Many AREA corn fields never experienced any tillage work last fall when wet weather set in early and kept machinery out of the field. One ISU agronomist said this may be a good year for producers to consider shifting to no-till soybeans on last year's untilled corn acres.

According to Mahdi Al-Kaisi, associate professor in agronomy at Iowa State University, the wet weather that put a damper on last fall’s harvest looks like it may have some lasting effects on 2009 spring fieldwork.

Those producers who were unable to complete the task of fall tillage may want to explore some options before trudging out into wet fields this spring trying to get their fields worked up.

One option may be to consider the use of a no-tillage system for soybeans following corn, as some research has shown benefits to planting soybeans in no-till situations.

With the exception of a few cases, Al-Kaisi said, with corn that involves a lack of drainage and wet, cold soil conditions, conventional tillage for either crop generally has shown limited advantage in yield and economic returns.

Al-Kaisi advises that as preparations for spring field operations get under way, producers need to stop and think about their tillage system choices, especially in association with conventional tillage operations which include, labor, fuel and equipment.

If producers’ ideas of primary tillage includes chisel plowing or deep ripping, Al-Kaisi said these options require 1.5 gallons of fuel per acre, or more over a no-till system; plus a secondary tillage pass with a field cultivator or disk may use 0.5 to 0.7 gallon of fuel per acre.

The fuel costs, he said, are in addition to other input costs that could possibly make no-till this spring even more appealing, especially considering the relative insignificant soybean yield differences across all tillage systems.

A long-term tillage study that began in 2002 at eight Iowa research farms evaluated the effect of five tillage systems including no-till, strip-till, chisel plow, deep-rip and moldboard plow with corn-soybean and corn-corn-soybean rotations.

He said the results of the study show no significant difference in soybean yields for the five tillage systems and two crop rotation practices.

“Most things farmers need to be concerned with for any field operation this spring are to avoid entering the field when the soil conditions are not suitable with the high potential of soil compaction due to wet soil conditions,” said Al-Kaisi.

When it comes to no-till planting of soybeans after corn, Al-Kaisi recommends planting directly in standing stalks.

“As for chopping residue, the answer is ‘no,'” said Al-Kaisi. “It is a bad idea. They should plant in standing corn stalks.

“Chopping residue is a bad idea because the stalks will lose (their) effectiveness in preventing soil erosion under the heavy rain (if) chopped.”

Some challenges may exist in managing corn residue, Al-Kaisi said, but simple modification of the planter to include residue cleaners, heavier down-pressure springs or other residue management attachments are far more cost effective than the expense associated with conventional tillage.

You can contact Kriss Nelson by e-mail at jknelson@frontiernet.net.