May 1, 2008
Rains Continue Slow Spring Season For Local Farmers
Rain, rain go away, and come back some other day. With another week of little if any fieldwork getting done by area farmers, Mother Nature is seeing the finger pointed her way as rains again soaked much of Missouri.
According to the Missouri Agriculture Statistics Service (MASS), farmers in northeast Missouri reported ˝ day of field work time last week. That was due to another 0.8 inches of rainfall recorded in Scotland County, falling throughout the week, insuring that topsoil moisture levels remained high.
Through April 27th, Scotland County had recorded 4.57 inches of rain according to MASS. Those totals were below the state average of 6.83 inches, but still farmers saw their progress stalled like their counterparts across the state.
With 70 percent of local ground rated as retaining surplus topsoil moisture, little progress was made on the farm. Northeast Missouri still has just 14% of its ground worked for spring tillage, with only 2% of the projected corn crop planted. That compares to 38% of ground worked at this time last year and more than 18% of the corn already planted.
Last year was a little wetter than normal across Missouri meaning the one-year comparison falls even further when looking at the state averages. This year 24% of the ground in the state has been worked with only 8% of the state’s corn crop planted. Missouri had 62% of ground tilled last year at the end of April and 43% of corn planted. That was still below the state average of 73% of ground worked and 66% of corn planted.
Rain-delayed planting is no reason to switch from corn to soybeans or to switch to an early-maturing corn variety, said a University of Missouri Extension agronomist.
Yields usually begin to drop on corn planted after May 10 in central and northern Missouri. Continued rains and cool soil temperatures kept farmers from planting their corn fields at usual times in mid-April.
“I would stick with corn through the end of May,” said Bill Wiebold, corn and soybean specialist. “With the high price of corn, there is financial incentive to stick with corn even with some yield loss.”
Growers have to make individual decisions for their farms, Wiebold said during a weekly teleconference with MU Extension regional agronomists. “Even if you incur a 5-percent yield loss after May 10, it doesn’t make economic sense to try to find soybean seed and make the switch.”
Rains coming every other day haven’t made planting decisions simple for crop farmers this year, Wiebold said. He cautioned against rushing into the field before the ground is ready to work. Planting in wet fields can cause soil compaction and form clods that will hamper crop growth.
“Planting when soils are wet can compact the planter slot sidewalls. That compaction increases root damage and restricts where roots can grow,” Wiebold said. “The corn may come up and look fine until dry weather hits. Then there won’t be enough roots to supply water to the plant.
“Rain is our major concern now. Soil temperatures, which should be above 55 degrees at the two-inch depth, are safe for planting now. If they are not warm enough, they will be in a few days.”
Switching to an early-maturing variety almost assures yield loss. “Those early varieties are shorter and have less yield potential,” he said. “An early variety might offer some advantage in reduced drying time at harvest, but that depends on the fall season.”
Anyone switching from a 110-day variety to a 100-day variety should increase seeding rates by up to 4,000 seeds per acre to offset potential loss.
Delayed planting increases the risk from drought damage at the time of pollination. The later a corn plant matures, the higher the chance of pollen drop coming in hot, dry weather, which reduces the kernel set on the corn cob.
In four years of planting-date studies at the MU Bradford Farm in Columbia, Wiebold found that corn yields begin to drop after the first week of May. By May 20, yields dropped an average of 16 percent compared with the earliest planting date over the four-period. By June 4, yields dropped 24 percent.
“So much depends on the weather in late June,” Wiebold said. “We’ve had late plantings when rain and cooler temperatures occurred at pollination. Excellent yields resulted in those years.”
With normal rainfall or irrigation, yield loss is minimal through at least mid-May planting dates.
Corn seed should be planted between 1.5 and 2 inches deep in the soil, Wiebold said. That allows for good root development, which helps later in a dry season. “In general, Missouri farmers plant too shallow,” he added.
“For now, wetness is our problem,” Wiebold said. “We need a week of good drying weather.”