Earthworms and Carbon Cycling in Agricultural and Rangeland Soils of the Inland Pacific Northwest
Environmental conditions influence, to a great extent, the type of cropping practices and productivity of agricultural systems across regions. Management practices that promote soil conservation, for example, may be profitable in one climatic zone but may not be successful in another. To better understand how climate interacts with management, we will study the impact of conventional and conservation management practices on two related indicators of soil quality- earthworms and soil organic matter (SOM) across a climatic gradient that defines the wheat producing region of the Inland Pacific Northwest (IPNW). Sites with paired conservation and conventional management practices (till and no-till, for example) will be located in each recognized climatic zone across the region. Soil samples will be collected at the same time that earthworms are
sampled. General soil characterization will be carried out in the laboratory and earthworms will be counted, weighed and identified to species and/or functional groups. Earthworm density and diversity will be related to both climate and management. Limitations to earthworm activity will be determined by analyzing data collected from across the region. Soil samples will be analyzed to determine trends in SOM that may be related to climate, management and, potentially, earthworm activity. A similar, but scaled back approach will be taken to understanding SOM dynamics in differently managed rangeland systems within the state of Idaho. Overall this project will produce data that can be used to develop climatic-zone appropriate management practices that promote SOM storage and long-term soil quality.