2013
Best management practices to break the soybean yield barrier
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Contributor/Checkoff:
Iowa Soybean Association
Category:
Sustainable Production
Keywords:
Field management Nutrient managementSoil healthTillageYield trials
Parent Project:
Best management practices to break the soybean yield barrier
Lead Principal Investigator:
John Lawrence, Iowa State University
Co-Principal Investigators:
Project Code:
Contributing Organization (Checkoff):
Iowa Soybean Association
(n/a)
Institution Funded:
Iowa State University
(n/a)
Brief Project Summary:

This project involves a verification program that works directly with farmers interested in high yields. The specific objective of the project is to verify the impact of using current management recommendations from ISU compared to current practice on farms that have been identified as low yielding. The project involves Iowa State University Extension field agronomists working with 2-3 soybean farmers and the appropriate Corn and Soybean Initiative agribusiness partners to systematically apply best management practices to improve soybean yields and profitability. The project results will be developed into educational materials for soybean field guides, presentations, media articles and...

Unique Keywords:
#crop management systems
Information And Results
Final Project Results

The greatest difference in average yields between SCN-resistant and widely grown susceptible varieties in any variety trial location in 2013 was 18.4 bushels per acre (or 56 percent), which occurred at the experiment conducted in a very sandy field near Fruitland.

Overall, soybean yields were the lowest in the variety trial conducted near Newell in the northwest part of the state. Parts of the experiment were flooded early in the season at that location. Nonetheless, yields of SCN-resistant varieties averaged a little more than 37 bushels per acre, which was 40 percent greater than yields of the average yield of 26.7 bushels per acre for the widely grown susceptible varieties at that experiment.

Initial SCN egg population densities at planting for the nine variety trial locations in 2013 ranged from 431 to 10,952 eggs per 100 cubic centimeters (cc) of soil, which is a little less than a half-cup of soil. This was an unusually wide range of initial SCN population densities among the variety trial locations. The final or end-of-season SCN egg population densities under the SCN-resistant varieties were one-fifteenth to one-half of the densities that developed under the widely grown susceptible varieties (figure 2). The amount of soybean yield loss caused by SCN is directly related to the SCN egg population density, so the nematode control provided by SCN-resistant varieties will pay dividends in the form of higher yields the next time soybeans are grown.

The greatest level of nematode control provided by SCN-resistant varieties was at the variety trial near Urbana in 2013 (figure 2). The average SCN population density in the field before the experiment was planted was 431 eggs per 100 cc of soil. At harvest, SCN population densities in this experiment increased to 1,120 eggs per 100 cc of soil under the SCN-resistant varieties. In contrast, the end-of-season SCN population density under the widely grown susceptible varieties in that experiment was 16,350 eggs per 100 cc of soil.

The greatest amount of SCN reproduction on SCN-resistant varieties, as a whole, occurred in the experiment near Leighton in 2013. The field had an initial SCN egg population density of 1,694 eggs per 100 cc of soil; final population densities were 11,745 eggs per 100 cc of soil on average under the SCN-resistant varieties and 28,267 eggs per 100 cc of soil under the widely grown susceptible varieties.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.