Soybean harvest is just beginning in Kansas. It is a good idea for producers to keep in mind the Kansas Soybean Yield and Value contest as they fire up the combines.
Each year the Kansas Soybean Association, with help from K-State Research and Extension, and sponsorship from the Kansas Soybean Commission, conducts the Kansas Soybean Yield and Value Contest. The contest is a fun way for producers to showcase their high yielding and high quality soybean with other growers in Kansas and to provide information on what production practices they did to achieve those excellent yields. In addition to grower recognition, cash prizes are awarded to the 1st, 2nd, and 3rd place winners for the 9 districts across Kansas and the top three finishers in the quality contest. Contest rules and entry forms are found online at: http://kansassoybeans.org/association/contests/
The yield contest first began in the early 1980’s but more detailed historical data began in the early 2000’s. When growers submit entry forms for the contest, they are asked to share some of their production practices that they used on the soybean crop. Using this information, we can identify shifts in producer practices over the last two decades from high yielding soybean growers.
When comparing yields over the last 20 years, state soybean yields have improved almost 8 bushels per acre (bu/acre) while contest entrants have gained nearly double that (15 bu/acre) in the same span of time (Figure 1). This indicates that soybeans are a crop that can be managed for higher yield when proper high yield practices are adopted. The 2017 state-average yield was 37.5 bu/acre versus average yield contest of 79 bu/acre, with an average yield gap between high yield and state-average close to 42 bu/acre, previous year gap was 37 bu/acre.
Figure 1. Difference in yield between state-average as reported by Kansas Ag Statistics and the entries in the Kansas Soybean Yield Contest from 1996 to 2016.
A few soybean production practices have changed over time as well. Over the last decade, producers in the soybean yield contest have moved to a lower seeding rate (Figure 2). In 2001, seeding rate averaged just over 165,000 seeds per acre while recently, seeding rates dropped below 150,000 seeds per acre, with an estimated annual rate of seeding rate drop of 1044 seeds/acre per year since 2000 (Figure 2). This may be a function of seed prices increasing over time and producers have more confidence in final plant stand with improved planting equipment and seed treatments. In addition to seeding rate changes, soybean row spacing has also seen a decline over time with narrower rows (<30 in) being adopted more by growers in the Kansas Soybean Yield Contest (Figure 3). This decline is likely due to reduction in use of drills and the increase use of planters to sow soybean.
Figure 2. Seeding rate of contestants in the Kansas Soybean Yield Contest from 2001 to 2017.
Figure 3. Row spacing of Kansas Soybean Yield Contest entrants from 2001 to 2017. Narrow rows were any spacing 10-in or less. Wide rows were any spacing 30-in or greater. Mid-rows were any spacing between 10- and 30-inch.
Since 2004, Kansas soybean producers have had the opportunity to enter their soybeans into the Value Contest. With this information, the contest is able to showcase the true end-use value of soybeans including protein, oil, and other value added products.
With many field crops, a relationship exists between yield and protein where protein decreases as yield increases. However, in the case of the Kansas soybean yield contest, there does not appear to be a strong relationship in protein (slight negative relationship) nor in oil (slight positive relationship) relative to yield (Figure 4).
Figure 4. Relationship between soybean oil and protein vs. soybean yield for 100 entries in the Kansas Soybean Value Contest, more than 10 years data.
If a producer has interest in submitting an entry in the Kansas Soybean Yield Contest, they need:
The Soybean Yield and Value Contest is free to producers. One does not have to enter the Yield contest to enter the Soybean Value Contest, just fill out the entry form and mail a 20-ounce soybean sample to the Kansas Soybean Office by December 1, 2018. The contest winners will be announced at the Kansas Soybean Expo on January 9, 2019 in Topeka. To find complete rules and the entry form, visit http://kansassoybeans.org/association/contests/
Doug Shoup, Former K-State Extension Specialist
Ignacio A. Ciampitti, Crop Production and Cropping Systems Specialist