Climate is the major factor affecting crop production; therefore, various agro-meteorological indicators have been frequently used to evaluate the impact of climate on crop production. In this study, we examined the temporal variations of agrometeorological indicators (growing degree days, total precipitation, dry spells and drought indices) during 1960-2014 and their impact on soybean yields in East Arkansas. Results show an increasing trend in growing degree days (GDDs) and dry spells, though the total precipitation during the soybean growing season remained nearly unchanged during the study period. Generally, GDDs and dry spells show a strong correlation with yields. We also evaluated drought variability based on different drought indices, including the Palmer Drought Severity Index (PDSI), the Standardized Precipitation Index (SPI) and the Standardized Precipitation-Evapotranspiration Index (SPEI). The drought indices are all negatively correlated to soybean yields. Overall, the one month SPEI showed the strongest impact on yields. After regression analysis, Dry spells and Total precipitation were the only significant factors in the General Linear Model (GLM).
Magugu, J. W.; Feng, S.; Huang, Q.; and Luthra, K.
"Impact of Climate Variations on Soybean Yield in Eastern Arkansas: 1960-2014,"
Journal of the Arkansas Academy of Science: Vol. 70
, Article 24.
Available at: http://scholarworks.uark.edu/jaas/vol70/iss1/24