predicted values were correlated (r<sup>2</sup> =0.75) with the average measured yield for the four tillage treatments. Simulations for 1988 and 1989 failed completely because RZWQM could not accurately describe hydrology associated with low rainfall seasons. Predicted total N accumulation was much higher than measured in 1990, 1991, or 1992. Estimates of profile NO<sub>3</sub>–N, mineralization, seepage loss, and denitrification were not satisfactory, presumably because the model failed to simulate an accurate hydrology for the different tillage practices. We conclude that the simulation results were not suitable for predicting the fate of fertilizer N. However, both approaches for computing N budgets suggested that adopting ridge tillage, without changing N rates and other management practices related to N application technology and crop sequencing, will not reduce the potential for off-site water quality degradation.</p>
dc.description.comments <p>This article is from <em>Soil and Tillage Research</em> 48 (1998): 155–165, doi:<a href="http://dx.doi.org/10.1016/S0167-1987(98)00142-1" target="_blank">10.1016/S0167-1987(98)00142-1</a>.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/abe_eng_pubs/577/
dc.identifier.articleid 1860
dc.identifier.contextkey 6143391
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath abe_eng_pubs/577
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/1358
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/abe_eng_pubs/577/1998_Karlen_TillageSystem.pdf|||Sat Jan 15 01:00:13 UTC 2022
dc.source.uri 10.1016/S0167-1987(98)00142-1
dc.subject.disciplines Agriculture
dc.subject.disciplines Bioresource and Agricultural Engineering
dc.subject.disciplines Soil Science
dc.subject.keywords RZWQM
dc.subject.keywords Simulation modeling
dc.subject.keywords C
dc.subject.keywords N ratios
dc.subject.keywords Nitrate
dc.subject.keywords Carbon
dc.subject.keywords Zea mays L.
dc.title Tillage system effects on 15-year carbon-based and simulated N budgets in a tile-drained Iowa field
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication f36d4ee5-a0dc-46fc-9716-9cc7ad1e2871
relation.isAuthorOfPublication 5210e67e-b8da-4e17-be3f-843a09381196
relation.isOrgUnitOfPublication 8eb24241-0d92-4baf-ae75-08f716d30801
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