Hostname: page-component-848d4c4894-5nwft Total loading time: 0 Render date: 2024-05-26T13:27:42.042Z Has data issue: false hasContentIssue false
  • English
  • Français

A comparison of conventional and alternative agroecosystems using alfalfa (Medicago sativa) and winter wheat (Triticum aestivum)

Published online by Cambridge University Press:  12 February 2007

Laura E. Skelton  and
Gary W. Barrett
Laura E. Skelton
Affiliation:
Institute of Ecology, University of Georgia, Athens, Georgia, 30602, USA.
Gary W. Barrett*
Affiliation:
Institute of Ecology, University of Georgia, Athens, Georgia, 30602, USA.
*
*Corresponding author: gbarrett@uga.edu
Get access Rights & Permissions [Opens in a new window]

Abstract

Natural systems agriculture is based on an understanding that natural systems are self-sustaining due to regulatory mechanisms and processes that help to ensure the long-term maintenance of the ecosystem. An agroecosystem modeled after nature should encompass greater stability and biodiversity at all levels of organization than an agroecosystem based on conventional agricultural practices. The main objective of this study was to determine whether agroecosystems modeled after nature exhibit advantages over conventional agroecosystems. Five treatments were examined: winter wheat (Triticum aestivum L.) monoculture, alfalfa (Medicago sativa L.) monoculture, strip-cropped alfalfa and wheat, and two alfalfa–wheat intercrops (one no-till and one conservation-till). Indicators of ecosystem function studied included primary productivity, soil fertility, plant nitrogen (N) concentration, and abundances of arthropod pests and predators. No fertilizers or pesticides were used prior to or during this investigation. Monoculture, strip-crop and conservation-till treatments produced significantly higher yields than no-till intercropped alfalfa and wheat. Although yields from the no-till intercrop were low, wheat protein values were comparable to other treatments. Soil N concentrations tended to be high in treatments containing alfalfa. Insect pests preferred alfalfa and were, therefore, often more abundant in treatments containing high percentages of alfalfa, as were predators such as spiders. Researching alternatives to monoculture agroecosystems, such as the intercrop systems in this study, may provide us insight into a true natural systems agriculture.

Keywords

agroecosystem ecologyalternative agricultureMedicago sativanatural systems agriculture (NSA)the Land InstituteTriticum aestivum
Type
Research Article
Information
Renewable Agriculture and Food Systems , Volume 20 , Issue 1 , March 2005 , pp. 38 - 47
Copyright
Copyright © Cambridge University Press 2005

