For almost a month, the weather was warm and dry this fall, creating ideal harvesting conditions for Iowa, before rain showers greeted most of the state over the weekend of October 23-24. Rains helped alleviate dusty and overly dry conditions that have allowed field fires and some harvesting equipment fires to break out. Aside from the first widespread measurable rainfall in weeks, last week continued the pattern of temperatures above 70-degrees F during the day, with overnight lows dropping into the 30s.
"As we approach the end of October, few acres remain for Iowa farmers to harvest," says Greg Thessen, who heads the Iowa office of USDA's National Ag Statistics Service in Des Moines. "Favorable weather has enabled growers to continue harvest without any delays. This has put Iowa's harvest a month ahead of last year's pace and given farmers plenty of time for fall fieldwork."
The weekly weather and crop conditions survey released October 25 indicates that farmers are focusing on tillage of compacted areas of fields such as end rows, as well as drowned out spots, while waiting for cooler weather before they start applying anhydrous ammonia.
Moisture content of corn still standing in fields estimated at 15%
There were 6.4 days suitable for fieldwork last week, just below the 6.9 recorded the previous two weeks. For the fourth consecutive week, Iowa reported more than 6.0 days suitable with West Central Iowa reporting the highest number of days, at 6.8 days suitable. The statewide survey released October 25 shows topsoil moisture rates 8% very short, 27% short, 63% adequate and 2% surplus. Subsoil moisture rates 4% very short, 18% short, 72% adequate and 6% surplus.
The survey shows 86% of the corn acres have been harvested, 35 days ahead of last year and 25 days ahead of the 5-year average and the furthest corn harvest has been by October 24 since 2000 when 92% of the corn acres had been harvested. Moisture content of all corn remaining in the field is estimated at 15%, while the moisture content of corn being harvested is estimated at 14%.
Soybean acres harvested are 97% complete, 24 days ahead of last year and 19 days ahead of the 5-year average and the furthest soybean harvest has been by October 24 since 2005 when 97% of the acres had been harvested. Grain movement is reported at 20% none, 22% light, 36% moderate and 22% heavy. On-farm storage availability rates 20% short, 73% adequate and 7% surplus while off-farm storage availability rated 18% short, 72% adequate, 10% surplus.
Livestock now being turned out into stubble fields for grazing
Pasture and range condition rate 5% very poor, 12% poor, 31% fair, 42% good and 10% excellent. Hay and roughage availability is currently rated 11% short, 73% adequate and 16% surplus. Quality of hay and roughage is currently rated 11% poor, 53% fair and 36% good. Livestock are now being rotated to stubble fields for grazing, as pastures have been grazed down. Feeder calves are beginning to go on feed or being sold to feedlot operations.
Think twice before doing fall tillage of soybean stubble
"The past few weeks have been absolutely beautiful to harvest soybeans and corn, and to do tillage work," comments John Holmes, Iowa State University Extension field agronomist in north central Iowa. "Farmers in nearly all of north central Iowa are finishing combining and are now tilling cornstalks. It's also fairly common to see soybean stubble that's been tilled. Yields have been quite variable this fall. Farmers in Hardin, Story, Hamilton, Worth, and Cerro Gordo are reporting excellent yields while those in Wright and parts of Humboldt and Franklin County report disappointing yields. They had hail in late May and early June, and then heavy rains during May, June, and July."
Holmes saw two disturbing trends in his travels across his territory this past week. They are fall tillage of soybean fields and hog or poultry manure being applied now. Farmers tell him they are tilling soybean stubble to reduce soil compaction and to work the soybean straw into the soil. Some report problems getting the soybean straw through field cultivators in the spring so they want to bury some of it now, in the fall. "Both reasons are good ones," says Holmes. "But don't forget that tilled soybean stubble has a tendency to blow next spring and it's very susceptible to water erosion. Also, don't forget that soil compaction is often corrected by freezing and thawing in late winter."
Wait for soils to cool to 50-degrees or below before applying N
Farmers are emptying manure from pits under hog buildings because it needs to be done. That's understandable. The large poultry buildings are also emptying their manure storage. "However, keep in mind that a portion of the nitrogen in liquid hog manure or in the poultry litter behaves just like anhydrous ammonia in the soil," Holmes points out. "It starts converting to nitrate soon after application. ISU Extension agronomists recommend waiting until soils cool to 50-degrees F and are staying in a downward cooling trend before you begin applying manure or anhydrous ammonia. The nitrate form of nitrogen can leach from the soil or be lost to denitrification if soils become waterlogged."
"This has been a great fall harvest season and most of us are starting to wind down," notes Holmes. "As you look back at 2010 take a couple minutes and think about what worked well for you. Also, were there some things you could have done better in managing your 2010 crops? Don't forget that ISU Extension has resources and information to help crop producers. Stop by and visit with your local Corn and Soybean Initiative partner, or talk to your ISU Extension field agronomist if you have questions. We're happy to visit with you about the past growing season and look forward to helping you plan for the upcoming one."