OBJECTIVES: 1) Continue ongoing work to diversify weed approaches by studies of management interventions at several spatial and temporal scales, with emphasis on elucidating the role of plant-soil interactions in plant invasions and in invasive plant management. 2) Develop a "knowledge network" to support diversification of corn-soybean cropping systems by adoption of various "third crops", and conduct scholarly evaluation of this project and similar work in engaged science. 3) Participate as agroecologist in large-scale collaborative efforts to develop diversified agroforestry systems for production of biobased materials, renewable energy and environmental benefits in S. Minnesota.

APPROACH: 1) Role of plant-soil interactions is being examined by greenhouse studies using various soil inoculants to compare native and invasive/weedy by assessing reciprocal effects of plants and soil biota. Other invasive plant studies are using population and physiological ecology methods to assess weed responses to various management approaches. 2) A set of profession-specific workshops and collaborative learning groups will be organized and delivered. Learning groups will be organized around specific "third crop" projects, e.g., ongoing efforts at market development. 3) Agroecological function of diversified agroforestry systems will be assessed using hydrological, agronomic, soil-science and wildlife-management methods in large-scale collaborative projects; focusing on medium to large-scale demonstration sites.

KEYWORDS: integrated pest management; diversification; agroforestry; biodiversity; ecosystem management; ecosystems; mycorrhizae; soil plant relations; invasive species; plant ecology; weeds; learning; grasslands; grain; spatial distribution; temporal distribution; intervention; corn; soybeans; weed control; cropping systems; renewable resources; resource use; environmental effects

PROGRESS: 2006/01 TO 2006/12
Our research program in agricultural ecology centers on the use of biological diversity to support sustainable development of agriculture. During the past year, we have focused on the following areas of effort: A new approach to sustainable development of more diversified cropping systems, driven by 'eco-social feedback' between an agricultural production system that produces 'positive externalities' (i.e., beneficial effects on water quality and wildlife) and a group of social actors who capture value from these externalities and provide material support for additional development of the production system. With collaborators, we are developing an agent-based model simulation framework to explore this hypothesis in the context of management-intensive rotational grazing systems. This sustainable-development model depends on collective learning and action by multi-stakeholder groups. As an essential 'laboratory' for developing this hypothesis, we have continued to co-organize such groups to promote sustainable grazing systems in the Chippewa River Watershed of west-central MN, and to promote sustainable biofuel production from perennial cropping systems around Madelia, MN. Work in the Madelia project has focused on GIS-based landscape design work to create a number of alternative scenarios for multifunctional perennialization of current agricultural landscapes around Madelia, in support of economically, socially and environmentally sustainable biofuel production. We have now developed a successful adaptation of DNA-based methods for assessment of arbuscular-mycorrhizal fungal diversity and community composition via 'community profiling' techniques. We are currently applying the method to characterize results of a two-year field experiment on relations between plant and AMF diversity and community invasibility in mixed-grass prairie plant communities. An emerging focus for this work is an emerging cropping system of fundamental future importance: diversified grassland agroecosystems for biofuel production, which aim to use native plant biodiversity to provide a variety of ecological services in addition to biomass production. Continued work on interactions between soil microorganisms and invasive plants has addressed interactions between two invasive exotic species (leafy spurge and garlic mustard) with both beneficial and pathogenic soil microbiota. Occupancy by the invasive species appears to leave a microbial legacy after effective spurge control; this 'legacy' effect appears to interfere with subsequent restoration and management of desirable vegetation, including native species. We are seeking cost-effective methods to restore soil conditions, based on use of certain native species which appear to have high ability to colonize soils previously occupied and altered by invasive species, and to initiate a process of soil restoration.

IMPACT: 2006/01 TO 2006/12
There is now widespread interest in rural communities and among agricultural and environmental groups in development of more diversified agricultural landscapes based on increased use of perennial plant species, but many barriers stand in the way. Our research program focuses on the efficient use of biological and social resources to surmount these barriers by reducing the cost and risk of adopting more diversified and perennial-based forms of farming.

PUBLICATIONS (not previously reported): 2006/01 TO 2006/12
1. Jordan, N., Niemi, H., Simmons, S. Becker, R., Gunsolus, J. and White, S. 2006. Knowledge networks for implementation of integrated weed management: principles and practical guidelines. In R. K. Kohli (ed.). Handbook of Sustainable Weed Management, Haworth Press, pp. 825-854.
2. Jordan, N., Neimi, H., Simmons, S. White, S., Gunsolus, J., Becker, R., Damme, S. 2005. A knowledge network for sustainable weed management: an experiment in public scholarship. In. S. Peters, N. Jordan, M. Adamek, (eds.). 2005. Taking the College to the People: The Practice of Public Scholarship in the American State and Land-Grant University System. Kettering Foundation Press.

PROJECT CONTACT:
Name: Jordan, N. R.
Phone: 612-625-3754
Fax: 612-625-1268
Email: jorda020@umn.edu