Changing markets, technology, and attitudes are creating opportunities for new paradigms
supporting wider adoption of soil-building practices, but there is little science-based information
about integrating livestock and cover crops into irrigated crop rotations. While a few producers
in the sugarbeet/malting barley production area of northwestern Wyoming and south central
Montana experiment with cover crops following barley harvest for soil cover and livestock
forage, uncertainties about costs and benefits, and how to navigate options, mean that intensive
tillage and expansive bare soil are still the norm in this region. To address questions about effects
of different cover crop options on subsequent cash crops, soil quality, forage yield and quality,
and farm economics we will establish an on-station trial in a producer-driven long-term rotation
experiment at the University of Wyoming Powell Research and Extension Center, an on-farm
experiment with at least five producers, and innovative education programs and products. We
will evaluate four types of cover crops following barley in systems where sugarbeet is the
subsequent crop. Cover crop types include volunteer barley regrowth, replanted barley, soil
building mix, and livestock production mix. The on-station experiment will be embedded in the
long-term rotation experiment where half of each cover crop plot will remain unharvested and
half will be harvested for hay. The on-farm experiments will be established after harvest of
irrigated barley where producers winter graze replanted barley. On-farm plots will be split, with
half ungrazed in 0.1-acre exclosures and half winter grazed with the rest of the field. The
participatory research will creating settings for farmer inquiry, peer-to-peer learning, and lasting
relationships. We will optimize those opportunities by 1) expanding our technological exchange
created for the long-term rotation experiment; 2) field-based hands-on workshops; 3) Extension
and research publications; and 4) impact evaluation with on-going responsive adjustments to
research and extension activities.
This project will provide producers with knowledge to implement soil-building practices for
more sustainable irrigated cropping systems. Specific objectives include quantifying and
comparing effects of four types of cover crops (volunteer barley, replanted barley, and two cover
crop mixes) and three residue treatments (hay, grazed, and no harvest) on:
1. Yield and quality of subsequent crops;
2. Soil quality and organic matter cycling;
3. Forage quality and quantity of the four cover crop types;
4. Water use efficiency in subsequent sugarbeets;
5. Costs and benefits of different cover crop/forage options;
A cover crop mix planted after barley harvest in sugarbeet-barley rotations will improve soil quality compared with no cover crop and with replanted or volunteer barley regrowth. Further, soil quality improvements will vary with management of cover crops for green manure, hay, or grazing.
During the 2018 growing season we established cover crop plots on six farms and on the University of Wyoming Powell Research and Extension Center (PREC) at Powell, WY, based on decisions made at a project kick-off meeting held on May 30, 2018, and attended by most of the farmers, educators, and researchers on the project team. At the meeting we settled on one cover crop mix to compare with replanted barley and with volunteer barley regrowth. The cover crop mix includes four species but no grass species in order to keep producer’s options open to plant a small grain following the cover crop, and because volunteer barley with act as a grass component.
Graduate student Taylor Bush worked with the farmers to locate and establish plots at each farm, and with the PREC farm crew to plant the on-farm and on-station plots. The on-station plots were established within a long-term crop rotation study with two tillage and two irrigation-level treatments. Plots were planted and grazing exclosures established as per the study design in the project proposal. Taylor collected and analyzed dynamic soil properties at barley harvest and at freeze up at all plots, and collected cover crop/barley biomass at freeze up. Stable soil properties are currently being analyzed on those samples. He collected soil trace-gas emission samples in the summer and fall seasons, and will collect winter samples January 18, 2019, from the PREC plots.
The data collected so far represents baseline information on the soils from each field. Therefore no conclusions can be drawn at this point in the project. As expected, values for potentially mineralizable carbon and nitrogen (which were presented as a poster at the 2019 Soil Science Society of America meetings) were quite low, indicating depleted soils of intensively farmed beet-barley rotations. Other data and samples are still being analyzed.
We have begun to develop the “network for technological exchange” described in the proposal, with the initial kickoff meeting and ongoing communication with cooperating producers, educators, and researchers. We have begun planning mini-field days and field workshops for 2019 and 2020. We did not hold field days or workshops in 2018 because some aspects of project implementation remained uncertain until too late in the season (in particular the planting success of the cover crops) to plan those events. Next year we are confident in the success of the plots so that meaningful educational events can be planned.
Educational & Outreach Activities
Posters on the project were presented at the PREC field day and at the Soil Science Society of America meeting.
- Cover crop establishment, composition, and management was discussed in depth at the meeting on May 30, 2018. All the farmers, researchers, educators, and students learned a great deal from one another.
Cover crop selection, establishment, and management.
Outcomes of the project will provide information on how to integrate cover crops and grazing or haying into crop rotations in ways that will add addition revenue streams while improving soil quality and agroecosystem biodiversity.
The farmers we are working with on this project are progressive in that they are already utilizing some form of conservation tillage, cover crops, and livestock integration. But they’re practices and experiences vary a great deal, so having them all in the same room each year to discuss the project with researchers, educators, students, and others is extremely valuable to all of us.