Maintaining Kernza intermediate wheatgrass grain yields overtime in organic and conventional systems in WI

View the project final report

Commodities

• Agronomic: grass (misc. perennial)

Practices

• Animal Production: feed/forage, pasture fertility
• Crop Production: cropping systems, fertilizers, nutrient management, organic fertilizers
• Education and Training: display, extension, networking, on-farm/ranch research, participatory research, technical assistance
• Natural Resources/Environment: soil stabilization
• Production Systems: agroecosystems, organic agriculture
• Sustainable Communities: local and regional food systems

The main project outcome is to demonstrate an organic and conventional agronomic management practice in farmer fields in WI to maintain grain yield over time. In 2021 and 2022, similar research experiments were performed at UW-Madison research stations using a conventional practice, thinning with herbicides, to remove Kernza IWG rows. Because many Kernza IWG farmers use organic management practices, this project also uses an organic practice, tillage, to remove Kernza IWG rows. The experimental sites are two farms in Wisconsin in their third season of Kernza IWG production. Ross Bishop is the conventional no-till farmer located in Washington county, and Halee and John Wepking are beginning organic farmers located in Iowa county. 

The approach is to use the optimal level of stand thinning demonstrated at the UW-Madison research sites for maintaining grain yield. At the organic site, a Subsoiler will disrupt roots with minimal surface disruption to thin the Kernza IWG stand. At the conventional site, rows will be thinned using herbicides. The two treatments, no thinning and thinning, will be replicated four times per site. The experimental fields will be fertilized with nitrogen in the spring of 2023, monitored through the summer, and harvested in late summer 2023. 

The project will be evaluated using data collected during the 2023 field season. Plant height and plant growth stage will be monitored throughout the summer of 2023. Grain yield, forage yield, and weed biomass will be harvested in the late summer of 2023. All samples will be weighed and dried, and grain will be threshed and weighed using a mechanical thresher at the UW-Madison West Madison research station. Dry weights will be used to run ANOVA and Tukey HSD tests at a 0.05 significance level to detect treatment effects and mean differences. 

Results will be published in Agronomy Journal and communicated to the farmers through the Midwest Forage Association newsletter. The results of this experiment will provide Kernza IWG farmers with recommended agronomic management practices to maintain their grain yields overtime, addressing a major concern with Midwest producers. If this project shows similar results to the research station trials, it will provide even more evidence that a simple agronomic practice can extend the life of an economically viable Kernza IWG stand by maintaining grain yield overtime. In turn, this can increase the profitability and longevity of a field of Kernza IWG.

This project primarily addresses Kernza IWG farmers in the North Central Region and secondarily addresses the surrounding community. The primary learning goal is to provide Kernza IWG farmers with evidence and education that thinning stands reduces intraspecific competition and maintains grain yields overtime. If this practice is adopted, the learning outcome should increase profitability of Kernza IWG systems from higher grain yield and stand longevity. This outcome will occur through extension publications and updated agronomic management practice recommendations provided to producers from the Land Institute.

The primary action outcome is that farmers will adopt the management practice of thinning their stands to the recommended level to maintain grain yields. This will be evaluated through on-going surveys that ask farmers about their agronomic management practices to maintain grain yield, whether or not they adopted the thinning practice, and the results of, or barriers to, adoption. This will directly evaluate the project success and direct future research and communication to address farmer needs. 

The secondary learning outcome is that the surrounding community including other Kernza farmers will learn about Kernza IWG and the on-going research between local farmers and the university through field days, elementary-school farm visits, social media, and publications. Long-term, this will help foster a stronger local food system and introduce potential consumers and farmers to the environmental, social, and economic benefits of Kernza IWG.