Research Accomplishment Reports 2011

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Determining Impact of Lower Soybean Plant Populations on Other Practices within the Soybean Production System

C. Lee
Department of Plant and Soil Sciences

 

Non-Technical Summary

$28 to $32/acre, depending on soybean seed size and seeding rate. If additional data supports the initial findings, then farmers could save a significant amount of money. The purpose of this project is to determine if lower soybean populations can produce high yields while reducing input costs.

2011 Project Description

Additional research was conducted in 2011 to compare soybean yields to plant populations. This research was leveraged with funding from the United Soybean Board, a checkoff program of American soybean producers.

In 2011, final populations near 100,000 plants per acre were adequate to achieve optimum yields. Optimum yield is defined as the economic optimum. However, research on high inputs indicates that yields can be increased at final populations closer to 200,000 plants per acre. Unfortunately, in that study, we only compared two populations.

In 2012, we intend to include more populations and try to get a response curve. When that is accomplished, we intend to compare economics to determine if optimum yields require more plants under high input systems.

2011 Impact

The funding from the United Soybean Board is helping five graduate students at several institutions complete their degrees. Publications will result from their efforts over the 2012 calendar year. The Hatch component in Kentucky was helpful for us to work with producers in Kentucky on maximum populations.

We are comparing our recommendations with producers in a program funded by our Kentucky Soybean Board. In that program, seeding rate is often compared and, on average, the university practices are more profitable. These results are challenging producers to be more efficient with their input costs and more profitable on their returns. The results from this ongoing Hatch project, and the related research, were discussed at about 30 meetings during the calendar year.

2011 Publications

Lee, C. and J. Herbek. 2011. Soybean planting in Kentucky. AGR-130, University of Kentucky Cooperative Extension Service.