Double crop soybeans in Kentucky tend to be shorter than plants from full season plantings. Since lowest pod height is related to plant height, double crop soybeans may be subject to greater harvest losses due to pods remaining below the level at which the combine header is operated. While it would be possible to lower the header closer to the soil to pick up some of those pods, that would slow down harvest and increase the risk of picking up stones and other trash. Although the actual cutting heights used in Kentucky are not known, some producers use combines with flexible "ground-hugging" headers, and others use nonflexible headers. Regardless of header type, some producers cut higher to avoid stones or to complete harvest more quickly.
Grabau, Larry J. and Pfeiffer, Todd W., "Stubble Losses of Kentucky Soybeans" (1989). Agronomy Notes. 62.