by Amanda Smith, Associate Editor

In a matter of weeks, equipment will hit fields across the Midwest and Northeast. While hybrid decisions are already locked in for the planting season, there's still time to evaluate planting densities, whether you're using a conventional or brown midrib (BMR) variety.

Usually fields that are planted at too high of a population have greater lodging, poorly filled ear tips and a greater number of barren plants, said Joe Lauer, with the University of Wisconsin-Madison. The ideal plant population depends on:

• Soil type: Heavier, finer textured soils have better water holding capacity and can support high populations.
  
• Planting date: As population rises, an early planting date becomes more important.
  
• Hybrid: Shorter, earlier hybrids are usually more responsive to high populations.
  
• Fertility: High populations remove more soil nutrients that must be replaced.
  
• Moisture: Plenty of moisture is needed for higher populations to be advantageous.

The main issues encountered by crops in overplanted fields are associated with drought conditions and the hybrid's ability to withstand stress, noted Lauer, in the Midwest Forage Association's Forage Focus.

Typical harvested plant population recommendations for corn grown for grain in Wisconsin range between 30,000 and 34,000 plants per acre. If fields have lighter soils, 28,000 plants per acre is about right, notes Lauer.

If the field will be harvested for corn silage, then raising plant density 2,000 to 3,000 plants per acre over grain recommendations is a reasonable decision. This will improve forage yield and milk per ton, with a slight quality trade-off. Before adjusting densities, work with your local agronomist to ensure your hybrid can withstand a population change.

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(c) Hoard's Dairyman Intel 2015
March 30, 2015