
Sunflower Stalks Trap More SnowBy Don Comis March 29, 1999When fierce 30-mile-per-hour-plus
winds swept across some research fields in Akron, Colo., this winter, they hit
a 2-1/2 foot high "wall" of sunflower stalks left after last fall's
harvest. That wall kept soil from blowing away. Had it not been an unusually dry winter in Akron, that wind would have
carried snow--and that wall would have trapped 3 to 10 times more snow than
would normally accumulate. Agronomist David C. Nielsen with the Agricultural Research Service in Akron
found that 2-1/2 feet is the height needed to trap enough snow to add 3 to 9
more inches of soil water. This makes up for soil water used by the sunflower
crop and makes sunflowers a worthwhile alternative to wheat in the arid Great
Plains. There, average precipitation is only 16.5 inches a year. Rain is so scarce
that most farmers traditionally have dared plant a crop only every other year,
leaving the ground bare or fallow for a year to save up enough soil water for a
crop. But through research such as Nielsen's, farmers increasingly plant crops two
or three years in a row--and make more cash. And since rains don't fall to suit
farmers' timetables, planting an additional crop like sunflowers gives them a
better chance to get the timing right for at least one crop. Leaving stalks or other plant residues on the ground after harvest is what
makes the annual crops possible. The residue provides a soil mulch that reduces
evaporation, stores water for the next crop and fights wind erosion, according
to Nielsen, with ARS' Central
Great Plains Research Station. The ARS scientists have found that sunflower yields are best when the crop
is rotated in every fourth year. The usual rotation is
wheat-millet-sunflower-fallow. This gives time for sunflower diseases and other
pests to die out. Scientific contact: David C.
Nielsen, ARS Central Great Plains Research Station, Akron, CO 80720, phone
(970) 345-0507, fax (970) 345-2088,
[email protected].
U.S. Department of Agriculture | |