Project Number: 3611-12220-007-00
Project Type: Appropriated

Start Date: Apr 06, 2006
End Date: Apr 05, 2011

Objective:
1) Characterize the functional and population ecology of microorganisms involved in the degradation of herbicides, ecology of weed seed banks, and biogeochemical cycling of soil nitrogen, as these activities relate to the development of integrated weed management systems that employ more biologically based approaches. 2) Measure the effects of soil factors (which may be constant, dynamically fluctuating, or periodically recurring) that respond to agricultural management, natural climate and physicochemical conditions (including water/oxygen regime and fertility management) on the fate of herbicides.

Approach:
Proposed experiments will 1) investigate key populations of herbicide degraders under a variety of soil conditions, 2) determine the ecological (functional) significance of these populations in natural soil as they respond to changes in the environment, and 3) allow long-term temporal monitoring that will link microbial populations and their physiological response to management and seasonal/climate effects. The plan includes eight tasks, each of which addresses, in part, one or both project objectives. Two tasks (V and VIII) serve other ARS projects, one at another ARS location and the other part of a cross-location project. All tasks include laboratory measurement, however, Tasks II and VII involve treatments/variability imposed in the field. Treatments for remaining tasks will be introduced in the laboratory.