Soybean Seeding Rate Interactions

Methods:

The soybean variety, Channel variety maturity 1.4, was either seeded in 30 in. wide rows with a planter, or in 7.5 in. wide rows with a drill, on June 8th 2017.  The seed was untreated.  Plots were seeded at either 75k, 105k, 135k, 170k, or 205k pure live seeds (PLS) ac^-1.  A total of 8 replications were completed for the 4 seeding rate beans achieved by either row or drilled beans. The 90% germination value from the seed tag was used to calculate PLS.

Results:

For this particular study there was no significant yield difference between row spacing across 8 replications. The p-value is 0.95 meaning that their was a 95% chance that the yield differences occurred due to random chance alone. Therefore yield differences between planting populations were not significant. However there is a strong yield interaction of 0.77 or 77% when both row spacing and planting population was compared separately. It’s important to note that soybean yield response to seeding rate and row spacing combinations are highly variable and that results from multiple site-years and your own on-farm testing should be taken into consideration when choosing an appropriate seeding method.

Acknowledgement:

Authors: Thandi Nleya and Graig Reicks

Trial funded by South Dakota Soybean Research and Promotion Council