What makes South Dakota a good place for sunflowers to grow?

South Dakota ranks 2nd in sunflower seed and sunflower oil production in the U.S.

The sunflower fields average a yield of 1,780 pounds of seed a year. Sunflowers like rain and well drained soils, but they stand up well against drought, and that's important in South Dakota. They can grow in about any soil up until June 15th, which makes them a good rotational crop for farmers. They have long roots, so even on heavily worked land, the sunflower can get to the nutrients deep in the soil profile. However for the home garden, if you want a spectacular show you've got to add organic matter to the soil.