Corn development has reached physiological maturity in many fields; it will only be a matter of days before harvest maturity is reached in the earliest planted fields.

The following dry down rates were derived from research in western Ohio, therefore they may be different for northwest IA, but they are a good baseline to work from.

• Corn will normally dry approximately 3/4 to 1 point of moisture per day during favorable drying weather (sunny and breezy) during the early warmer part of the harvest season from mid to late September
• Early to mid-October, dry-down rates will usually drop to 1/2 to 3/4% per day.
• Late October to early November, field dry-down rates will usually drop to 1/4 to 1/2% per day.
• Mid November, probably 0 to 1/4% per day. By late November, drying rates will be negligible.

Estimating dry-down rates can also be considered in terms of Growing Degree-Days (GDDs). It takes about 30 GDDs to lower grain moisture each point from 30% down to 25%. Drying from 25 to 20 percent requires about 45 GDDs per point of moisture.

On-farm storage of soybeans
Storage of soybeans on-farm requires some special considerations when compared to corn. As with most grains, when moisture is too high, spoilage and reduced germination will result. High oil content of the soybean makes them more susceptible to spoilage than corn, therefore soybeans need to be about two points dryer than corn for proper storage. For winter storage, store commercial soybeans at 13 percent moisture or less. Soybeans with less than 15 percent moisture can be dried with bin fans.

Aerate the stored soybeans to maintain grain temperature at 35 to 40 degrees F in winter and 40 to 60 degrees F in summer. Check the bins regularly for heating or spoilage.

When drying soybeans in high or low temperature dryers, be careful. Soybeans are fragile and can be damaged by air that is too hot or too dry, as well as by rough handling. Soybeans have about 25 percent less airflow resistance than shelled corn; fans sized for corn drying will produce greater airflow through soybeans. Greater airflow means faster drying.

Calibrate your yield monitor correctly
University of Nebraska Engineer Paula Jasa recommends proper calibration of yield monitors. When properly calibrated, a yield monitor can be a valuable tool to gather information about crop production, providing on-the-go estimates of yield and grain moisture content.

Jasa further explains that a yield monitor consists of several sensors and a small computer to integrate, display, and save the information. On most yield monitors, the grain flow through the combine is estimated by measuring the force the grain exerts on a sensor at the top of the clean grain elevator. The greater the grain flow, the greater the force or displacement measured. The area harvested is determined from the measured travel speed and the known width of cut. Grain moisture content is also measured so that the grain yield can be corrected to a standard moisture content and estimated on a per acre basis.

Corn stalks have feed value
Cornstalks can be a great source of winter feed for cattle, especially this year when fall pastures and stored hay are in short supply. Cornstalks that are supplemented with protein, vitamins and minerals can supply the nutritional needs of cows that are in moderately good body condition. Cornstalks are generally considered to have about 80 to 90 percent of the energy of mixed grass and legume hay per pound of dry matter, but only 20 to 30 percent as much protein. Adding soybean meal can be a good way to increase protein content. More information on the value of cornstalks can be obtained from the ISU Extension publication FM 1867