Agriculture Reference
In-Depth Information
and no-till farming, which are included in the alternative crop management sys-
tems at the KBS LTER, can reduce the need for chemical subsidies and help man-
age crops under heat and/or water stress (Snapp et al. 2015, Chapter 15 in this
volume). Increasing the organic matter content of soil increases soil water reten-
tion and reduces the need for water subsides, which will likely be required as the
climate warms. Designing landscapes to optimize natural regulation of crop pests
can reduce both crop loss and pesticide use (Landis and Gage 2015, Chapter 8 in
this volume). Not only would such practices help agricultural ecosystems become
more resilient and adaptable to climate change, they also have the potential to miti-
gate future climate change by sequestering carbon and by reducing the footprint of
agronomic chemical use (Paul et al. 2015, Chapter 5 in this volume; Gelfand and
Robertson 2015, Chapter 12 in this volume).
Because corn is more sensitive to heat stress than soybean (see Fig. 4.10), an
immediate concern is whether the NCR will be able to sustain corn production
under climate projections of increased heat and less water. How can farming in the
NCR adapt to such projections? Formulating an answer to that question requires
a long-term perspective based on the integration of both climate and crop produc-
tion, such as in the development of the CSI—because if you cannot measure it,
you cannot manage it. Interpreting and using indices such as the CSI will only
become more important as an unprecedented global population places even greater
demands on agricultural ecosystems for food, fuel, and fiber.
Summary
Since its conversion from prairie and forest following European settlement in the
1800s, the North Central Region (NCR) of the United States has become one of
the most important crop-producing areas in the world. Government subsidies, eco-
nomic forces, industrialization, and consumer preferences combined to shape the
current agricultural landscape of the NCR. Temperature and precipitation patterns
help to drive yield trends at regional and local scales. A simple Crop Stress Index
(CSI) based on temperature and precipitation records across the region shows the
strong climatic influence on yield of rain-fed corn and soybean over 1971-2001;
each unit increase in the CSI results in a yield penalty of 0.14 and 0.04 Mg ha
−1
for
corn and soybean, respectively.
Overall yield trends for Kalamazoo County over 1971-2001, the location of
KBS, are similar to those for the NCR, but crops in Kalamazoo County were
less affected by climatic variability than crops in drier areas in the NCR. At
both local and regional scales, few stress events spanned multiple years dur-
ing this period. With projected changes in temperature and precipitation from
human-induced climate change, crop stress is likely to increase, and with seri-
ous potential consequences. Climate uncertainties make adaptive measures both
crucial and challenging to implement. A regional understanding of agriculture
coupled with an ecosystem-level approach is needed to determine how interact-
ing and ever-changing socioeconomic, climatic, and ecological forces will impact
agriculture in the region.
