Tillage and nitrogen management effects on crop yield and residual soil nitrate

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Bakhsh, Allah
Bailey, Theodore
Kanwar, Rameshwar
Karlen, Douglas
Cambardella, Cynthia
Moorman, Thomas
Colvin, Thomas
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Kanwar, Rameshwar
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As leaders in statistical research, collaboration, and education, the Department of Statistics at Iowa State University offers students an education like no other. We are committed to our mission of developing and applying statistical methods, and proud of our award-winning students and faculty.
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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.

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.

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  • Department of Agricultural Engineering (1907–1990)

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Tillage and N management can have great impact on crop yield and off-site transport of nitrate-nitrogen (NO 3 -N). This six-year field study on tile-drained Clyde-Kenyon-Floyd soils in northeast Iowa was conducted to quantify corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) yield and residual soil NO 3 -N. Eight treatments (chisel plow vs no-tillage by preplant versus late-spring N-management for both corn and soybean phases of a rotation) were evaluated using a randomized complete block design. Preplant N was applied by injecting liquid urea-ammonium nitrate solution (UAN) at a rate of 110 kg N ha 1 . Late-spring soil-test based N-rates averaged 179 and 156 kg N ha 1 for no-till and chisel treatments, respectively. No additional N was applied to soybean. Average corn yield on chisel plots was significantly (P = 0.05) higher than with no-tillage for both preplant (7.9 vs 6.9 Mg ha 1 ) and late-spring (8.6 vs 8.1 Mg ha 1 ) N-management. Average soybean yield where corn had received preplant N (3.6 Mg ha 1 ) was significantly (P = 0.05) greater than where late-spring N-management (3.4 Mg ha 1 ) was used. Residual tillage effects did not significantly (P = 0.05) affect soybean yield. The average residual soil NO 3 -N to a depth of 1.2 m following corn was significantly (P = 0.05) lower for preplant (21 kg N ha 1 ) than late spring (29 kg N ha 1 ) N-management under no-till system, presumably reflecting differences in N application rates. Residual soil NO 3 -N following soybean was significantly (P = 0.05) lower in no-till (28 kg N ha 1 ) than chisel (37 kg N ha 1 ) plots. Average over-winter changes in residual soil NO 3 -N were greatest in corn plots previously fertilized with a single preplant application (+13 to 18 kg N ha 1 ) and most variable following soybean in plots where corn was fertilized based on late-spring nitrate test (LSNT) values (-8.5 to +6.3 kg N ha 1 ). Therefore development of efficient N-management strategies may require complete understanding of N-cycling processes taking place in the soil profile over winter months. The results of the study demonstrate that chisel plow increased corn yield with late-spring N-management and with preplant N when compared to no-till system.


This article is published as Bakhsh, A., R. S. Kanwar, D. L. Karlen, C. A. Cambardella, T. S. Colvin, T. B. Moorman, and T. B. Bailey. "Tillage and nitrogen management effects on crop yield and residual soil nitrate." Transactions of the ASAE 43, no. 6 (2000): 1589. DOI: 10.13031/2013.3059. Posted with permission.

Sat Jan 01 00:00:00 UTC 2000