Location: Water Management Research
2013 Annual Report
Objective 2: Develop sustainable water management strategies for perennial horticultural crops with limited and impaired water supplies.
Objective 3: Develop sustainable agricultural water reuse systems to protect soil/environmental health of drainage impacted soils when using poor quality water.
Objective 4: (NEW) Develop effective, practical, economical, and environmentally acceptable approaches to replace methyl bromide as a pre-plant soil fumigant in ornamental and strawberry production systems. [NP303, C4, PS4A and PS4B]
Objective 5: (NEW) Develop various application methods, soil amendments, and physical barriers to reduce the emissions and enhance efficacy of the chemical alternatives to methyl bromide. [NP303, C4, PS4A]
Determine soil microbial structure following fumigation in ornamental and strawberry production systems using field trials and laboratory measurements . Use laboratory dose response studies to evaluate emerging chemicals as alternatives to methyl bromide for controlling pathogens and weeds. Determine pathogen and weed control efficacy of emerging chemicals as alternatives to methyl bromide in field trials. Test spot injection and spot plus carbonation as new fumigant application methods to enhance deep penetration in the soil for nematode control in orchard replant trials. Determine surface barriers with TIF tarp and reduced dosage for emission reductions and enhanced pest control efficacy in field trials.
Progress was made on systems to protect soil environmental health when using poor quality water. Field trials were established to grow salt tolerant varieties of canola on 5 acre plots on poor quality soils. A biofuel project has 20 acre plots of mustard planted on poor quality soil using rainfall and poor quality water as needed. A 20 acre field of mustard was established on excessively high saline and boron laden soils to evaluate their ability to survive and produce. In all plots, uptake and volatilization measurements were made to determine the amount of selenium (Se) removed from the Se-laden soil to a depth of 1 meter. Approximately 15% of Se net losses in the soil were accounted for in plant material and by volatilization, and approximately 30% was assumed lost by leaching from rainfall. Brassica seed yields were approximately 2 tons/acre and less than 1 ton/acre from Brassica plants grown on soils with soil salinity greater than 10 decisiemons per meter and a boron level greater than 10 milligram per liter. Seed processed for oils with an on-site oil press produced up to 160 gallons of biodiesel per 100 per acre. Field trials were expanded with salt and boron tolerant clones of cactus on drainage impacted soils.
To investigate nitrogen (N) emission losses as greenhouse gas nitrous oxide (N2O) from pomegranate fertilization treatments, field sampling methods and laboratory protocols have been fully established for measurement of N2O emission flux in the field. Preliminary data were collected for a full growing season in 2012 in a pomegranate orchard. Nitrous oxide production in the soil was sampled and determined during the growing season. The first year data showed clearly that N2O emissions from subsurface drip irrigation plots were much lower than surface drip, especially at higher N application rates. A positive linear correlation between the N2O emission flux and N2O concentration in soil-gas phase was identified. The first year data show that although fertilized agricultural soil is a major source of N2O emissions, significant emission reduction could be achieved by using subsurface drip irrigation.
Wang, D., Oshaughnessy, S.A., King, B.A. 2013. Automated irrigation management with soil and canopy sensing. In Q. Zhang and F.J. Pierce (eds.) Agricultural Automation - Fundamentals and Practices. Boca Raton, FL: CRC Press. pp. 295-321.
Banuelos, G.S., Schulin, R., Bitterli, C. 2013. Fate and movement of selenium from drainage sediments disposed onto soil with and without vegetation. Environmental Pollution. 180:7-12.