Growing Soybeans – Did You Know?

1. Yield is determined by the following:  plants/ac, nodes/plant, pods/node and seeds/pod.
2. Yield is optimized when crop emergence is close to the same time for all plants.  This trumps earlier seeding or more growing space.
3. Higher speed of seeding will influence depth control and this may introduce variability in plant emergence.
4. Seeding depth of ¾ inch to 1 inch is ideal, 1.5 inches should be the maximum.  This will result in more consistent emergence and healthier seedlings.
5. Nodulation begins at the 3^rd to 4^th trifoliate.  The crop needs about 20 lb/ac N to get established.  If the top 6 inches is very low, this may need to be addressed with extra N fertility.
6. A strong inoculant program is very important coming off a dry year i.e. rhizobia in the soil may not have survived well.
7. Critical weed-free period is V1 to R1 for soybeans in Manitoba.  This is influenced by row spacing, final plant stand and variety.
8. Lamb’s quarters, wild buckwheat, volunteer canola and kochia are weeds that glyphosate can be weak on.  Control of these weeds may require a strong pre-seed program or add-in product to optimize weed control.  This will also help with glyphosate-resistant weed management.
9. Peak moisture draw by the crop is at the R1 to R6 stage at 0.2-0.3 inches/day.
10. Dry weather can reduce rhizobia performance which can decrease nitrogen fixation and potentially lower the protein level in seed.
11. Dry weather and high temperature during maturation can trigger green colour in seed because of reduced production of chlorophyll-breakdown enzymes by the plant.

Talk to your local Shur-Gro agronomist about additional production advice for your soybean crop.