Establishing a Cool Season Legume Grass Finishing Pasture

In 2022, planting objectives were met in the Pleasant Valley and Kila locations, but not the Stanford location.  The Stanford location was so dry that the Stanford rancher, Jess Alger, decided not to plant because he believed, based on experience, that germination would be low, and of those seeds that did germinate, seedling survival would also be low.  There is no irrigation at the Stanford location.  Moisture levels at the Pleasant Valley and Kila locations were deemed acceptable, primarily due to spring rains.  In Pleasant Valley, sampling at 5 randomly selected locations was done on 8/17/22, on approximately 10 acres that was seeded to Shoshone sainfoin and Potomac orchardgrass.  The average number of sainfoin plants per square foot was 2.088.  There was a small amount of irrigation available at this location.  At the Kila location, sampling at 5 randomly selected locations on approximately 7 acres seeded to Shoshone sainfoin and Potomac orchardgrass was done on 8/16/22.  The average number of sainfoin plants per square foot was 1.53.  Also at the Kila location, sampling at 5 randomly selected locations on approximately 3 acres seeded to birdsfoot trefoil and Potomac orchardgrass was done on 8/17/22.  The average number of birdsfoot trefoil plants per square foot was 1.854.  These two acreages are adjacent.  No irrigation was available at Kila. 

We want to see what the second year of these plantings looks like before we make any recommendations.  Right now, we would view the results as successful, but it's possible that these plantings will not overwinter well.  And even if they do overwinter well, the forage production may not be substantial enough to be viewed as successful.  We will be able to assess both of these points by the end of this summer.  And finally, we intend to graze these pastures sometime in summer, so we will also have some visual, qualitative, results regarding grazing.

On 9/4/23 at Pleasant Valley, there were 10 sampling locations with an average of 0.117 sainfoin plants per square foot, which is a huge drop from the 2.088 approximately a year earlier.  On 9/28/23 at the Kila location, there were 5 sampling locations in the sainfoin planting with an average of 2.45 plants per square foot, which is an increase of 0.92 plants per square foot from 2022.  On the same date at the Kila location, there were 5 sampling locations in the birdsfoot trefoil planting with an average of 3.02 plants per square foot, which is an increase of 1.116 plants per square foot from 2022.  At the Stanford location on 10/3/23, the Stanford rancher, Jess Alger, and the PI, Ronald Wade, were unable to find any sainfoin plants.  Jess Alger reported that the spring/2023 seeding did germinate and had an adequate number of small sainfoin plants a few weeks later.  Grass plants at all three locations were adequate; it is only the absence of legumes at Pleasant Valley and Stanford along with an adequate presence of legumes at Kila that is noteworthy. 

Although it was not a part of the grant proposal, the PI collected soil samples and had a Haney soil test performed by RegenAgLab.  From the analysis reports and also a discussion with a staff member, we do not see any soil differences that would account for the legume die-off at two locations and the continuing presence of legumes at the third location.   However, Ryan Wade at Pleasant Valley and Jess Alger at Stanford both reported major grasshopper infestations at these locations, while Ronald Wade at Kila reported a few grasshoppers, but nothing that could be called an infestation.  At this point, we believe that grasshopper infestations probably account for the legume die-off at Pleasant Valley and Stanford.

Assuming adequate moisture, Ryan Wade at Pleasant Valley and Jess Alger at Stanford will replant sainfoin in spring/2024.  The PI, Ronald Wade, will sample both these locations in June/2023, which is prior to the normal later time of an infestation, when these do occur.

MODIFICATIONS:  As noted above, replanting was done in spring/2024 at Pleasant Valley with a no-till drill.  That is, the previously seeded pasture was not plowed again since the grass seeding was deemed successful.  When sampled in early fall/2024, almost no sainfoin plants were found.  The conclusion is that it is unlikely to be able to establish sainfoin at this location in a no-till situation without prior plowing of the soil.                                   

At the Stanford location, grasshoppers were very abundant in spring/2024, so replanting was not done at this time.  Instead, sainfoin planting was done in fall/2024, but no sampling has occurred as of this time.  Therefore, no conclusion can be drawn as to success or failure at this location.

At the Kila location, sampling that showed good numbers of both sainfoin and birdsfoot trefoil in 2023 leads to the conclusion that both legumes,  planted in spring of 2022, overwintered successfully from the winter of 2022-2023.  Therefore, the conclusion is that both legumes can be established successfully, provided there is prior plowing of the soil, and can overwinter successfully.  Based on the results at Marion and Stanford, it must also be concluded that young sainfoin plants in their first year are very susceptible to grasshopper infestations.  As noted above, sample numbers of both sainfoin and birdsfoot trefoil at the Kila location dropped to a very low number by the fall of 2024.  However, cattle numbers grazing this location were much higher in 2024 than in either 2022 or 2023, which leads to the conclusion that cattle numbers must be managed so as to not adversely impact the legumes.  An observation of interest is that the Canada thistle in association with these legumes was also adversely impacted, presumably by cattle eating the young thistle plants while they grazed the nearby desirable legumes.  The total of 10 acres, 7 of sainfoin and 3 of birdsfoot, is part of a much larger pasture of only grass.  During the three years of this study, 2022-2024, the entire pasture was not set up for rotational grazing.  It is now set up for rotational grazing for 2025, and it will be grazed in this manner going forward.  Graphs that show legume numbers and cattle numbers during 2022-2024 are shown in the Education and Outreach section below.    

Part of the process of determining what works in establishing a legume pasture for grazing is also finding out what doesn't work.  The 'failures' noted above are examples of the latter.