Monitoring Compositional Quality

If you grow soybeans you are selling pounds of oil and pounds of protein, not bushels. End users buy either oil, protein or the leftover hulls.

A 60-pound bushel of soybeans contains about 11 pounds of oil, 44 pounds of meal, 3.5 pounds of hulls and 1.5 pounds of moisture.

While growers sell soybeans to elevators, these soybeans are ultimately bought by processors (crush plants) who sell oil, meal and hulls to buyers. Processors make their money on the pounds of oil in a bushel and percent of crude protein in the meal; the more of each, the better for their bottom lines.

Processors and end users are concerned because the soybeans and meal they buy today aren’t as good as they were 10, 15 or even 20 years ago. Aggregate U.S. oil and protein levels have been slowing trending downward over the last couple decades. Some of this decline is due to the expansion of soybean production to the Dakotas and Western Minnesota, which have cooler climates and lower quality. And some of the decline is due to seed companies focusing on yield and not on output composition in their varieties. Oil has declined about 1 point in general, while protein has declined 2 to 4 points over that time. The decline is much greater in the Western Corn Belt than the Eastern, while the Delta and Southeast tend to maintain their levels.

Our family has a farm in Nebraska and we submit one or two soybean samples for analysis every fall and by the end of the year we get back a card for each entry submitted. In 2017 the soybeans submitted came from one field planted to Asgrow 2733. Crude protein was 32.9 percent, oil was 18.9 percent and contained a combination of five essential amino acids (lysine, cysteine, methionine, threonine and tryptophan) important in animal diets.

The 2017 Western Corn Belt and U.S. averages for protein were 34 percent and 34.1 percent; oil 19 percent and 19.1 percent; and essential amino acids 15.2 percent and 15.1 percent, respectively. As you can see, oil and amino acids levels for our soybean sample were comparable to the Western Corn Belt and U.S. average, but protein was a point lower. That was not a surprise as I have been tracking oil and protein levels on our farm for over a decade now and protein is always low, but oil is always near 19 percent.

What the soybean industry wants is a soybean that produces a minimum of 19 percent oil and 35 percent crude protein (at 13 percent grain moisture), sometimes referred to as the 19/35 initiative. Crushers are okay with 19 percent oil and recognize that the meal they produce should have a minimum spec of 47.5 percent crude protein. However, it takes a bean with 35 to 35.5 percent protein to produce meal with that level of protein. Unfortunately, growers are producing beans with oil near the 19 percent mark and less than 35 percent crude protein.

What can you do about it? Like me, you can collect a sample or two during harvest and track the oil and protein levels in your soybeans to see how they are performing relative to the Illinois and U.S. averages. Baseline your results and try to select varieties based not only on yield and agronomic characteristics, but also oil and protein levels. As with all traits, oil and protein levels in the seed vary considerably across varieties.

Soybean agronomist Daniel Davidson, Ph.D. posts blogs on agronomy-related topics. Feel free to contact him at djdavidson@agwrite.com or ring him at 402-649-5919.