Spring checklist for improving soybean yields
The following checklist summarizes management practices that are proven to contribute to high-yielding soybeans.
Inspect, repair and calibrate planting equipment. Uniform seed
spacing in the row will improve yields. Small seed will plant more
evenly and will experience less mechanical damage than large seed when
planted with a drill equipped with a fluted metering system. Always
calibrate your drill by seeds per foot of row or seeds per acre.
Recalibrate whenever seed size changes.
Control weeds prior to planting. Always plant into weed-free
fields. Delayed burn-down applications have resulted in yield losses of 8
bushels per acre in MSU research trials. Tillage and/or herbicides can
be used to control weeds.
Broadcast potash on coarse-textured or organic soils if needed. Fall
applications of potash are not recommended on coarse-textured soils
having CECs less than 6 meq/100 g or on organic soils due to the
potential for leaching losses.
Apply phosphate fertilizers if recommended. MSU recommends
applying maintenance level phosphorus (0.8 lbs. of actual P2O5 per
bushel) when phosphorus soil test levels are between 15 and 30 ppm. No
phosphorus is recommended when soil test levels exceed 40 ppm.
Plant into good soil conditions. Adequate and uniform soil
moisture, soil temperatures higher than 50oF and a level surface will
promote uniform seedling germination and emergence.
Plant soybeans early. The first two weeks of May is considered
the ideal planting window for soybeans in the lower half of the Lower
Peninsula. Yield losses of 0.6 of a bushel per acre per day can occur
when planting is delayed past May 15. Please see the Soybean Facts fact
sheet entitled “Early-Planted Soybeans - Risks, Benefits and Recommendations ”when planting prior to May 1. You can find this bulletin at http://web1.msue.msu.edu/soybean2010/.
Inoculate seed whenever soybeans are planted. Researchers from
Michigan State University and Ohio State University report average yield
increases of 1.3 bushels per acre from using inoculants on fields
having a history of soybean production.
Consider a soil-applied residual herbicide application followed by a post-emergence application. Benefits
include: reduced early-season weed competition, consistent control of
weeds that emerge over a long time period, consistent control of
hard-to-control weeds and herbicide resistance prevention.
Plant at the optimum seeding rates. Plant 175,000 seeds in 7.5” rows, 150,000 seeds per acre in 15” rows and 130,000 seeds per acre in 30” rows.
Plant in narrow rows. University research trials have shown that planting in narrow rows significantly increases soybean yields.
Plant at the optimum depth. Plant beans between ¾-inch and
1-1/4-inch deep. In general, plant at the shallower end of the range
when planting early and in no-till, and plant at the deeper end of the
range later in the season.
Plant a range of maturity groups. Planting a range of soybean
maturity groups spreads your risk during the growing season, allows more
of the crop to be harvested at the optimum stage and allows for timely
wheat planting.
Use seed treatments where warranted and provide uniform coverage of the seed. Fungicide
seed treatments are warranted when planting very early and/or where
pythium is known to be a problem (Southwest Michigan). Insecticide seed
treatments are warranted when seedcorn maggot, wireworm or bean leaf
beetle damage is expected.
Monitor fields closely beginning at emergence. Diagnose
emergence problems early. Emergence can take six to 18 days depending on
soil temperature and soil moisture conditions. If slow and uneven
emergence occurs, dig up the delayed plants and look for disease or
insect damage. Plant stands of 100,000 plants per acre will produce
optimum yields if the plants are relatively evenly spaced. After
emergence, continue checking fields for bean leaf beetles and black
cutworms. Monitor weed heights and use this information to time
post-emergence herbicide applications.