Submitted by: John Heard, Manitoba Agriculture, Soil Fertility Specialist
Spring 2019 (like 2018) has brought many questions about seedplaced fertilizer rates for canola. Several factors are causing concern:
- Drier soils – which increase the risk of seed toxicity
- Desire to apply sufficient P to meet crop removal – since many fields have seen decreasing P levels due to high yield. P removal is about 1 lb P2O5/bu, so high yield potential fields are looking at high P replacement rates.
- Increased use in low disturbance, low seedbed utilization (SBU) drills. Many new openers are arriving on the scene, which are “close-to-seed” sidebanding for which one may need to consider as seedplaced.
Desire by growers to reduce seeding rates for cost savings. Most research studies investigating seedplaced fertilizer injury were seeded at some 150 seed/m2, about double what some farmers are now targeting.