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Crops in the Southern United States are generally produced in fields which are known to have a high degree of variability in soil type, topography, water holding capacity and other major factors which affect crop production. Therefore, conventional, uniform-rate overhead irrigation systems tend to over-apply or under-apply water to the crop. A variable-rate lateral irrigation system was developed for site-specific application of water to match crop needs. This system is able to monitor and apply water based on the actual soil moisture content, pan evaporation data, or the U.S. Climate Reference Network (CRN) data. Information from the moisture sensors, evaporation pan and CRN is acquired using wireless technology. A GPS receiver is used to determine the position of the lateral irrigation system in the field. A variable speed control system allows the irrigation system to move quickly over wet spots and slow down over dry spots. The lateral irrigation system is controlled by the nozzle-pulsing technique for variable-rate water application. The nozzle pulsing technique to adjust irrigation rate worked very well. The average water application rate error was less than 2%. There was a strong correlation between soil electrical conductivity (EC) and soil water holding capacity. Therefore, the EC measurements could be used for irrigation scheduling decisions.