2005 Annual Report: Planting Populations in Soybeans
With the increasing cost of seed and the ever fluctuating market, producers are trying to reduce their inputs as much as possible to maximize their net profit. One such input that can be varied is the seed population at planting. This demonstration is designed to help producers make decisions on planting rates taking into account conditions in Northwest Missouri.
Methods and Materials
This demonstration consisted of plots 250-feet long and 12, 30-inch rows wide. The seed was no-till planted on May 17, 2005 into corn stubble and harvested on October 11, 2005. The six different planting populations used were:
- Plot #1 - 243,000 seeds/acre
- Plot #2 - 218,000 seeds/acre
- Plot #3 - 189,000 seeds/acre
- Plot #4 - 178,000 seeds/acre
- Plot #5 - 151,000 seeds/acre
- Plot #6 - 130,500 seeds/acre
All of the soybeans emerged at approximately the same time regardless of the planted population. Emergence varied from 94.0% to 96.6% as summarized in Table 1.
Table 1 - 2005 Soybean population demonstration emergence rates.
Yields ranged from 60.7 to 64.6 bu/acre. The yield data is shown in Table 2. With an average of 62.4 bu/acre and a standard deviation of 1.5 bu/acre, there was no significant difference between the different planted populations.
Table 2 - 2005 Soybean population demonstration yield data.
Figure 1 shows the average yields for each planting population over the past four growing seasons. Previous research had suggested that planting approximately 180,000 - 200,000 seeds/acre would provide the best net return for seed planted. This demonstration supported the past research.