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

1Piper, J.K. 1999. Natural systems agriculture. In Collins, W.W. and Qualset, C.O. (eds) Biodiversity in Agroecosystems. CRC Press, Boca Raton, Florida, 167–196.Google Scholar
2Daily, G.C., Alexander, S., Ehrlich, P.R., Goulder, L., Lubchenco, J., Matson, P.A., Mooney, H.A., Postel, S., Schneider, S.H., Tilman, D., and Woodwell, G.M. 1997. Ecosystem Services: Benefits Supplied to Human Societies by Natural Ecosystems. Issues in Ecology No. 2. Ecological Society of America, Washington, DC.Google Scholar
3Barrett, G.W., and Skelton, L.E. 2002. Agrolandscape ecology in the 21st century. In Ryszkowski, L. (ed.). Landscape Ecology in Agroecosystems Management. CRC Press, Boca Raton, Florida. p. 331–339.Google Scholar
4Tilman, D., Wedin, D. and Knops, J. 1996. Productivity and sustainability influenced by biodiversity in grassland ecosystems. Nature 379: 718–720.Google Scholar
5Hooper, D.U. and Vitousek, P.M. 1998. Effects of plant composition and diversity on nutrient cycling. Ecological Monographs 68: 121–149.Google Scholar
6Entz, M.H., Bullied, W.J., Forster, D.A., Gulden, R. and Vessey, J.K. 2001. Extraction of subsoil nitrogen by alfalfa, alfalfa–wheat, and perennial grass systems. Agronomy Journal 93: 495–503.Google Scholar
7Vandermeer, J. 1989. The Ecology of Intercropping. Cambridge University Press, New York.CrossRefGoogle Scholar
8Putnam, D.H. and Allan, D.L. 1992. Mechanisms for overyielding in a sunflower/mustard intercrop. Agronomy Journal 84: 188–195.CrossRefGoogle Scholar
9Haynes, R.J. 1980. Competitive aspects of the grass–legume association. Advances in Agronomy 33: 227–261.Google Scholar
10Pimentel, D. 1995. Amounts of pesticides reaching target pests: Environmental impacts and ethics. Journal of Agricultural and Environmental Ethics 8: 17–29.CrossRefGoogle Scholar
11All, J.N. 1999. Cultural approaches to managing arthropod pests. In Ruberson, J.R. (ed.) Handbook of Pest Management. Marcel Dekker, New York. 395–415.Google Scholar
12Bach, C.E. 1980. Effects of plant density and diversity on the population dynamics of a specialist herbivore, the striped cucumber beetle, Acalymma vittata (Fab.). Ecology 61: 1515–1530.Google Scholar
13Letourneau, D.K. and Altieri, M.A. 1983. Abundance patterns of a predator, Orius tristicolor (Hemiptera: Anthocoridae), and its prey, Frankliniella occidentalis (Thysanoptera: Thripidae): Habitat attraction in polycultures versus monocultures. Environmental Entomology 12: 1464–1469.Google Scholar
14Root, R.B. 1973. Organization of a plant–arthropod association in simple and diverse habitats: the fauna of collards (Brassica oleracea). Ecological Monographs 43: 95–124.Google Scholar
15Vinson, S.B. 1981. Habitat location. In Norlund, D.A., Jones, R.L. and Lewis, W.J. (eds). Semiochemicals: Their Role in Pest Control. John Wiley and Sons, New York. 51–77.Google Scholar
16Roda, A.L., Landis, D.A. and Coggins, M.L. 1997. Forage grasses elicit emigration of adult potato leafhopper (Homoptera: Cicadellidae) from alfalfa–grass mixtures. Environmental Entomology 26: 745–753.Google Scholar
17Degooyer, T.A., Pedigo, L.A. and Rice, M.E. 1999. Effect of alfalfa–grass intercrops on insect populations. Environmental Entomology 28: 703–710.Google Scholar
18Russell, E.P. 1989. Enemies hypothesis: A review of the effect of vegetational diversity on predatory insects and parasitoids. Environmental Entomology 18: 590–599.CrossRefGoogle Scholar
19Mead, R. and Willey, R.W. 1980. The concept of a ‘land equivalent ratio’ and advantages in yields from intercropping. Experimental Agriculture 16: 217–228.Google Scholar
20Association of Organic and Analytical Chemists 2000. AOAC official method 968.06: Protein (crude) in animal feed. In Horowitz, W. (ed.) Official Methods of Analysis of AOAC International. 17th ed. AOAC International, Gaithersburg, Maryland. p. 21–23.Google Scholar
21Zolman, J.F. 1993. Biostatistics: Experimental Design and Statistical Inference. Oxford University Press, New York.Google Scholar
22Zimdahl, R.L. 2002. Moral confidence in agriculture. American Journal of Alternative Agriculture 17: 44–53.Google Scholar
23Knapp, A.K., Briggs, J.M., Blair, J.M. and Turner, C.L. 1998. Patterns and controls of aboveground net primary production in tallgrass prairie. In Knapp, A.K., Briggs, J.M., Hartnett, D.C. and Collins, S.L. (eds) Grassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie. Oxford University Press, New York. p. 193–221.Google Scholar
