2012 Annual Report
1a.Objectives (from AD-416):
1. Develop sustainable water management strategies for wine, table, raisin, and juice grape production using limited water supplies.
2. Develop sustainable water and soil management strategies for minimizing the impacts of drought and salinity on the root zone environment, grape yield and quality.
3. Quantify the effects of various water management strategies on fruit and product composition, and sensory qualities.
1b.Approach (from AD-416):
This research will be conducted using both laboratory and field research sites. The field research will be conducted in the Central Valley and Paso Robles, California. Laboratory studies will be conducted at the U.S. Salinity Laboratory in Riverside, California.
The project is related to objective 2 of the parent project 5310-61000-016-00D, Objective 2: Improve our ability to predict the impact of degraded waters on infiltration into soils and plant response to irrigation with these waters. In the second year of the experiment we conducted two salinity surveys at each of the three sites, two are in wine grape production with no leaching during the growing season and variable winter leaching. The imposed leaching treatments consisted of two quantities of leaching water applied by sprinkler or drip irrigation. During this past year we conducted two salinity surveys at each site, one after winter leaching and the other after harvest in the fall. At each site we collected soil samples with depth for each of the treatments and replicates. We also conducted a detailed 2-D electrical resistivity survey. Samples were analyzed for major ions and salinity as per experimental plan. Preliminary results from the multi-year experiment indicate that winter leaching reduces the upper profile salinity but the extent of leaching is much lower than expected with 30-40 cm of leaching water applied. The third site is in Southern California, with table grape production. Management of table grapes requires more water as the objective is large hydrated fruit for the fresh market. Soil was collected from this site before and after leaching treatments and a salinity survey was conducted. Although more water is applied at this site than at the Central Coast sites in San Luis Obispo County, California, salinity levels are comparable after the growing season, consistent with application of Colorado River Water and high evapotranspiration at the table grape site. The leaching treatments show a large reduction in salinity with leaching in this loamy sand soil. Preliminary data suggests that leaching with sprinklers is more effective then leaching with drip irrigation. This research is directly related to development of best management practices for the grape industry for salinity control. The research will contribute to development of new recommendations, thus contributing to the NP211 program.
Communication was via emails, accomplishment reports, phone calls, and on site cooperative/ARS meeting.