Maximum Yield Research

Ryan: Hi, I’m Ryan Van Roekel, PhD graduate student working with Dr. Larry Purcell on the maximum yield of soybeans. We’re here today in Newport, Arkansas to harvest one of my strip trials.
What we have here for a strip trial is essentially large scale variety trial where we have five different varieties replicated across this field. There are 12 rows of each variety and we’re harvesting them one at a time and weighing them on a weigh wagon to determine bushels per acre.
So far for the first few plots, we’ve taken out we’re in the lower 90s with one plot even topping 98 bushels per acre. We’re hoping to continue that upward trend.
Our goal for this research was 100 bushels per acre. I don’t think we’re going to average quite that high but we’re getting very close. We feel that one of the biggest limitations to our yields this year was the weather. We had very high temperatures during flowering and pod set, which may have resulted in more pods being aborted and lowering our yields.
Some of the management practices that increased our yields in this field were early planting, timely and frequent irrigation, strict pest management and choosing excellent varieties.
In addition, we’ve also applied supplement nitrogen to this field in the form of urea, being flown on late season into R5 and mid R5 and R6 growth stages.
Dr. Purcell and I believe that soybeans fixed enough nitrogen, in general to maximize yields across Arkansas. However, as yields approach an increase above 80 bushels per acre, supplemental nitrogen may be an important management factor to maximize our yields.
This research was funded by the Arkansas Soybean Promotion Board and Pioneer Hybrid and we’ll be doing this again next year. For more information and our results, log-on to Thanks.