On farm replicated trials

Wick, Franzen, Kandel, Ransom, Wells; farmers Breker, Bell, Toussaint, Hohenhause, Thilmony in ND; Rollofson, Martinson in MN

North Dakota farms

Interseeding cover crops: The project’s twin row high-clearance planter interseeded cover crops at five farmer’s fields. Total acres interseeded with the interplanter was approximately 600 acres. Farmers who used our interseeder were Joe Breker (corn-cover crops) and Jeff Breker (corn-sorghum), Rutland, ND; Joe Bell (soybean-covercrops), Gardner, ND, Doug Toussaint (sunflower-cover crops), Wahpeton, ND, at the Soil Health and Agriculture Research Extension (SHARE) farm Mooreton, ND and M. and A. Hohenhause, Lisbon, ND. Cover crops interseeded were radish, rye, winter camelina mix into corn at V6, forage sorghum into corn, cut for silage at the end of the season, cover crops mix in sunflower. Grain yield did not decrease at any of the interseeded locations.

2. Joe Breker and Doug Toussaint planted 50 acres each of winter camelina in the fall of 2017. One field was drilled after a wheat crop and the other field was aerially seeded. Camelina stands in the spring were spotty with areas with very good stands and few weeds while some lower spots had lower stands and many weeds, mainly field pennycress. To avoid seed contamination, field pennycress was hand weeded in both fields as much as possible. Both farmers were able to harvest about 20-30 acres each out of the 50 acres of camelina planted in the fall with an average yield of about 800 lbs seed/ acre. Seed harvested still had field pennycress seed so it was sent to a cleaning facility and the seed was cleaned to 99% purity using and optical sensor. Part of the seed was sent to Dr. Gesch and Dr. Lenssen for them to distribute among their farmers for fall planting (see below under Extension activities). Both North Dakota growers established winter camelina again in the fall of 2018, with the intent of double relaying soybean into green camelina in the spring.

3. An alfalfa-corn intercropping on-farm replicated trial was started in 2018 at the Anthony Thilmony farm in Valley City, ND. Three strips 20 ft wide and 100 ft in length were planted with corn, alfalfa or alfalfa +corn. The experiment had three replicates. The alfalfa variety was Vamoose RR. This variety was selected because it has leafhopper resistance. In the plot trials from 2016 and 2017 it was clear that alfalfa planted with the corn had increased leafhopper damage, probably because the conditions within the canopy were favorable for the leafhopper development. Using Vamoose solved this problem and this on-farm trial did not need insecticide spraying for leafhoppers. Corn was planted by the farmer at the same time as the rest of his corn field and then a 20ft drill from NRCS was used to plant alfalfa on the strips with corn (3 strips).

Results of this experiment were similar to what was observed in the plot trials across locations and years. Corn yield decreased by 27 bu/acre in the plot with alfalfa in it, although the difference was not statistically significant. This was expected since alfalfa planted at the same time as corn competes for water and nutrients with corn. Alfalfa established well under the corn canopy and plant density was not different from that of sole alfalfa. In thissystemthe loss of corn yield in Year 1 is offset by the 2.5 ton/acre gain in alfalfa yield in the following season.

Minnesota farms

1. Rollofson Farm:

In 2017, winter camelina and winter rye were seeded into replicated 15’ × 150’ strips of standing corn and soybean in late August using two different methods: 1) direct seeding with a high-boy seeder and 2) aerial broadcast seeding. Additionally, replicated strips of camelina and rye were direct seeded with a no-till drill into spring wheat stubble for comparison of establishment. Due to herbicide carry-over damage, no covers crops emerged in the soybean. In 2018, % green cover, total aboveground biomass, and pictures were taken to document establishment in the corn and direct-drilled wheat systems. The covers in the corn system were terminated in May prior to planting soybean. Equal amounts of cover and biomass were achieved with both camelina and rye in the direct seeded wheat system averaging about 554 kg ha^-1 in biomass production by May 7. In the corn system, rye provided better cover and biomass production averaging 221 kg ha^-1 than camelina which averaged 55 kg ha^-1 for direct seeding and 23 kg ha^-1 for the aerial seeding treatment. Direct seeding with the high-boy seeder generally resulted in better establishment than aerial seeding.

2. Martinson farm:

During the 2018 growing season, and on-farm site was established at the Martinson Farm in Rogers, MN. The Martinson Farm is a dryland farm on course-textured soil. Alfalfa variety Vamoose was established in strips with full season grain corn. Prohexadione was not used. Alfalfa did establish, however, during the hot dry 2018 summer, and void of irrigation, the alfalfa failed to survive. At corn harvest alfalfa populations were taken and there was less than 1 plant per 10 m². The trial was abandoned.