Agriculture Reference
In-Depth Information
Regional Data Processing
Monthly Climate
Dataset
Daily Climate
Dataset
Summarize
to monthly
1053 Counties
1971-2001
30 x 12 x 1053 Observations
Mean Max Temperature (C)
Mean Min Temperature (C)
To tal Precipitation (mm)
Sum of Degree Days (compute)
Crop Stress Index (CSI)
1053 Counties
1971-2001
30 x 365 x 1053 Observations
Max Temperature (C)
Minimum Temperature (C)
Precipitation (mm)
Degree Days (compute)
Compute Crop Stress
Index (CSI) =
(Sum Degree Days)/
(Sum Precipitation + 1)
Crop-Climate
Dataset
Annual Crop
Dataset
Annual Rainfed Crop
Dataset
1053 Counties
1971-2001
Area Planted (ha)
Area Harvested (ha)
Yield (Mg ha
-1
)
1053 Counties
1971-2001
Area Planted (ha)
Area Harvested (ha)
Yield (Mg ha
-1
)
Extract
non-irrigated
Figure 4.6
. Structural organization of the regional database linking daily and monthly cli-
mate variables with annual yields of corn and soybean crops. Growing season degree-days are
based on the average daily temperature (°C) - 10 °C. The climate data set is from the National
Weather Service Cooperative Observer Network. Extrapolations to the 1053 of 1055 counties
in the NCR where data were available were computed by the Midwestern Regional Climate
Center (MRCC) and compiled by the North Central Regional Climate and Crop Committee
(USDA and Cooperating States). See Fig. 4.3 legend for regional crop dataset source.
Crop Stress and Yields
Over the 30-year period of this analysis, technological advances—including new
varieties, nutrient subsidies, soil management, and pest control—have improved
yields of both corn and soybean. Regional yields of both crops trend upward dur-
ing this period and have similar degrees of fit (
r
2
= 0.60 for corn and
r
2
= 0.64 for
soybean, Fig. 4.4). Regional yields of both crops decline, however, with increas-
ing crop stress (Fig. 4.10). The steeper negative slope for corn compared to soy-
bean suggests that corn has a greater sensitivity to climate stress than soybean.
This is consistent with the differential responses of these crops to heat stress: high
