Alan Sundermeier, Agriculture and Natural Resources Extension Agent
To evaluate the effect of seeding rate on yield of soybeans.
| Cooperator: | Ed and Howard Rosebrook | Soil test: | pH 6.7, P 24 ppm, |
| County: | Henry | K 153 ppm | |
| Nearest Town: | Deshler | Fertilizer: | None |
| Drainage: | Tile, subsurface | Planting Date: | May 30, 2002 |
| Soil type: | Hoytville clay | Planting Rate: | 225,000 seed/A |
| Tillage: | No-till | Row Width: | 7-inch |
| Previous Crop: | Corn | Herbicides: | Synchrony STS .3 oz/A, |
| Variety: | Rupp RS2333STS | Reflex 1.5 pt/A, Classic | |
| 0.5 oz/A | |||
| Harvest Date: | September 24, 2002 |
Three population rates were used to determine the effect of seeding rate on soybean yields. They were 110,000, 165,000, 220,000 seeds per acre. A Great Plains 15-foot no-till drill was used. The seed used had a germination percentage of 90%. The entries were replicated four times in a randomized complete block design. Individual planted plot size was 30 feet wide by approximately 930 feet in length. A 20-foot wide strip was harvested the length of the plot and weighed using a yield monitor on the combine.
An emerged population count was taken on June 26 at the V2 stage of the soybean by using the hoop method. Harvest population was determined by counting the soybean plants in 3 feet of row for four rows per treatment.
Table 1. Soybean Population and Yield.a
| Population | |||
| Seeding | growth stage | Harvest | |
| rate | V2 | Population | Yield |
| (plants/A) | (plants/A) | (plants/A) | (bu/A) |
| 110,000 | 134,522 a | 106,175 a | 59.3 a |
| 165,000 | 179,365 ab | 147,010 b | 61.8 b |
| 220,000 | 253,035 b | 242,300 bc | 62.6 b |
| LSD (0.05) | 97,823 | 39,096 | 1.3 |
| F-test | 4.6 | 2.3 | 1.4 |
| a Means followed by the same letter in same column are not significantly different | |||
Weed control was very good across the seeding rates. Grain moisture at harvest was 12.3%. A timely rain allowed crop yields to be near normal for this area.
This study shows that there can be a significant difference between seeding rates as it pertains to soybean yield. The optimum soybean population count in this study was 147,010 plants/A.
When planting minimum seeding rates, be sure the planting equipment is calibrated and the germination rate of the seed is known.
Thanks to Rupp Seed Co. for cooperating in this study.
For additional information, contact:
Alan Sundermeier
Ohio State University Extension, Wood County
440 East Poe Road
Bowling Green, Ohio 43402
Sundermeier5@ag.osu.edu