Location: Forage Seed and Cereal Research
Project Number: 2072-21410-004-06-I
Project Type: Interagency Reimbursable Agreement
Start Date: Sep 1, 2016
End Date: Dec 31, 2017
Loss of snow pack, changing hydrographs, and increased temperatures and irrigation demands as a result of climate change all threaten to create transformational drought for growers in the Pacific Northwest. One potential tool for mitigating drought is to amend soils with biochar produced from low-oxygen gasification or pyrolysis of organic wastes. Biochars increase soil moisture holding capacity, and in addition to other benefits, may persist in soil for decades to centuries. Our objective is to evaluate the potential for biochar soil amendments to mitigate drought impacts on agriculture at regional level, focusing primarily on dryland winter wheat. The first component of this assessment a laboratory characterization of biochar dosage-response in 12 regional soils, to determine the impact of amendment rate on soil hydraulic, and physical properties. A synthesis component will compare observations of biochar impacts to regional climate predictions, to assess the geographical regions in the PNW that are most likely to benefit from biochar amendment. Results of these studies will be used to develop a web-based Pacific Northwest Biochar Atlas, providing interactive maps showing the locations and results of biochar studies, locations of biochar producers and early adopters, providing calculators that can be used to estimate biochar impacts on moisture retention, and maps of projected changes in precipitation and temperature. Additional funds will support expanded monitoring efforts. In addition to the seasonal measurements collected at field sites, two sites will be instrumented to collect real-time soil moisture data. By coupling observations made in the soil with those made in the atmosphere, soil moisture dynamics in the field can be directly observed to determine, in real time, how biochar impacts soil moisture, and if this impact diminishes as biochar is weathered, with seasonal changes, or with more intense weather events. These continuous data will strengthen our statistical analyzes, validate model output, and improve characterization of biochar interactions with soil moisture.
We will follow a multi-step approach: 1. Soils will be sampled across 12 agricultural locations and analyzed for physiochemical and hydraulic properties. 2. Generate dosage-response curves to determine amendment rate impacts on hydraulic characteristics 3. Using regionally-downscaled CMIP5 predictions from the Integrated Scenarios of Climate, Hydrology, and Vegetation for the Northwest Project, we will classify agricultural sub-regions on the basis of changes in stream flow and precipitation, and convolve these water supply predictions with our observations of soil moisture retention changes from biochar amendment. We will draw on observations from our study as well as other biochar studies in the PNW. 4. Develop a decision support model to communicate the impact of biochar on soil moisture.