It comes as no surprise that crops are generally produced in locations most suitable for growing them.
The term ‘suitability’ implies that the ideal mix of weather conditions, soil properties, and resources are available for profitable crop production. While warmer temperatures often promote growth, most crops in the Northeast are already being grown close to their optimum temperature. The region, however, is likely to continue to experience increases in average annual growing season air temperature. The projected 1.5 to 3.5° F degree shift over the next several decades can mean a shift away from ideal conditions, and therefore lead to significant decline in crop productivity.
Agronomists have long identified the connection between crop production and temperature.
These basic temperature relationships help give us insight into the optimum temperature ranges for different crops. For example, the figure below shows different corn and soybean growth rates across a range of temperatures. The different colors represent vegetative and reproductive growth stages. An increase in air temperature can have either a beneficial or a negative impact on growth rate and yield depending on when it occurs and where it falls along the curve. Based on the figure, increasing temperatures beyond 70° F during reproductive phases has a larger impact on soybean reproductive growth rate than on vegetative growth. We can use these relationships to estimate the effect this change can have on crop production. We can also test potential adaptation strategies based on the extent and timing of projected temperature increases.
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Plants also have different sensitivities during their growth cycle to heat stress.
These are not fully captured in the basic temperature relationship. Flowering of cereal crops is a particularly temperature sensitive growth stage. High temperatures can result in pollen sterility and yield loss. For example, long exposure to temperatures above 95° F for corn and 102°F for soybean during their reproductive phase can result in little to no economic yield. The shifts in atmospheric carbon dioxide concentration (CO2), rainfall patterns and intensity, and increased frequency of extreme weather events further complicate this picture. However, simple ‘back to basic’ relationships like those illustrated in the figure can still help researchers understand, explore, experiment, and evaluate different adaptation strategies to aid in land management response to a warming climate. For the Northeast, it may be beneficial to consider planting varieties that are adjusted to warmer conditions and to adjust planting dates to minimize the risk of high temperatures during the reproductive phase.
