Excerpt
ENTOMOLOGISTS regularly study insect pests in no-till corn (20), but they neglect pests in renovatad pastures and hayfields, pests such as insects, mites, slugs, and snails. In fact, many scientists attribute legume-establishment failures to soil wetness or dryness factors, grass and weed competition, or poor seed germination when insects and slugs are partly or solely responsible.
Coping with pests in conservation tillage of legumes requires an understanding of grassland ecology. Some researchers (18) ascribe to the dogma that “all ecosystems tend towards stability, and the more diverse and complex the ecosystem, the more stable it is.” The aim of agricultural management, they say, should be to hold plant communities in an immature state. That necessitates fighting these biological agents in the ecosystem that constantly invade artificially produced “young fields,” hastening succession toward climax by favoring survival of woody species. Plant-eating insects, in some cases, may actually determine the composition of vegetation (23).
Other researchers (40) believe that in simplified ecosystems, such as agriculture, one is not justified in assuming that any increase in diversity will have a stabilizing effect. They contend, for example, that hedgerows on farmland increase diversity but offer refuge for …
Footnotes
R. A. Byers is a research entomologist at the U.S. Regional Pasture Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, University Park, Pennsylvania 16802. R. L. Mangan, formerly a research associate at Pennsylvania State University, is now involved in screwworm research with ARS, USDA, Box 986, Mission, Texas 78572. W. C. Templeton, Jr., is a research agronomist and director of the U.S. Regional Pasture Research Laboratory. Contribution No. 8301 of the U.S. Regional Pasture Research Laboratory; authorized as paper No. 6618 in the Journal Series of the Pennsylvania Agricultural Experiment Station.
- Copyright 1983 by the Soil and Water Conservation Society
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.