Steve D. Ruhl, Agriculture and Natural Resources Extension Agent
Ed Lentz, Extension Agronomy Specialist
To evaluate the effect of seeding rate on yield of Roundup Ready Soybeans.
| Cooperator: | Tom Weiler | Fertilizer: | None |
| County: | Morrow | Herbicide: | |
| Nearest Town: | Chesterville | PRE: | Valor 1.25 oz/A |
| Drainage: | Systematically tiled | POST: | Roundup Ultra Max 26 |
| Soil type: | Sleeth silt loam | oz/A | |
| Tillage: | Conventional | Planting Date: | May 22 |
| Previous Crop: | Corn | Planting Rate: | See table |
| Variety: | Pioneer 93B72RR | Row Width: | 10-inch |
| Soil Test: | pH 7.0, P 23 ppm, | Harvest Date: | October 11 |
| K 154 ppm |
Three seeding rates were used to determine the effect of seeding rate on yields. They were 120,000, 162,500, and 227,500 seeds per acre. The seed had a germination percentage of 90%. The treatments were replicated four times in a randomized complete block design. Plot size was approximately 4/10 acre. The soybeans were planted in 30-foot wide strips, and a 20-foot wide strip was harvested and weighed using a weigh wagon. Harvest population was calculated by counting plants in 1/1000 of one acre in each plot.
Table 1. Harvest Population and Soybean Yield.a
| Harvest | ||
| Treatment | Population | Yield |
| (seeds/A) | (plants/A) | (bu/A) |
| 120,000 | 92,000 a | 54.4 a |
| 162,500 | 120,000 b | 57.2 a |
| 227,500 | 171,000 c | 56.0 a |
| LSD (0.05) | 17,329 | NS |
| F-test | 46.7 | 1.5 |
| a Means followed by the same letter in the same column are not significantly different. NS = Not Significant | ||
For 2002 the seeding rates did not have a significant effect on yields in this study. Similar results were found the previous year on the same farm with a different variety (Pioneer 93B01RR). The results support other studies indicating soybeans will compensate for thinner stands.
The moisture levels were nearly uniform across the plots. They tested in a narrow range of 11.6% to 11.8%. Thus, yields reported were not adjusted to a standard moisture level.
The authors would like to thank Todd Swetland and Pioneer Hybrid for providing the soybeans used in the study. Also thanks are extended to the cooperator, Tom Weiler.
For additional information, contact:
Steve Ruhl
Ohio State University Extension, Morrow County
871 W. Marion Rd., Suite 102
Mt. Gilead, OH 43338
419-947-1070
ruhl1@postoffice.ag.ohio-state.edu