New Penn State Guide Tackles Weed Control in Organic No-Till Soybean Systems

Imagine a weed management system with no access to herbicides and no conventional tillage implements. Intimidated? Welcome to the world of organic no-till crop production! 

Unsurprisingly, the use of multiple, innovative weed-control tactics is an absolute necessity for farmers who go this route. That’s why integrated weed management is a major focus of Penn State’s latest publication, “Organic No-Till Soybean Production in Pennsylvania: Is It For You?” 

Even if a farmer’s ultimate answer to that question is no, this guide is still well worth perusing. With two decades’ worth of research from Penn State, Cornell, the University of Delaware, USDA and countless participating farms, the guide is a comprehensive overview of different non-chemical and non-tillage weed control options for Mid-Atlantic farmers

Cereal rye cover crop mulch is a crucial weed suppression tool for organic, no-till soybean production. (Photo credit: Claudio Rubione, GROW)

Cover Crops: The guide zeroes in on cereal rye as the best option for the region’s farmers, given its robust biomass production, but it also covers alternate cover crop options. Ultimately, the authors run through a detailed list of considerations, including:

  • Growing season windows
  • Termination timing
  • Fertilization needs
  • Seeding rates
  • Variety selection
  • Seeding methods

The section on cover crops also digs into the ins and outs of roller-crimping techniques, as well as the biology of how cereal rye mulch can suppress weeds. 

The guide covers the challenges of cover crops, as well. That includes how to manage and minimize volunteer cover crops that survive roll-crimping, as well as an overview of weeds that aren’t easily managed by cover crops. It also touches on the effect of organic no-till cropping systems on insect populations and soil health.

Common ragweed, one week post weed-electrocution. (Photo credit: Annika Rowland)

Growing Better Soybeans. The guide covers a basic but essential tactic of growing soybeans that are better equipped to outcompete weeds. The authors explain how to maximize weed control with soybean variety selection, seeding rate, seeding methods and row spacing.

In-Season Weed Management Options. With herbicides and tillage out of the discussion, the guide examines some less common in-season control options, namely:

  • High-residue cultivators: This type of equipment aims to minimize soil disturbance, but does dig in enough to sever weed roots. Some considerations are frequency of passes, wet soil conditions, residue effects and costs. 
  • Inter-row mowing: This section examines the use of inter-row mowers, which chop weeds down to a couple inches above the soil surface, primarily in 30-inch soybean row systems. 
  • Electric weed control: The guide gives a glimpse into the burgeoning industry of weed electrocution devices, such as the Weed Zapper. 

You can find the guide in its entirety here. It also lives in the GROW Resources page, under cover crop bulletins. 

Text by Emily Unglesbee, GROW