Is it Time to Revisit Seeding Populations?

A few weeks ago, we noted that higher corn plant populations have been the biggest source of trendline yield gains. This makes intuitive sense but doesn’t align with recent plant population trends, which reveal a plateau.

Since the 1980s, Iowa corn plant populations have increased by nearly 300 plants per acre annually. But in recent years, the measure has been mostly sideways. When considering the pace of ten-year segments, Iowa plant populations increased by more than 400 plants annually between 1988 and 1987. The +400 pace was repeated between 2002 and 2011. The most recent ten-year pace, however, is much lower. Even approaching zero.

The slowdown isn’t unique to Iowa. Across Illinois, Indiana, and Minnesota, the general trend was big population gains in the 1990s and 2000s, followed by a slowdown since 2010. The most recent pace is at, or near, the slowest observed since 1980.

Wrapping it up

It’s unclear why corn plant populations have flattened in recent years. It’s also unclear what the implication will be for the national corn yield trend in the coming year. However, this is a good reminder for producers to review their farm-level seeding rates. Have seeding rates kept up with prevailing agronomic and economic factors?