Research Abstracts Online
January - December 2011
University of Minnesota Twin Cities
College of Food, Agricultural, and Natural Resource Sciences
of Agronomy and Plant Genetics
PI: Nicholas R. Jordan
Microbial Associations of Nurse Crop Roots
This integrated research and extension project aims to lower barriers to establishment of diversified biofuel grassland agroecosystems. Such systems are emerging in importance, because they can function as highly “multifunctional” agroecosystems that provide a variety of ecological services in addition to biofuel production. Unfortunately, establishment of biofuel grasslands is often difficult, unpredictable, and highly vulnerable to interference and invasion by weeds. This group’s preliminary results suggest that interactions with soil microbes may help create these problems, because soil-microbial “legacies” of previous land use can inhibit growth of native grassland species, enabling weed invasion.
One promising option for cost-effective management of this problem is early establishment of “nurse” plant species that directly interfere with weed growth and which appear to change composition and function of soil microbial communities. These researchers are addressing important questions regarding nurse-species effects and weed invasion ecology in diversified grassland agroecosystems. They are using field and glasshouse experiments, and evaluate nurse-species effects relative to effects of a factor of known and strong importance, nitrogen supply, to answer the question of whether nurse species increase performance of native species relative to invasive species. In order to determine if nurse species change microbial composition of soils, the researchers are characterizing soil microbial populations using 454 and other sequencing and microbiological methods. Finally, they are trying to determine if it is possible to form an “agroecological partnership” that will integrate all biofuel project efforts, thereby producing site-specific knowledge to support biofuel grassland adoption by producers in Minnesota’s fuelshed regions.
Sheri C. Huerd, Staff