Using Southern Oscillation Information for Determining Corn and Sorghum Profit-Maximizing Input Levels in East-Central Texas

Research into Southern Oscillation (SO) phenomena and related sea surface temperature is providing promising results concerning the ability to improve long-range climate forecasts. This study asks whether SO event information would be of value to Texas corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench] producers. Simple ordinary least squares regressions suggest that an El Niño Southern Oscillation (ENSO) event increases preseason rainfall by approximately 3 in., whereas, a cold SO event decreases rainfall by 4 in. These extreme phases appeared to have no impact on growing season precipitation. Economic results indicate that SO information is more valuable for corn than sorghum producers. The value of SO information ranged from $1 to $2/acre for corn production, depending on price. For sorghum, use of SO information had no value. Research QuestionThe objective of this study was to determine whether producers could use knowledge of the Southern Oscillation (SO) phases in their planning and production decisionmaking. Literature SummarySouthern Oscillation events can be divided into two categories: El Niño Southern Oscillation (ENSO) and cold events. For the study area, an ENSO event is associated with cooler and wetter weather, whereas, a cold event is associated with warmer and drier weather. Typically, SO events are identified early in the calendar year and persist for several months. Several studies have concluded that there is a relationship between the SO and crop yields. Unfortunately, few studies have addressed whether farmers could use knowledge of the SO events in their management decisions. Study DescriptionExperimental data from two locations were used to estimate a corn production function, whereas, data from only one of the locations was available to estimate a sorghum production function. The two study sites were the Brazos River Bottom Research Farm, located 8 mi west of College Station, TX and the Stiles Foundation Farm, located near Thrall, TX approximately 50 mi west of College Station. The corn data set contained 1098 observations covering the years 1984 to 1988 and 1990 to 1993. The sorghum data set contained 571 observations covering the years from 1984 to 1992. Applied QuestionsDoes the probability distribution for rainfall vary in the study area by SO phases? An ENSO event appeared to increase preseason rainfall by approximately 3 in., whereas, a cold event decreased rainfall by 4 in. The extreme phases of the SO appeared to have little impact on early and late growing season rainfall levels. Tests for significant differences between the variances for the various rainfall periods and SO phases revealed no significant differences at the 5% level. Does use of SO events information have economic value? For corn production, it appeared the use of SO event information allows the producer to alter input usage. The value of the use of SO information ranged from $1/acre to over $2/acre depending on corn price. For sorghum, it appeared knowledge of the SO provides little additional information in terms of N applications.