The goal of this research is to develop alternative ‘in-row’ weed management practices that both provide effective weed management, do not negatively impact grapevine growth and juice, and improve soil nitrogen (N) retention by minimizing inorganic N leaching and nitrous oxide (N2O) emissions. The establishment of ‘in-row’ treatments was initiated in October 2009. Greenhouse gas emissions (N2O and carbon dioxide, CO2) were collected bimonthly, and C and N dynamics in response to events that increase greenhouse gas emissions were measured from October 2009 to the present. These measurements will continue through the study’s third year. Preliminary findings indicate that ‘pulse’ events such as cultivation, compost addition, fertigation, irrigation and rainfall are major periods of greenhouse gas emissions. When cultivation occurred just after compost addition, N2O and CO2 emissions increased and were greater than the cover crop and herbicide treatments. When rainfall occurred immediately after this cultivation, N2O and CO2 emissions were also greater than the other treatments, highlighting the interactive effects of management (i.e., cultivation and compost) and rainfall on greenhouse gas emissions. When treatments were irrigated, both N2O and CO2 were greatest from the cultivated treatment, followed by the cover crop and herbicide treatments, respectively. Although the cultivated treatment emitted more GHGs, further analysis will determine the net carbon footprint of each respective treatment. The cover crop and herbicide treatments tended to have greater nitrate leaching than the cultivated treatment. Temporal dynamics of leaching differed among treatments, suggesting that management practices could be adjusted over time to minimize these losses. Data from this study will be incorporated into the GRACEnet (Greenhouse gas Reduction through Agricultural Carbon Enhancement network) database to develop predictive models of greenhouse gas emissions in response to agricultural management. GRACEnet is a national network of USDA/ARS scientists who develop “…agricultural practices that will enhance carbon sequestration in soils, promote sustainability and provide a sound scientific basis for carbon credits and trading programs work on greenhouse gas emissions in agricultural operations across the nation”. This project compliments the study funded by the CDFA Specialty Crops Block Grant program (SCBG) (“Reducing Our Footprint: Minimizing Greenhouse Gas Emissions and Nitrogen Leaching in Vineyards, and Enhancing Landscape Carbon Stocks”). Furthermore, findings from this study will be included in the development of an interactive process model for grower use assessing GHG emissions associated with different management practices, a project that was recently awarded to the California Sustainable Winegrowing Alliance by CDFA SCBG (“Field Testing a Carbon Offset and Greenhouse Gas Emissions Model for California Wine Grape Growers to Drive Climate Protection and Innovation”).
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF2010-10-16 06:23:252017-10-16 06:24:24Developing Sustainable ‘In-Row’ Management Practices for Improving Weed Management and Soil Nitrogen Retention