Agriculture Reference
In-Depth Information
Figure 4.1
. Land use or cover in the North Central Region (NCR) of the United States.
Created from the USDA NASS Cropland Data Layers (NASS 2009b). States in the NCR
include Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North
Dakota, Ohio, South Dakota, and Wisconsin.
opportunity to investigate trends and patterns of crop production ranging from local
to regional scales within the NCR.
As in any other ecosystem, production in cropping systems is determined by abi-
otic and biotic factors. Climate, soils, and nutrient availability can be abiotic con-
straints to producing a profitable crop. Biotic constraints include the yield potential
of a given crop cultivar plus potential losses to weeds, insect herbivores, and plant
pathogens. Management practices such as tillage, irrigation, fertilizers, and pes-
ticides are attempts to attain crop yield potentials by overcoming limitations of
climate, soil fertility, and pests and to favor agriculture in settings where it might
otherwise be less productive. These practices have economic consequences for both
growers and consumers, and often come at an environmental cost (Matson et al.
1997, Tilman et al. 2002, Robertson et al. 2004).
Climate regulates crop growth and productivity. Heat and precipitation are two
important climatic drivers that operate at multiple spatial scales and are the princi-
pal physical determinants of crop yield. In this chapter, we present a simple Crop
Stress Index (CSI), based on data sets of temperature and precipitation, which cap-
tures the main effect of climate on crop yields. We also compare the relationship
between CSI and crop yields at county and regional levels. We end the chapter by
addressing the implications of climate change projections for row-crop production
in the NCR. In an era of incipient climate change impacts (IPCC 2013, Walsh et al.
2014) that will affect the NCR in ways not yet fully understood, it is crucial to have
