2007 Annual Report 1a.Objectives (from AD-416) The objective of this cooperative research project is to investigate soil microbial diversity and community structure in dryland ecosystems. 1b.Approach (from AD-416) In consultation with WSU scientists, soil microbial diversity indices and community structure patterns will be developed, and field and laboratory experiments will be designed and conducted in order to test hypotheses and determine parameters for this research. Consultation with and review by other researchers and users will ensure the research meet the specified needs. Results of this research will be jointly reported in the scientific literature and in outreach efforts to growers and field personnel. Documents SCA w/ WSU.Formerly 5348-11120-002-02S (5/06). 3.Progress Report This report serves to document research conducted under a specific cooperative agreement between ARS and Washington State University titled ‘Soil microbial diversity and community structure in dryland ecosystems.’ Additional details of research can be found in the report for the parent project 5348-11120-004-00D titled ‘Soil conservation systems for sustainability of Pacific Northwest agriculture.’ The objective of this cooperative research project is to investigate soil microbial diversity and community structure in dryland ecosystems. ARS scientists in the LMWC Unit at Pullman, WA in collaboration with Washington State University scientists assess soil parameters in dryland agriculture. Microbial communities determined by phospholipid fatty acid methyl ester and substrate utilization analyses differed between no-till and traditional tillage systems. Although the change was slow, no-till soil microbial community and soil organic carbon were approaching that found in native undisturbed sites. Results show long-term cumulative benefits of no-till vs. traditional tillage on soil quality; this information will provide growers and scientists with practical advice to aid in the development of management practices and agricultural policy. This specific cooperative agreement was assessed through regular meetings and site visits. 4.Accomplishments None 5.Significant Activities that Support Special Target Populations None