Sorghum can be harvested at 25 to 30 percent moisture for storage as high-moisture grain; however, harvest losses due to unthreshed heads are likely to be higher. Kernels are more likely to be damaged at higher moisture contents, although this is not a concern when grain is to be fed on the farm.
Ideally, sorghum to be marketed should be harvested with a grain combine when grain moisture is 20 percent or less. In many cases, a frost is necessary to reduce grain moisture to this level. Harvest losses for sorghum usually are higher than for corn and may average 5 to 10 percent. If harvest losses are above 10 percent, check the combine adjustment. Seventeen kernels per square foot is a loss of approximately one bushel per acre. Do not delay harvest much beyond the first hard frost because the potential for deer and bird damage increases dramatically.
Plan on drying grain most years. Store grain at 13.5 percent moisture. Drying and cooling rates for sorghum are only about two-thirds those of corn since the sorghum grain packs together more than corn, resulting in less air space in the grain mass and more resistance to airflow. Do not increase the heat level to speed up drying. Drying air temperatures for sorghum and corn are essentially the same.
Grain sorghum also can be harvested as silage. Grain sorghum makes an excellent silage, comparable in quality to corn and slightly better than forage sorghum silage. Harvest at the soft to medium dough stage. A reasonable yield goal for grain sorghum types is 10 to 15 tons per acre. Higher yields can be obtained with forage sorghums, but energy content of the silage can be lower. Sorghum heads also can be chopped and ensiled to produce a silage similar to ground ear corn in composition and value.