Steve Ruhl*, Extension Agriculture and Natural Resources Agent
Ed Lentz, Extension Agronomy specialist
Objective: To determine if Roundup Ready soybean seeding rates can be decreased and yields maintained.
Background |
|
| Cooperator:
Nearest Town: Major Soil Type: Tillage: Previous Crop: Soil Test: |
Tom Weiler
Chesterville Chili Conventional Corn pH - 6.8 P - 104 ppm K - 208 ppm |
| Fertilizer:
Variety: Planting Date: Harvest Date: Herbicide Program: |
None
Dekalb CX303RR May 4 October 4 Pre: Canopy 3 oz. Post: Roundup - 1 qt. |
A study using four replicates in a randomized complete block design was used to determine the effect of seeding rates of Roundup Ready soybeans on yields. DeKalb CX 303RR soybeans were used. They had a seed count of 3,200 seeds per pound. We used a John Deere 750 drill and dropped 42 pounds (134,400 seeds), 50 pounds (160,000 seeds), and 65 pounds (208,000 seeds) on a per-acre basis for our treatments. The beans were in 10-inch-row spacings. The plots were 567 feet in length and 30 feet wide. A 20-foot width cut was made in the center of the plots. Yields were determined by weigh wagon.
| Harvest Population plants/acre |
Yield bu./ac. |
| 125,000 | 48.4 |
| 145,500 | 44.8 |
| 186,500 | 45.3 |
| F = 1.93, treatment means not significantly different at P = 0.05, cv = 6.0%, lsd (0.05) = 4.8. | |
Roundup Ready soybean seed cost is in the range of $20 to $26 per 50-pound unit. Planting at rates of 65 to 95 pounds per acre will bring seed cost from $25 to $50 per acre. This is typically two to three times the seed cost for non-Roundup Ready soybeans.
From this study it looks as though seeding rates can be dropped and yields maintained. This trial will be repeated in future years.
*For additional information, contact:
Ohio State University Extension, Morrow County
871 W. Marion Rd., Suite 102
Mt. Gilead, OH 43338
419-947-1070
ruhl.1@osu.edu