Does a C3-C4 forage mix simultaneously improve forage production and carbon sequestration?

View the project final report

• 2007 annual report
• 2008 annual report

Commodities

• Agronomic: general hay and forage crops, grass (misc. perennial), hay

Practices

• Animal Production: feed/forage
• Education and Training: on-farm/ranch research
• Natural Resources/Environment: biodiversity, carbon sequestration
• Production Systems: agroecosystems, holistic management

I seek to improve understanding of ecosystem support, provisioning, and regulating services provided by pasture ecosystems in the Upper Midwest. Collaborating with three grass-based farmers who are conducting experiments on their lands, I will evaluate forage quantity and quality as well as C sequestration potential under a gradient of C3 to C4 grass ratios. This information will help grass-farmers to reap the economic benefit of C4 forage production during the hot summer months when C3 forage production wanes. This work will provide much needed understanding about C3 pastures and the benefits of re-storing native grasses to working lands. Products will include peer-reviewed publications, an Agroecology MS thesis, and presentations at field-days, conferences, and to interested conservation-research groups. Outcome indicators include a successful defense of a Master thesis in Agroecology.

We expect as short-term outcomes:
• To assess forage quality and quantity in pastures under a C3:C4 ratio gradient.
• To understand the trade-offs between forage quality and quantity when introducing native grasses to existing pastures.
• To evaluate changes in the C sequestration potential of these pastures by quantifying above- and below-ground net primary production and microbial respiration.

Intermediate outcomes will include:
• Increase the ability of the grass-farmer to reap the economic benefit of forage production during hot summer months when cool-season forages (C3) are quasi-dormant, and
• Promote the establishment of native plant species from the tallgrass prairie (C4) into working lands.

As a long-term outcome, the results of this project should promote land stewardship by blending management for livestock production with conservation techniques. Once the environmental and agronomic benefits of incorporating native, C4 grasses into C3-dominated pastures are better understood and documented, farmers will be more likely to adopt such practices.