The researchers say 8 percent moisture content is ideal for efficient dehulling with minimal groat breakage. ARS researchers monitored velvetleaf weed seed production and corn yields in fields planted at 1, 1.5 and 2 times the normal rate over a 3-year period. A separate study showed that an 80 percent reduction of velvetleaf weed seeds translates into a 12 percent increase in annual farm profits. Such a reduction also eliminates herbicides in one of every four years. Denser corn growth helps the crop plants form a tighter canopy, blocking weeds from sunlight needed to produce seeds.
Dense planting can backfire, however, as the strategy requires greater soil moisture.
Yields dropped one season at the 1.5 seeding rate and two seasons at the double rate because of dry spells. Improved corn varieties may make higher rates feasible in the future. The ARS scientists bred the new strain from the bacterial species Bradyrhizobium japonicum . Soybeans harbor soil bacteria on their roots that take nitrogen from the air and convert to a form plants can use as fertilizer. This means less artificial fertilizer is needed.