24Towne, G. and Owensby, C. 1984. Long-term effects of annual burning at different rates in ungrazed Kansas tallgrass prairie. Journal of Range Management 37: 392–397.Google Scholar
25Carr, P.M., Gardner, J.C., Schatz, B.G., Zwinger, S.W. and Guldan, S.J. 1995. Grain yield and weed biomass of a wheat–lentil intercrop. Agronomy Journal 87: 574–579.Google Scholar
26Wheatley, D.M., Macleod, D.A. and Jessop, R.S. 1995. Influence of tillage treatments on N 2 fixation of soybean. Soil Biology and Biochemistry 27: 571–574.Google Scholar
27Horn, C.P., Birch, C.J., Dalal, R.C. and Doughton, J.A. 1996. Sowing time and tillage practice affect chickpea yield and nitrogen fixation: 1. Dry matter accumulation and grain yield. Australian Journal of Experimental Agriculture 36: 695–700.CrossRefGoogle Scholar
28Keeney, D.R. 1982. Nitrogen management for maximum efficiency and minimum pollution. In Stevenson, F.J. (ed.) Nitrogen in Agricultural Soils. Wisconsin American Society of Agronomy, Madison, p. 605–649.Google Scholar
29Groffman, P.M., House, G.J., Hendrix, P.F., Scott, D.E., Crossley, D.A. Jr. 1986. Nitrogen cycling as affected by interactions of components in a Georgia Piedmont agroecosystem. Ecology 67: 80–87.CrossRefGoogle Scholar
30Neely, C.L., McVay, K.A. and Hargrove, W.L. 1987. Nitrogen contribution of winter legumes to no-till corn and grain sorghum. In Power, J.F. (ed.). The Role of Legumes in Conservation Tillage Systems. Iowa Soil Conservation Society of America, Ankeny, p. 48–49.Google Scholar
31Blair, J.M., Seastedt, T.R., Rice, C.W. and Ramundo, R.A. 1998. Terrestrial nutrient cycling in tallgrass prairie. In Knapp, A.K., Briggs, J.M., Hartnett, D.C. and Collins, S.L. (eds) Grassland Dynamics: Long-Term Ecological Research in Tallgrass Prairie. Oxford University Press, New York, p. 222–243.Google Scholar
32Brophy, L.S., Heichel, G.H. and Russelle, M.P. 1987. Nitrogen transfer from forage legumes to grass in a systematic planting design. Crop Science 27: 753–758.Google Scholar
33Brady, N.C. and Weil, R.R. 2000. Elements of The Nature and Properties of Soils. Prentice Hall, Upper Saddle River, New Jersey.Google Scholar
34Peoples, M.B., Bowman, A.M., Gault, R.R., Herridge, D.F., McCallum, M.H., McCormick, K.M., Norton, R.M., Rochester, I.J., Scammell, G.J. and Schwenke, G.D. 2001. Factors regulating the contributions of fixed nitrogen by pasture and crop legumes to different farming systems of eastern Australia. Plant and Soil 228: 29–41.Google Scholar
35Kansas Agricultural and Statistics Service 2001. Kansas Wheat Quality 2002. KASS, 632 SW Van Buren, Room 200, P.O. Box 3534, Topeka, Kansas 66601–3534.Google Scholar
36Holmes, D.W. and Barrett, G.W. 1997. Japanese beetle (Popillia japonica) dispersal behavior in intercropped vs. monoculture soybean agroecosystems. The American Midland Naturalist 137: 312–319.Google Scholar
37Joern, A. and Gaines, S.B. 1990. Population dynamics and regulation in grasshoppers. In Chapman, R.F. and Joern, A. (eds) Biology of Grasshoppers. John Wiley and Sons, New York. p. 415–482.Google Scholar
38Byrne, H.D. 1969. The oviposition response of the alfalfa weevil Hypera postica (Gyllenhal). University of Maryland Agricultural Experiment Station Bulletin A-160: 1–42.Google Scholar
39Price, P.W. 1987. The role of natural enemies in insect populations. In Barbosa, P. and Schultz, J.C. (eds). Insect Outbreaks. California Academic Press, San Diego. p. 287–312.Google Scholar
40Stinner, B.R., Brust, G.E. and McCartney, D.A. 1987. Predatory arthropod ecology in conservation tillage systems using legumes. In Power, J.F. (ed.) The Role of Legumes in Conservation Tillage Systems. Soil Conservation Society of America, Ankeny Iowa. p. 73–74.Google Scholar
41Warburton, D.B. and Klimstra, W.D. 1984. Wildlife use of no-till and conventionally tilled corn fields. Journal of Soil and Water Conservation 39: 327–330.Google Scholar
42Byers, R.A., Bahler, C.C., Stout, W.L., Leath, K.T. and Hoffman, L.D. 1999. The establishment of alfalfa into different maize residues by conservation-tillage and its effect on insect infestation. Grass and Forage Science 54: 77–86.Google Scholar
43Jackson, W. 2002. Natural systems agriculture: A radical alternative. Agriculture, Ecosystems, and Environment 88: 111–117.Google Scholar
44Cox, T.S., Bender, M., Picone, C., VanTassel, D.L., Holland, J.B., Brummer, E.C., Zoeller, B.E., Paterson, A.H. and Jackson, W. 2002. Breeding perennial grain crops. Critical Reviews in Plant Sciences 21: 59–91Google Scholar