Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-27T10:43:14.726Z Has data issue: false hasContentIssue false
  • English
  • Français

Reduced chemical input cropping systems in the southeastern United States. II. Effects of moderate rates of N fertilizer and herbicides, tillage, and delayed cover crop plow-down on crop yields

Published online by Cambridge University Press:  30 October 2009

Larry D. King
Larry D. King
Affiliation:
Professor, Department of Soil Science, North Carolina State University, Raleigh, NC 27695-7619.
Get access

Abstract

In a previous study of reduced chemical cropping systems (N from legumes; chisel plow and disk tillage; cultivation for weed control) in the southeastern U.S., corn and wheat yields were less than half those obtained with recommended practices. The following practices were studied as possible ways to improve yields in the reduced chemical systems: 1) conventional tillage (chisel plowing and disking), inorganic Nat 70 or 140 kg/ha, and either cultivation or herbicides; 2) early versus late plow-down of clover green manures; 3) supplemental inorganic N fertilizer on corn and wheat in rotations relying on clover green manures for N; and 4) nicosulfuron herbicide banded on corn.

Yield of soybean in the rotations was not affected by any of these practices. With herbicides and fertilizer N at 140 kg/ha, continuous corn yields with no-till and conventional tillage were equal in 1990 and 1992, but no-till yield was 30% higher in 1991. When cultivation was used for weed control in the conventional tillage treatment, corn yield was similar to that of no-till with herbicide in the one year when rain was plentiful (yield 6000 kg/ha). However, in 2 of 4 dry years, yields (<2600 kg/ha) were higher with no-till. Clover biomass consistently increased by between 700 and 3500 kg/ha when plow-down was delayed from mid-April to early or mid-May (13 to 26 days). However, biomass N content increased significantly (by between 35 and 90 kg/ha) in only 2 of 5 years. Corn yields were affected in only 2 of 12 possible comparisons. In these cases, delayed clover plow-down reduced yield by about 50%. Supplementing corn with 45 kg N/ha and banding nicosulfuron increased yields, but only to between 62 and 84% of yields with recommended practices. Supplementing wheat with 45 kg N/ha increased yields by half, but only to between 40 and 60% of the yields with 90 kg N/ha.

Keywords

reduced chemical systemsbanded herbicidegreen manurecornwheatsoybeancloverno-tillconventional tillageN fertilizer
Type
Research Article
Information
American Journal of Alternative Agriculture , Volume 9 , Issue 4 , December 1994 , pp. 162 - 170
Copyright
Copyright © Cambridge University Press 1994

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Anderson, M. 1990. Farming with reduced synthetic chemicals in North Carolina. Amer. J. Alternative Agric. 5:60–68.CrossRefGoogle Scholar
2.Anderson, J.R., and Wagger, M.G.. (eds). undated. Corn production systems in North Carolina. North Carolina Agric. Extension Service, Raleigh.Google Scholar
3.Andrews, R.W., Peters, S.E., Janke, R.R., and Sahs, W.W.. 1990. Converting to sustainable farming systems. In Francis, C.A., Flora, C.B., and King, L.D. (eds). Sustainable Agriculture in Temperate Zones. John Wiley and Sons, New York, N.Y. pp 281–313.Google Scholar
4.Buhler, D.D., Gunsolus, J.L., and Ralston, D.F.. 1992. Integrated weed management techniques to reduce herbicide inputs in soybean. Agronomy J. 84:973–978.CrossRefGoogle Scholar
5.Ebelhar, S.A., Frye, W.W., and Blevins, R.L.. 1984. Nitrogen from legume cover crops for no-tillage corn. Agronomy J. 76:51–55.CrossRefGoogle Scholar
6.Gallaher, R.N. 1993. Cover crops and nitrogen management for no-tillage corn. Proceedings of the 1993 Southern Conservation Tillage Conference for Sustainable Agriculture,Monroe, Louisiana. Manuscript No. 93-86-7122. Louisiana Agric. Exp. Sta., Baton Rouge, pp. 81–84.Google Scholar
7.Hargrove, W.L. 1986. Winter legumes as a nitrogen source for no-till grain sorghum. Agronomy J. 78:70–74.CrossRefGoogle Scholar
8.Hubbard, N.L. 1986. Management of a hairy vetch (Vicia villosa Roth) cover crop as a nitrogen source and mulch for corn (Zea mays L.). M.S. Thesis, Dept. of Crop Science, North Carolina State Univ., Raleigh.Google Scholar
9.King, L.D., and Buchanan, M.. 1993. Reduced chemical input cropping systems in the southeastern United States: I. Effect of rotations, green manure crops and nitrogen fertilizer on crop yields. Amer. J. Alternative Agric. 8:58–77.CrossRefGoogle Scholar
10.Liebhardt, W.C., Andrews, R.W., Culik, M.N., Harwood, R.R., Janke, R.R., Radke, J.K., and Rieger-Schwartz, S.L.. 1989. Crop production during conversion from conventional to low-input methods. Agronomy J. 81:150–159.CrossRefGoogle Scholar
11.McVay, K.A., Radcliffe, D.E., and Hargrove, W.L.. 1989. Winter legume effects on soil properties and nitrogen fertilizer requirements. Soil Sci. Soc. Amer. J. 53:1856–1862.CrossRefGoogle Scholar
12.Moll, R.H., Kamprath, E.J., and Jackson, W.A.. 1987. Development of nitrogen-efficient prolific hybrids of maize. Crop Sci. 27:181–186.CrossRefGoogle Scholar
13.Oyer, L.J., and Touchton, J.T.. 1990. Utilizing legume cropping systems to reduce nitrogen fertilizer requirements for conservation-tilled corn. Agronomy J. 82:1123–1127.CrossRefGoogle Scholar
14.Poston, D.H., Murdock, E.C., and Toler, J.E.. 1992. Cost-efficient weed control in soybean (Glycine max) with cultivation and banded herbicide applications. Weed Technology 6:990–995.CrossRefGoogle Scholar
15.Ray, A.A. (ed). 1982. SAS Users' Guide: Statistics, 1982 Edition. SAS Institute, Cary, North Carolina.Google Scholar
16.Touchton, J.T., Gardner, W.A., Hargrove, W.L., and Duncan, R.R.. 1982. Reseeding crimson clover as a N source for no-tillage grain sorghum production. Agronomy J. 74:283–287.CrossRefGoogle Scholar
17.van Bavel, C.H.M., and Verlinden, F.J.. 1956. Agricultural drought in North Carolina. Technical Bull. No. 122. North Carolina Agric. Exp. Sta., Raleigh.Google Scholar
18.Wagger, M.G. 1989a. Time of desiccation effects on plant composition and subsequent nitrogen release from several winter annual cover crops. Agronomy J. 81:236–241.CrossRefGoogle Scholar
19.Wagger, M.G. 1989b. Cover crop management and nitrogen rate in relation to growth and yield of no-till corn. Agronomy J. 81:533–538.CrossRefGoogle Scholar