2009 Annual Report 1a.Objectives (from AD-416) 1. Determine new water requirements and develop improved management practices and systems for irrigated crops to promote efficient resource use and water quality protection. 2. Develop sustainable agronomic systems for water reuse strategies and for bio-remediation of soils impacted by use of saline water containing high concentrations of boron and trace elements. 3. Develop and evaluate improved drainage design and irrigation, drainage, and vegetation management methods to reduce water and pollutant discharge from irrigated agriculture to preserve quality of agricultural soils and ground water. 1b.Approach (from AD-416) Use weighing lysimeters and precision water and nutrient application through micro irrigation systems to assess water, nutrient, crop yield and quality, and deep percolation relationships for annual crops and perennial horticultural crops. Determine shallow groundwater contribution to water requirements of currently used crops and new species using large weighing lysimeters. Use field studies to develop sustainable cropping systems in areas with restricted drainage discharge, and to determine the impact of management practices on soil salinity, groundwater and drain water quality and quantity, and crop yield. Determine, through greenhouse and field studies, the ability of crop species to tolerate and accumulate selenium, boron, and other constituents found in arid saline soils and shallow groundwater. Formerly 5302-13000-009-00D (12/06). 3.Progress Report A broccoli crop was planted in September 2008 and was hand harvested in January 2009. The broccoli heads were separated by size and the response to irrigation was determined based on head size and weight and number of heads in the harvested area. These data were summarized and sent to the PWA biometrician for analysis. The data from 2008 along with the data from 2002 are being analyzed for use in a publication. The column lysimeters are being used to determine the crop water use from shallow ground water by Alkar wheat grass as a function of depth to water table and the electrical conductivity of the groundwater. This system is partially automated to measure changes in weight of the lysimeter and to control the irrigation. The large weighing lysimeters and the surrounding field are being prepared for the planting of pomegranate that will be used to determine the water requirements of a developing pomegranate plant. Different plant and tree species have been evaluated for their ability to tolerate irrigation water high in salinity, Se and B. These include: canola, mustard, sunflower, safflower, salado grass, cord grass, hybrid poplar trees, and cactus. Plant samples were analyzed for trace element accumulation, including selenium (Se) and Se volatilization measurements were performed on the smaller plant species throughout the growing season. Movement of selenium, boron, and salinity originating from drainage sediment was monitored and analyzed to a depth of 2 meters over a period of 6 years. Production of new products from plants irrigated with poor quality water is presently being evaluated. These include bio-fuel, selenium-enriched feed meal, bio-fumigants, and Se-enriched prickly pear fruit. A dairy feed trial was conducted by feeding Holstein and Jersey cows Se-enriched canola meal produced from plants used as recipients for poor quality water. Se-enriched mustard meal was tested as a bio-fumigant in strawberry production. In addition, canopy temperature measured with thermal infrared sensors was used as a guide in a deficit irrigation study on mature peach trees. The trees were fully irrigated prior to harvest with deficit irrigation strategies being implemented following harvest. The strategies employed included withholding irrigation for a set period of time and then fully irrigating, irrigation at 25% of measured crop water use, and irrigating when the trees reached a predetermined stress level. Irrigation systems used included furrow irrigation, micro-sprinklers, and subsurface drip. 4.Accomplishments 1. Selenium Remediation Using Biofuel Crops. Selenium in the soil environment is toxic at high concentrations. ARS scientists in Parlier, CA, identified plant species and poplar tree clones that were more adapted to sustaining drainage water reuse strategies and for growing in areas with underlying poor water quality in the Westside of the San Joaquin Valley of California. With the oil plant species, we produced bio-based products from 1.5 tons of seed/acre that have economic value for the grower, e.g., bio-fuel and Se-enriched feed products after extracting the oil from the seeds with our on-site oil press, while poplar trees were annually cut and cuttings were considered for gasification uses. These findings improve our ability to sustainably use an agronomic-based system as part of the overall drainage water reuse strategy, and encourage its widespread usage in the problematic regions of central California. 2. Plant Enriched Selenium for Animal Feed. There is general lack of selenium in animal feed. ARS scientists in Parlier, CA successfully increased milk Se concentrations in Holstein and Jersey cows fed Se-enriched meal produced from canola used as a recipient for poor quality water. We have also determined that increases of extractable selenium occur over time in soils used as disposal site for drainage sediment; hence downward movement of soluble selenium was observed. The research related to production of bio-fuel and Se-enriched feed and food products were published as a chapter in a book on “Bio-fortification and development of new agricultural products." The study showed potential of converting a water-quality problem to a beneficial end use for society. 3. Infrared Canopy Temperature for Guiding Deficit Irrigation in Peach. Deficit irrigation is a management method to conserve water resources and energy associated with delivering the irrigation water to the farm by only supplying the amount of water necessary to meet crop demands. Canopy temperature, as an indicator for water stress, was measured by ARS scientists in Parlier, CA using thermal infrared sensors (IRT) in a peach orchard. Results showed that average maximum canopy temperature was significantly higher in treatments that received deficit drip and furrow irrigation than treatments received full irrigation. Deficit irrigation saved over 50% water and there was no significant impact on peach yield and quality. The study clearly demonstrated that infrared canopy temperature can be used as an onsite guide for managing deficit irrigation in orchard crops. 6.Technology Transfer Number of Web Sites Managed 1 Review Publications Banuelos, G. Z.Q. Lin.2009. Development and Uses of Biofortified Agricultural Products. CRC Press, Boca Raton, FL. 57-70. Banuelos, G. Chapter 4. Phytoremediation of Selenium Contaminated Soil, and Water Produces Biofortified Products and New Agricultural Byproducts. p. 57-70 in Banuelos, G. and Z.Q. Lin (eds.) Development and Uses of Biofortified Agricultural Products. CRC Press, Boca Raton, FL. 2009. Banuelos, G. J.J. Stapleton. 2009. Value-added Sustainability: Energy Crops for Biological Disinfestation and Remediation of Soils. California Agriculture. 63:41-46. Ayars, J.E. Water requirement of irrigated garlic. Proceedings of the American Society of Agricultural and Biological Engineers International (ASABE)51(5):1683-1688, 2008.