Interseeding legumes improves pasture fertility and quality

While winter months generally aren’t reserved for planting, two University of Nebraska-Lincoln (UNL) Extension Educators share this is a time of year when interseeding legumes into pastures might be on producers’ radars. 

                  In the Feb. 12 episode of the UNL Beefwatch podcast, Beef Extension Educators Ben Beckman and Brad Schick discuss why interseeding legumes can benefit producers and which options might provide the best results. 

 Considerations for interseeding legumes

                  “Winter usually isn’t a time when we think about doing any planting or seeding, but for many legume species, the seeds are winter-hardy, and with soil contact there is a chance of germinating and growing in the spring,” explains Beckman. 

                  According to a corresponding Beefwatch newsletter written by the pair, most legume species are high in protein and energy. Providing quality forage options – alfalfa, clover or birdsfoot trefoil in this case – can positively impact animal condition and overall productivity. 

                  In addition, Schick shares, “Adding legumes to a pasture or hayfield can increase the quality of the pasture and hay, and the need for fertilizer over the lifetime of the pasture is reduced.” 

                  Legumes are well known for their ability to fix nitrogen from the atmosphere into a form usable by plants, note Beckman and Schick. This attribute has the potential to save producers in nitrogen fertilizer application costs. 

Choosing pastures for interseeding

                  Beckman shares the first step to a successful interseeded legume stand is making sure the pastures producers select are appropriate for interseeding. 

                  “Doing soil tests and knowing the pH and phosphorus levels, as well as the type of soil in the pasture are beneficial to getting legumes up and running,” Beckman says. “Legumes are sensitive to herbicides, so a weed-infested pasture a producer knows they will spray might not be a good candidate.” 

                  He continues, “Critically thinking, producers have to figure out if the input costs are worth the extra fertilization the legumes provide. We can add phosphorus or lime to work on soils with pH issues, but we have to make sure the costs balance out.” 

                  Often, Beckman notes, the decision isn’t easy. Sometimes the best thing a producer can do is accept a certain pasture isn’t right for interseeding, while on the other hand, a pasture receiving nitrogen fertilizer to increase forage production might save a producer money in the long-run if it is interseeded with nitrogen-fixing legumes. 

Preparing seeding sites                 

                  After selecting pastures for interseeding, Beckman and Schick share there are certain management strategies to ensure a strong legume crop germinates. 

                  “Pastures which were heavily grazed in the fall are great candidates for interseeding because the established forbs and grasses will be slightly stressed,” says Beckman. “Legume seedlings in those pastures will have a better chance of establishing themselves before they have to compete with surrounding plants.”

                  For producers planning to interseed with legumes, spring management practices such as targeted or flash grazing can knock down established plants without damaging seedlings, the pair notes. 

Seeding strategies

                  “Feeding seed and frost seeding are good options in the winter when there may be more labor available than in the spring during planting and calving,” says Schick. “Frost seeding is great because it doesn’t matter what the weather is as long as the field is open and there is moisture available in the spring.” 

                  Frost seeding allows the natural freezing and thawing of the ground to basically plant the seed, according to the newsletter. Although, broadcasting seeds across the pasture requires a limited amount of snow, Schick adds. 
                  “After broadcasting seed in thick snow, the seed has the possibility to wash into the neighbors’ fields or down the creek,” he says. 

                  Schick shares while the seeding rate depends upon the legume species and the goals of the producer, a general rule of thumb is two to three pounds of seed per acre. With this method, producers can shoot for 25 to 40 percent of legumes to establish a stand over a couple years of seeding. 

                  Drilling seeds, especially alfalfa seeds, provide the best option for seed-soil contact, followed by frost seeding. On the lower end of success, Beckman notes, is feeding seed. 

                  “Cheaper legume seeds hold the opportunity for feeding seed,” he shares. “Typically, fed seeds are mixed into something like a supplement or salt mineral.” 

                  He explains the appeal to feeding seed is it is the least labor-intensive option for interseeding pastures. 

                  “Non-coated seeds have seen the best success rate for making it through the animal’s digestive system as a viable seed,” Beckman continues. “However, manure patties tend to be too dense and nutrient rich for a seedling to survive longer than a few weeks, so harrowing or knocking down patties will help seeding success rates.” 

                  Averi Hales is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.