This is a 2-3 page research summary that will be used for publication on the MPGA website. Contents will
also be used for extension to our grower members. This report template will be used for 2 purposes:
1. As an annual extension report, to be submitted annually. It is understood that these are
preliminary results and final results will be reported in the final report.
2. As a final extension report, to be submitted by the completion date, in addition to a detailed
technical/scientific report (no template).This will be used to provide growers with a clear, succinct
message on how check-off dollars are being utilized to improve their operation and industry.
EXTENSION REPORT
Project Title: Effect of Soil Temperature at Different Planting Dates,
and Residue Management, on Soybean
Date: March 25, 2015
Project Start Date: April 2014 Project End Date: March 2018
Principal Researcher: Ramona Mohr
Position: Research Scientist
Address: Agriculture and Agri-Food Canada, Brandon, MB
Email: Ramona.Mohr@agr.gc.ca
Phone: 204-578-6556
OBJECTIVES
The objectives of this research project are:
1)
To determine the effect of soil temperature at different planting dates on soybean growth, yield
and quality
2)
To determine the effect of residue management on soybean growth, yield and quality
SUMMARY
Methods:
Two small-plot studies were initiated at each of Brandon, Carberry, Portage and Roblin, MB in 2014.
Study 1: Effect of soil temperature at different planting dates on soybean
A factorial combination of two seeding dates (early, late) and three soil temperature treatments (cold,
control, warm) was arranged in a split-plot design with four replications, with seeding date as main plot
and soil temperature as subplot treatments. In order to produce three soil temperature treatments,
plot areas were covered in early spring with one of three different materials: 1) Styrofoam and/or
reflective material to insulate the soil and produce a “cold” temperature treatment; 2) black plastic to
warm the soil to produce a “warm” temperature treatment; and 3) white+clear plastic to reflect the sun
to produce a “control” treatment. Coverings were removed shortly before the designated planting
date, and a Roundup-Ready soybean cultivar was planted. Generally-accepted agronomic practices
were employed with respect to nutrient and pest management, and harvest.
Data collected included emergence date, plant density, crop growth stage periodically through
the growing season, early-season biomass, seed yield, seed quality, and soil temperature and
moisture content.
Study 2: Effect of residue management on a subsequent soybean crop
A randomized complete block design consisting of four replicates of six residue management
treatments (tilled black; standing wheat stubble +/- straw; standing oat stubble +/- straw; standing
canola stubble with straw) was established in 2014. Residue treatments were established in 2014,
and soybean will be established in these plots in 2015 using generally-accepted agronomic practices.
Manitoba Pulse Growers Association Inc.
October 2, 2013
Preliminary findings:
Study 1. Effect of soil temperature at different planting dates on soybean
In 2014, seeding was delayed at all experimental sites due to wet spring conditions. Early
seeding dates ranged among sites from May 26-29th, with late seeding treatments imposed 9-15 days
thereafter.
Analysis of detailed soil temperature data measured during the growing season is currently
underway. Preliminary soil temperature data from the Brandon and Carberry sites suggests that the
various soil coverings produced the greatest and most long-lasting effect on soil temperature for the
first planting date at Brandon. At both Brandon and Carberry, the average soil temperature during the
second planting was similar to the first planting. Soil coverings had been kept in place until shortly
before planting for both seeding dates at both locations. These preliminary findings confirm that the
various soil coverings can be effective in producing differences in soil temperature that may last for
several days, thereby allowing an assessment of the effect of different soil temperatures on soybean
seeded on a given date. These initial results are being used to refine the experimental protocol used
in future years of this study, so as to improve our ability to understand the relationship between soil
temperature and soybean growth under field conditions.
At all sites, higher yields were achieved when soybean was planted between May 26-29th than
between June 4-11th. Yield in the June-seeded treatments averaged 65, 68 and 80% of May-seeded
treatments at Carberry, Brandon and Portage, respectively (Table 1). At Roblin, frost damage to the
June-seeded plots resulted in very low yields. Soil temperature treatment did not have a statistically
significant effect on yield at any sites in 2014, although yield tended (P=0.06) to be higher in the warm
treatment at Carberry (Table 1). Earlier seeding decreased test weight at Brandon and Carberry, and
increased seed weight at Carberry. Soil temperature treatments did not vary with respect to test
weight or seed weight in 2014.
The data presented herein is preliminary, from the first year of a three-year study to be
continued in 2015 and 2016. As additional data is collected over the course of the study, further
analysis will be conducted to relate treatment, and soil temperature within the various treatments, to
crop establishment, growth and yield.
Study 2: Effect of residue management on a subsequent soybean crop
Residue management treatments were established in 2014, and soybean will be seeded in these plots
in 2015. Experiments will continue in subsequent years, with residue management treatments
established in 2015 and 2016, and soybean planted into these residue management treatments in
2016 and 2017.
2
Manitoba Pulse Growers Association Inc.
October 2, 2013
BENEFITS/IMPACTS TO PULSE GROWERS
The introduction of early-maturing soybeans has significantly increased soybean production in many
regions of Manitoba. However, frost and near-freezing temperatures in spring and fall remain a risk
for soybean production, particularly in “non-traditional” production areas.
Potential may exist to reduce the risk associated with frost and/or near-freezing conditions
through management. Selection of well-adapted cultivars suited to short-season areas is critical.
However, planting date, and management of preceding crop residue, may also influence early-season
temperatures and crop growth. A better understanding of the impact of these management practices
on soybean growth, yield and quality under Manitoba conditions may help growers to refine
management practices in order to reduce production risk and optimize soybean production in this
province.
COMMUNICATION
Extension events: Information regarding this research was presented at a field day hosted by the
Manitoba Pulse Growers Association and the Brandon Research Centre at the AAFC Field
Research site near Brandon, MB on July 31, 2014; and at a field day hosted by Manitoba
Agriculture, Food and Rural Development (MAFRD) at Isabella, MB on August 14, 2014.
Information regarding this research will be presented at the Soybean Grower Information Day,
March 27, 2015, Morris, MB.
Acknowledgements: Our thanks to the staff and students at Agriculture and Agri-Food Canada
(Brandon), the Canada-Manitoba Crop Diversification Centre sites (Carberry, Portage), and the
Parkland Crop Diversification Foundation (Roblin) for their contributions to the conduct of the 2014
field studies.
Please submit to Roxanne Lewko, Research Program Coordinator: roxanne@manitobapulse.ca
3