Ohio State University Extension Bulletin

Agronomic Crops Team On-Farm Research Projects 1999

Special Circular 176-00


7.5-Inch vs. 15-Inch Row-Width Evaluation for Soybeans

Andy Kleinschmidt*, Extension Agriculture and Natural Resources Agent
Gary Prill, Extension Associate, Farm Focus/Research Coordinator
Ed Lentz, Extension Agronomy Specialist

Objective: Evaluate yields of two different soybean varieties as affected by two different row widths.

Background


Cooperator:
County:
Nearest Town:
Soil Type:
Drainage:
Previous Crop:
Tillage:
Fertilizer:
Soil Test:
Marsh Foundation/Farm Focus
Van Wert
Van Wert
Hoytville silty clay loam
Tile
Corn
Fall deep-tilled and spring cultivate (2x)
None applied
pH, 6.2
P, 57 ppm
K, 188 ppm
Herbicide:
Varieties:
POST - 1.5 pt/acre Roundup Ultra
Wellman 3836 RR (treated)
Wellman 3731 RR (treated)
Planting Rate:
Planting Date:
Harvest Date:
See methods
May 17, 1999
September 28, 1999

Methods

Each soybean variety was grown in separate test blocks with each variety block containing three replicates of the two spacing treatments. For the 7.5-inch row-spacing treatment, planting population was 195,000 seeds/acre. For the 15-inch row-spacing treatment, planting population was 180,000 seeds/acre. Soybeans were drilled with a John Deere 750 no-till drill for the 7.5-inch row-spacing treatment and planted with a John Deere 7000 Max Emerge planter with splitter attachment for the 15-inch row-spacing treatment. Harvest plot size was 28 feet wide x 1,075 feet long. Each plot was harvested and weighed by a weigh wagon to determine grain yield at 13% moisture. Harvest populations were estimated by counting the number of plants in three-foot sections from two adjacent rows. Counts were made at three different locations in each plot.

Results

Variety Treatment Harvest
Population
---plants/A---
Yield
---bu/A---

Wellman 3731 RR 7.5 inch drilled
15 inch planted
205,216
154,880
38.3
39.0
Wellman 3836 RR 7.5 inch drilled
15 inch planted
236,192
138,747
37.3
34.2

Wellman 3731 RR: Yield difference not significant at P = 0.05, CV = 2.2%.
Wellman 3836 RR: Yield difference not significant at P = 0.05, CV = 3.8%.

Summary and Notes

In this study, row-width evaluation on soybeans showed no significant difference between yields at 7.5-inch row-spacing treatment and 15-inch row-spacing treatment. There were inconsistent results between harvest population and target seeding population rates using the drill. Harvest population with the splitter was more consistent with the target seeding rate. Yields were not reduced statistically, however, between the two row-spacing treatments. In conclusion, this one-year study suggests that there is no significant effect on yields between the 7.5-inch row-spacing treatment and the 15-inch row-spacing treatment. Results may be different in another year with normal rainfall, since yields were reduced at this site due to dry weather.

Acknowledgement

The authors express their appreciation to Wellman Seeds, Inc., and Monsanto for donating material used in this study.

*For additional information, contact:

Ohio State University Extension, Van Wert County
1055 South Washington Street
Van Wert, OH 45891
419-238-1214
aklein@postoffice.ag.ohio-state.edu


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