Making the Grade

Making the Grade

By: Jason Jenkins, Mill Creek Communications

The steady grind of steel on steel fills the evening air as a Kansas City Southern freight train comes to a lumbering stop at Central Missouri AGRIService’s shuttle-loader facility on the outskirts of Marshall. It’s 2 a.m. on a summer Saturday, and during the next eight to 10 hours, nearly 420,000 bushels of Missouri-grown soybeans destined for export will be loaded into 110 railcars.

The shuttle-loader is extremely efficient. It can fill a railcar with nearly 3,800 bushels in roughly 4 minutes. Just as efficient are the Missouri Department of Agriculture’s licensed grain inspectors, who can grade the quality of that grain before it’s time to fill the next car.

“Grain inspection definitely isn’t a 9-to-5, Monday through Friday kind of job,” says Jimmy Williams, program administrator for Missouri Grain Inspection Services. “Our inspectors are required to provide service to grain elevators any time, seven days a week, 24 hours day. We have 10 shuttle-loading facilities across the state, and when those trains arrive, whether day or night, weekend or holiday, it doesn’t matter. We’re expected to be there. Fortunately, we have a very dedicated team.”

Williams says that in any given year, the program’s staff of just 35 full-time grain inspectors grades the contents of nearly 2,000 barges, more than 4,000 shipping containers and 40,000 railcars. While the vast majority of those shipments contain corn and soybeans, other crops such as wheat, rice, oats and sorghum are also inspected.

“Typically, grain is officially inspected when either the buyer has requested it or when it’s a shipment headed for export. Those shipments are mandated to be inspected,” he says, noting that soybeans make up the largest volume of officially inspected grain in the Show-Me State. “We inspect grain on behalf of USDA and adhere to federal standards, and it’s those high standards that help ensure that buyers receive what they’re paying for.”

American producers have provided the world with safe, abundant and high-quality grains and oilseeds by following guidelines outlined in the U.S. Grain Standards Act for more than a century. Missouri’s soybean growers can maintain and even enhance the value of their crop by eliminating elements that reduce quality. At harvest, this includes weed seeds that find their way into thecombine’s grain tank.

Soybean Grading 101
Soybeans that are officially inspected receive one of five grades: U.S. No. 1, U.S. No. 2, U.S. No. 3, U.S. No. 4 or U.S. Sample Grade. Where the commodity falls along this spectrum is determined by a set of five factors that are assessed during the inspection process, which begins by taking a sample.

Doug Riley, quality assurance specialist with the Missouri Department of Agriculture, evaulates a soybean sample.

“The grading process is only as good as the sample taken,” says Doug Riley, quality assurance specialist with the Missouri Department of Agriculture and a licensed grain inspector based in the Marshall field office. “We want to make sure that the sample is representative of the entire railcar or barge or whatever we’re sampling from.”

Hand probes, mechanical probes, Pelican grain samplers and truck tailgate samplers are all approved sampling devices. For soybeans, as well as corn, a sample of 1,000 grams is required.

“They’ll load a railcar with 225,000 pounds of soybeans, and we need just 2.2 pounds to grade it,” Riley adds. “The system is pretty efficient.”

To begin grading a soybean sample, the inspector first passes it through a rotary divider. This device partitions the grain while maintaining the representativeness of the original sample, leaving the inspector with a work portion and a file sample, which is stored at the inspection office should retesting be requested.

The inspector takes the work portion of the sample and determines its moisture content. Test weight is evaluated next.

The beans are placed in a small hopper, and a quart cup is placed below. When the hopper valve is opened, grain flows into the quart cup, overflowing it. The inspector uses a striker to level the grain in the cup, which is then placed on the test weight scale to measure pounds per bushel.

“Moisture content and test weight are inversely related,” Williams explains. “The higher the moisture, the lower the test weight. While neither measure is a grading factor, both are essential to the soybean’s storability and overall value.”

The inspector’s next step is evaluating the sample for foreign material, which is anything other than soybeans. The work portion is first hand-picked for coarse foreign material. This includes whole kernels of corn, cockleburs, sticks, soybean pods or other material larger than a soybean.

Once coarse foreign material is removed, the cleaned sample is cut down to 125 grams using a Boerner divider, then placed in a 10/64-by-3/4-inch oblong-hole sieve pan atop a 1/8-inch round-hole sieve pan and shaken five times. Whole soybeans remain in the oblong-hole sieve; most split soybeans fall into the round-hole sieve. The majority of fine foreign material, including weed seeds, finds its way into the bottom pan. The inspector’s trained eyes now get put to the test.

The inspector sits at a desk with a top of a specific off-white color. The lights above, which are required to be in a precise range of brightness, now illuminate the task at hand: analyzing the soybeans for damage.

The causes of damage in soybeans are many. They include green damage, weather damage, heat damage, frost damage, mold damage, sprout damage and various types of insect damage. Discolored or stained soybeans are also separated.

“You can’t mistake ugly for damage,” Riley says with a laugh. “Beans that are immature, we call those wafers, are still considered sound as long as there’s some meat on the inside.”

Once the analysis is complete, the soybean’s grade is determined by calculating the total percent of damaged beans as well as the percent of heat- damaged beans, along with foreign material, splits and soybeans of other colors.

Maintain Your Grade
Factors that impact the grade occur at various stages along the crop production cycle. While some in-field damage during the growing season can’t be remedied, producers can take steps to ensure the best beans at harvest and during storage.

While test weight isn’t a factor in grading soybeans, it is part of the analysis because of its role in storage for the crop.

“Soybeans can have up to 1 percent foreign material and still be graded as a U.S. No. 1 yellow soybean, but anything over that, the grade falls to a No. 2,” Williams says. “Producers and elevators alike are paid more for No. 1 beans than No. 2, so it’s a big deal. One way to help ensure you keep a No. 1 grade is to reduce weed seeds.”

According to the USDA, 80 percent of all intercepted weed seed in soybeans comes from four types: rag weed, cocklebur, Johnson grass and pigweed, which in Missouri would include waterhemp and Palmer amaranth. To minimize weed seed and other foreign material in harvested soybeans, the USDA recommends that producers adjust combine cutting heights and other settings; clean out their combines regularly to prevent both weed spread and cross-crop contamination; and avoid harvesting weeds when possible. It’s also recommended that bins and conveyances are cleaned regularly and that soybeans with low foreign material are segregated from those with higher volumes.

At a time when commodity prices are low and margins are razor-thin, paying attention to the details can potentially have a large impact on the bottom line.

“Based on my experience with Missouri Grain Inspection Services during the past 10 years, most of the grain we inspect is very good quality,” Williams says. “Most is No. 1 or No. 2, so I think that speaks well for Missouri farmers.”

Editor’s Note: This is the fifth article in a yearlong series examining the past, present and future of weed control in the production of soybeans in the Show-Me State. In this issue, we take a look at the impact weeds can have on grain quality. Additional photo courtesy of Missouri Department of Agriculture. To learn more about Missouri Grain Inspection Services, visit Find the entire October issue here.