Sunflower is considered a crop that uses soil moisture to the maximum, but it is true that the amount of available water is a limiting factor. Sunflower hybrids use soil water resources with varying efficiency, which is also greatly influenced by the number of plants sown per hectare. The use of satellite remote sensing and positioning, sensor-based measurement, GIS data analysis and processing software, and the emergence and use of technical solutions for differentiated sowing rates, open up the possibility of examining the possibility of site-specific plant density control in sunflower production. In this study, an attempt was made to determine the best sunflower plant density interval for the heterogeneous fertility zones of a given production area. The fertility zones were established using novel GIS methods. In the selected sample areas, three distinct fertility zones were defined. In each fertility zone, three plant density steps were used in four replicates. In the high and average fertility zones, increasing plant density resulted in slightly higher yields, while in the low fertility zones, sowing with reduced plant density did not cause a significant yield difference compared to the standard value. For moisture and oil content, no practical differences between plant density values could be detected.