While the results of this analysis show no consistent yield advantage for planting early, there was also no consistent yield loss (except for ultra-early plantings in the Deep South) associated with early plantings.
"If the soil is ready for planting in April, producers should feel free to plant, but they shouldn't expect higher yield," advises Egli.
Planting into cold, wet soils, however, can reduce seedling emergence and stand, which may require replanting to avoid yield loss. Unacceptable stands may be more common if seeding rates are reduced to the minimum to reduce seed costs.
Average yield declined rapidly when planting was delayed after 30 May in the Midwest, 7 June in the Upper South, and 27 May in the Deep South at rates ranging from 0.7 (Midwest) to 1.1 (Upper South) and 1.2 ( Deep South) percentage points per day. At these rates, delays of just 2 weeks will reduce yields by approximately 10 to 20%.
There may be no particular advantage for early planting, but there was a clear disadvantage for planting late, after the critical date in late May or early June. Soybean producers can maximize their yield and profits by making sure planting is completed before the critical date.
|Contact: Sara Uttech|
American Society of Agronomy