6.3 Managing the Crop

Use soil test results to determine both lime and fertilizer requirements (see Table 6.3.1). Soybeans have the ability to fix nitrogen and, under optimal growing conditions, do not require nitrogen fertilizer. If used, band-placed fertilizer should be at least 2 inches to the side and 2 inches below the seed. Do not place any fertilizer in contact with the soybean seed. Diammonium phosphates or urea should not be used in the fertilizer band. Do not use more than 40 pounds of potassium in the fertilizer band at planting either.

The most frequent cause of disappointing soybean yields is drought in the month of August, when seeds within the pods are enlarging and filling. The crop is actually fairly drought resistant before that, but moisture stress in August causes pods to shed and seeds to abort. For this reason, it is recommended that soybeans not be grown on sandy or gravelly soils.

Lodging before harvest is commonly encountered, but modern combines are designed to handle lodged soybeans. At maturity, leaves have been shed and only stems and pods must be passed through the machine. Soybeans store safely at 14 percent moisture. They crack or break if handled roughly, especially when they are very dry, as they usually are when in storage during the coldest months.