Agronomic Crops Team On-Farm Research Projects 2000

Special Circular 179-01

Soybean Planting Population Rate Evaluation

Andy Kleinschmidt, Extension Agriculture and Natural Resources Agent

Objective

To evaluate the response of different soybean planting population rates in a 10-inch row width system.

Background

Cooperator: Agracola Farms County: Van Wert Nearest Town: Van Wert Soil Type: Blount silt loam Drainage: Systematic Previous Crop: Corn Tillage: None Fertilizer: None applied Row Spacing: 10 inch

Herbicide:   PRE (4/26/00): Authority (7 oz./A) + 2, 4-D Estron (8 oz./A)   POST (6/28/00): Poast Plus (20 oz./A) + Pinnacle (0.1 oz./A) Variety: Pioneer 92B61 Seeding Rates: See treatments Planting Date: May 6, 2000 Harvest Date: September 19, 2000

Methods

A study using three replicates in a randomized complete block design was established to determine the effect of seeding rate on yields in a 10-inch row width system. Seeding rate treatments were 144,000, 180,000, and 212,000 seeds per acre. Plots were 138 feet wide and a minimum of 2,342 feet long. Soybeans were planted with a White 6300 planter. The center 58 feet of each plot were harvested and weighed, and grain yield was adjusted to 13% moisture. Harvest populations were estimated by counting the number of plants in three 13-foot sections from two adjacent rows. Counts were made at three different locations in each plot.

Results

Average yields and harvest populations for each treatment are given here:

Treatment	Harvest Population	Yield
	– plants/acre –	– bu/acre –
144,000 seeds/A	117,277 A	40.4
180,000 seeds/A	141,849 B	41.8
212,000 seeds/A	162,847 C	41.7
LSD (P = 0.05) CV	5,249 1.7%	NS 4.9%
Means with the same letter are not significantly different. Yield differences were not significant at P = 0.05.

Summary

As seen in this study, planter settings can be a variable with regards to comparing target-seeding rates with final harvest populations. Germination rates can also be a factor as final stands were approximately 80% of target seeding rates. Populations were statistically different between the means of all three treatments. There were no significant differences among the three yield means.

In conclusion, data from this one-year study suggests that there were three distinct soybean populations in this study that did not produce significant reductions or increases in yield.

Acknowledgment

The author expresses appreciation to Agracola Farms for their cooperation in this study.

For additional information, contact:

Andy Kleinschmidt
Agriculture and Natural Resources Agent
Ohio State University Extension, Van Wert County
1055 South Washington Street
Van Wert, OH 45891
419-238-1214
kleinschmidt.5@osu.edu