Key Takeaways

• Emerging rotation option: Yellow winter pea is an emerging cool-season legume crop showing potential for dryland cropping systems in western Nebraska.

• Promising varieties: Multi-year UNL research has identified several yellow winter peas varieties with promising performance under western Nebraska conditions.

• Planting window: Research indicates Sept. 7–Oct. 1 is the most reliable planting window for maintaining yield potential.

• Seeding rate: The economically optimal seeding rate ranges from 300,000–340,000 seeds per acre. 

• Planting depth: Research indicates 2-inch seeding depth may perform better than depths of 1 or 3 inches.

Yellow winter pea is gaining attention as an adaptable cool-season legume in the semi-arid Central Great Plains, particularly in western Nebraska. Its ability to fit into fall-planted systems yellow winter pea it a potential option for diversifying dryland crop rotations. Research on yellow winter peas at the University of Nebraska–Lincoln (UNL) began with variety testing in 2022. These early trials focused on evaluating cold tolerance, winter survival and yield potential among available varieties. 

This article highlights the agronomic performance of two varieties from those early trials that are currently commercially available. Additional varieties showing promising performance in western Nebraska are also available on the market, while other entries in UNL variety trials are breeding lines that may become commercially available in the near future.

The Cropping System Lab at West Central Research, Extension and Education Center (WCREEC) in North Platte expanded the research beyond variety testing to evaluate agronomic management practices, with support from the Nebraska Dry Pea and Lentil Commission. 

Planting time is one of the most important management decisions for yellow winter pea. Multi-year research identified Sept. 7–Oct. 1 as the optimal planting window, with planting during this period maintaining 95–100% of maximum yield. Planting earlier or later increased the risk of yield loss, likely because of poor fall establishment, greater winter injury or limited spring recovery.

Seeding rate is another key factor affecting yield and profitability. Yield increases with seeding rate, but only to a point, as greater plant-to-plant competition at higher rates limits yield response. Multi-year trials were used to identify both the agronomically optimal seeding rate, which maximizes yield, and the economically optimal seeding rate, which accounts for seed costs and grain prices.

The agronomically optimal seeding rate (AOSR) was 388,000 seeds per acre, representing the rate that maximized yield without considering seed costs or grain prices (dotted orange line). The economically optimal seeding rate (EOSR) was lower and varied with grain price (shaded area). At $6 per bushel, the EOSR was approximately 295,000 seeds per acre, increasing to approximately 344,000 seeds per acre at $12 per bushel and maximizing return on investment. 

Planting depth is another agronomic factor under evaluation. In the first year of trials, yellow winter pea planted at 1 or 3 inches yielded less than pea planted at 2 inches. The 2-inch depth provided the best balance between early vigor and winter survival (Figure 4). Although additional research is underway to determine the optimal planting depth, first-year results showed a clear advantage at the 2-inch depth.

Achieving the right agronomic balance is important for the successful adoption of yellow winter pea in Nebraska. Based on UNL research to date, growers in western Nebraska interested in the crop should consider the following management guidelines:

• Plant between Sept. 7 and Oct. 1.
• Target 300,000-340,000 seeds per acre.
• Seed winter peas 2 inches deep. 
• Use winter-hardy varieties with consistent performance across western Nebraska environments (see the UNL winter pea variety trial results).

For questions about incorporating yellow winter pea into crop rotations, please contact Nicolás Cafaro La Menza or Dipak Santra, or the Nebraska Dry Pea and Lentil Commission.