Farm News, IA
04-19-07
April weather delays planting progress
By Kristin Danley-Greiner, Farm News staff
AMES — In past years, some farmers hit the fields as soon as the weather
turned favorable in March. But with the on again, off again cold snaps Iowa has
seen lately, producers can still successfully plant their corn into May.
Roger Elmore, corn specialist with Iowa State University Extension, along
with Lori Abendroth at ISU, have been reassuring producers that the rain and
snow blanketing the state April 10-11, coupled with the prior week’s cold and wet
weather, should not be too worrisome.
While the possibility of delayed planting is a “legitimate” concern,î Elmore said,
especially since Iowans intend to plant 10 percent more corn this year and corn
plantings dates in Iowa have become steadily earlier the past three decades,
optimum yields can still be obtained between April 15 and May 15.
According to research documented at the university, using a conservative
estimate, yields decreased approximately 0.75 percent per day after the optimum
planting period of April 15 and May 15.
“At a yield level of 180 bushels per acre, that is equivalent to a 1 1/3-bushelyield-reduction per day. The percent loss value is an estimate, and will vary
based on location, year, etc. If planting starts during the week of April 23 and
proceeds at a pace similar to that of 2006, then 80 percent of Iowa’s corn should
be planted by mid May, thereby realizing full yield potential,î” Elmore said.
Keep in mind that, in general, corn should be planted when soil temperatures are
near 50 degrees Fahrenheit. Seed will absorb about 30 percent of its weight in
water, and temperature does not affect water inhibition much.
In cold soil conditions (below 50 degrees Fahrenheit), seeds will readily absorb
water but not initiate root or shoot growth; this leads to seed rots and poor
emergence if poor seedbed conditions are prolonged. Recommendations are to
begin planting when soils are near 50 degrees Fahrenheit or are quickly
increasing to that level.
With ground temperatures in the upper 50s this week, southwestern Iowa farmer
Darrell McAlexander began planting Monday. He said he was satisfied with the
weather lately and decided to start. His goal is to be done planting by May 10
and has increased his corn acres by 10 percent.
“I’d say I’ve got five to 10 percent in the ground now,î” he said Tuesday. “I’m very
comfortable with planting right now. I’d say we’re good to go.”î
Elmore cautioned that “muddingî” in corn will decrease yield potential not only in
the short term through reducing plant stands and resulting in more variable plant
emergence rates, but also can have long-term impacts such as poor root
development ensuing from soil compaction.
“The long-term impacts from soil compaction can plague growers for years,”î he
said.
In McAlexander’s area of Sydney, the topsoil is dry, but the subsoil moisture
levels are adequate.î He’s planting his corn in soybean stubble, employing no-till
techniques.
“We had a few snow flurries last week, but nothing accumulated,î” he said. “We
did have some freezing temperatures and the low was 20 degrees, but I decided
that we were fine, especially with the leaves starting to come back out on the
trees.Ӕ
Secondly, most seed companies have reported that the more popular hybrids
have been sold out for a while. So if large areas of corn need to be replanted this
year, those supplies will be limited if available at all, Elmore said. McAlexander
planned ahead and has all the seed he needs, he said, even with the increase in
corn acreage on his farm.
“The best plan is to keep the seed in the bag and the planter in the shed until
seedbed conditions are conducive for planting corn,î” Elmore said.