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Wheat breeding nursery planted into a winter wheat/summer fallow rotation |
Wheat in a winter wheat/summer fallow rotation |
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Warning sign posted along the interstate highway, near Pendleton, Oregon |
Dust blowing from a field during the summer fallow cycle of a winter wheat/summer fallow rotation |
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Rill erosion on a steep slope during the summer fallow cycle of a winter wheat/summer fallow rotation; rill erosion also occurs on fields that are nearly flat |
Soil moving in water discharged from an area where winter wheat/summer fallow rotations are common |
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Wheat drilled directly into wheat stubble |
Canola drilled directly into wheat stubble |
Sustainability of Agriculture in a Semi-arid Environment
Precipitation in the Pacific Northwest "wheat belt" occurs mostly from autumn to spring, with little effective rainfall during the summer. Amounts of precipitation are variable from season to season, and most wheat is produced in regions with mean annual rainfall amounts from 10 to 16 inches. This environment is generally not favorable for spring crops that depend on stored soil water as they mature during hot, dry weather. Winter wheat has been the most economical crop, and winter wheat (10-month growing season) rotated with summer fallow (14-months) has been the most profitable production system. This system and the use of a single crop species have been responsible for damage from many soil-borne plant pathogenic fungi, and from erosion of soil by water and wind. Economic and environmental incentives are causing many growers to explore crops and cropping systems to replace the winter wheat/summer fallow rotation. Transitions in the importance of diseases occur as the cropping frequency is increased and intensity of tillage is reduced. Representative papers include the following.
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Smiley, R., M. Siemens, T. Gohlke, and J. Poore. 2005. Small grain acreage and management trends for eastern Oregon and Washington. Oregon Agric. Exp. Sta. Spec. Rep. 1061:30-50. (http://eesc.orst.edu/agcomwebfile/edmat/html/SR/SR1061/3.htm)
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Chen, C., W.A. Payne, R.W. Smiley, and M.A. Stoltz. 2003. Yield and water-use efficiency of eight wheat cultivars planted on seven dates in northeastern Oregon. Agronomy Journal 95:836-843.
- Paulitz, T., R. Smiley, and R.J. Cook. 2002. Insights into the prevalence and management of soilborne cereal pathogens under direct seeding in the Pacific Northwest U.S.A. Canadian Journal of Plant Pathology 24:416-428.
- Ogg, A.G., Jr., R.W. Smiley, K.S. Pike, J.P. McCaffrey, D.C. Thill, and S.S. Quisenberry. 1999. Integrated pest management for conservation systems. pp. 97-128. In. E.L. Michalson , R.I. Papendick, and J.E. Carlson (eds.). Advances in Conservation Farming. CRC Press, Boca Raton , LA. 233 p.
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Rasmussen, P.E., S.L. Albrecht, and R.W. Smiley. 1998. Soil C and N changes under tillage and cropping systems in semi-arid Pacific Northwest agriculture. Soil and Tillage Research 47:197-205.
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Smiley, R.W., H.P. Collins, and P.E. Rasmussen. 1996. Diseases of wheat in long-term agronomic experiments at Pendleton , Oregon . Plant Disease 80:813-820.
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Smiley, R.W. 1996. Diseases of wheat and barley in conservation cropping systems of the semi-arid Pacific Northwest. American Journal of Alternative Agriculture 11:95-103.
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Rasmussen, P.E., R.W. Smiley, and S.L. Albrecht. 1996. Long-term residue management experiment: Pendleton, Oregon USA . pp. 391-396. In. D.S. Powlson, P. Smith, and J.U. Smith (eds.). Evaluation of Soil Organic Matter Models Using Existing, Long-Term Datasets. Springer-Verlag, Berlin. 429 p.
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Rasmussen, P.A. and R.W. Smiley. 1996. Soil carbon and nitrogen change in long-term agricultural experiments at Pendleton, Oregon. p. 353-360. In. E.A. Paul, K. Paustian, E.T. Elliott, and C.V. Cole, (eds.). Soil Organic Matter in Temperate Agroecosystems. CRC Press, Boca Raton, FL. 414 p.
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Duff, B., P.E. Rasmussen, and R.W. Smiley. 1995. Wheat/fallow systems in the semi-arid regions of Pacific NW America. pp. 85-111. In. V. Barnett, R. Payne and R. Steiner (eds.). Agricultural Sustainability: Economic, Environmental and Statistical Considerations. John Wiley & Sons, London. 266 p.
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Rasmussen, P.E., R.W. Smiley, C.B. Reeder, and B. Duff. 1995. Sustainability of cereal-based systems in semi-arid regions. pp. 50-54. In. Proceedings of the National Agricultural Ecosystem Management Conference, New Orleans, LA. Conservation Technology Information Center, West Lafayette, IN.