Here is a field of ultra-late soybeans planted after corn. They need to be planted as soon as they can right after corn is 
harvested, by the first week of August. These were drilled at 7.5 inch no-till drill at a high seeding rate. UGA Extension Soybean Agronomist Dr. Jared Whitaker says we need to shoot for a seeding rate of at least 175,000 seed / acre. Dr. Whitaker recommends using either a hula-hoop or a yard stick to lay out over the rows to count a 5 x 5 area for stand counts. We did a stand count this morning which showed about 180,000 plants per acre (below).
With the ultra-late system, one issue is having pods produced on lower nodes and located too low to be harvested. Irrigation and addition nitrogen help increase the height of soybean crop and potentially help increase the height of pods produced on the bottom of the plant. In any case, irrigation is a must with ultra-late soybeans. Colquitt County Ag Agent Jeremy Kichler shared this soybean irrigation chart which shoots for 45 to 50 bushel yields:
Thomas County Ag 