Agriculture Reference
In-Depth Information
In soybean, insect pests have been relatively rare until recently. In 2000 the soy-
bean aphid (
Aphis glycines
Matsumura) invaded the NCR and has required wide-
spread insecticide application (Landis et al. 2008). Major efforts are under way to
understand biological regulation of this pest (Landis and Gage 2015, Chapter 8
in this volume). Other soil-inhabiting organisms such as the soybean cyst nema-
tode also can reduce soybean yields and increase the cost of soybean production
(Kaitany et al. 2000) by requiring management such as crop rotation, resistant vari-
eties, nematicide application, or other cultural practices.
The Emergence of Agricultural Ecology
Many plant pathogens and insect pests flourish in large-scale crop production
systems and are favored by the reduced use of crop rotations (Oerke 2007). Crop
surveillance is a key factor in the early detection and control of such outbreaks.
Although more farmers are beginning to apply principles of ecosystem manage-
ment, such as scouting, to their cropping systems, there is limited coordination of
such activities at regional scales (Isard et al. 2005).
In the 1970s, after years of attempting to manage agricultural insect pests with
an arsenal of chemical inputs such as the insecticide DDT, the environmental risks
of pesticide use were discovered. This, along with publications by Carson (1962)
and others (Pimentel 1971, Van Den Bosch 1978), stimulated the need for a shift
from indiscriminate pesticide use and the development of new approaches to pest
control.
In response, insect ecologists developed the paradigm of Integrated Pest
Management (IPM)—based on the greater use of ecological understanding and bio-
logical methods for pest regulation, such as intensive scouting prior to chemical use
and using natural enemies of pests for biocontrol (Radcliffe et al. 2008). Integrated
Pest Management challenged industrial agriculture's assumption that reliance on
chemicals was the only effective means to manage and maintain production and
economic capacity (Pimentel 1981). The controversy over chemical vs. biological
pest management raged during the 1970s, at a time when corn and soybean produc-
tion was vastly increasing on account of export demand. In the 1980s, the concepts
of Sustainable Agriculture (Robertson and Harwood 2013) and Integrated Farming
Systems emerged. Finally an ecosystem perspective became a lens through which
to examine agriculture, and agricultural ecology had begun to mature as a scientific
discipline (Tivy 1990, Soule and Piper 1992, Altieri 1987).
Climate and Crop Yields in the North Central Region
Patterns of Corn and Soybean Yield
Figure 4.2A shows the county-level percentage of NCR land area classified as suit-
able for agricultural production (i.e., arable land) without regard to water availabil-
ity. Soil water-holding capacity (Fig. 4.2B) provides additional information about
crop production potential.
