SOYBEAN POPULATION STUDY

Conducted by Northwast Ag Consulting
Dan Steiner & Ben Pinkelman
(This was a three year study, funded by the Nebraska Soybean Checkoff.)


This three year project was completed the fall of 2008. The following information of data show that populations can safely be lowered and these studies will show producers that soybean price and soybean seed price both influence the most economical planting rate.
Click here to see "Three Year Combined Results"



Lower seed prices and higher soybean prices mean planting thicker would make sense but when the opposite occurs, lower populations give the most profitability.
The full yield results are attached. Statistically, two locations had differences this year. In both instances the 80,000 was the one that was off. The other four also showed that the 80,000 planting rate was too low to maximize soybean yield and profitability. For the various farming systems used, the soybean yields followed a surprising similar trend over different populations. With the price of soybean seed continuing to rise and the soybean price decreasing, 100,000 showed the most profitability over all the locations.


Questions and Answers about Soybean Population
The main objective of this study was to answer producers' questions about what soybean population should be planted. The goal was to minimize seed expense while keeping the most profitable yield. Another objective was to show field condition research to producers. Yield mapping software was utilized in data analysis, so another goal was to show how the new technology can be used for field research. One indirect goal was to see what yields levels are possible at lower populations to help make replant decisions due to hail, emergence issues, etc.


Check out the Six Population Studies Conducted in Nebraska
Six population studies were planted and all made it to harvest without any major incident. Planting took place around the middle of May 2008 for all the plots which was when the majority of beans went in around the area. The varieties used were common to the area and were average for height and bushiness. Seed treatments were used on some locations depending on the farmer's program and these are noted in the data. All locations were planted with 30 inch corn planters this year 2008). Emergence were aided by irrigation in a couple locations or rainfall in the others. Throughout the summer, the 80,000 blocks looked too thin but they yielded well in the end. Weed control did not suffer in the thinner blocks and canopy closure occurred at similar times. Two locations received Headline fungicide and the thinner populations stayed greener and held their leaves longer.


Combining occurred between early October and early November. No issues arose due to combining time.


This study was paid for with your checkoff dollars.