This document provides instructions for creating a manual for operating a Lachat instrument to analyze total nitrogen content in soil samples. It describes the purpose of the Lachat as finding the ammonium and nitrite content to determine total nitrogen. It then summarizes the standard process for sample and standard preparation, instrument warm up, running samples, monitoring the run, data collection and post-run cleaning. Potential hazards of chemicals used are also listed, along with required personal protective equipment. Applications for the method include a university lab and agricultural soil treatment studies.
4. Purpose
• To find Total Nitrogen Content by analyzing
Ammonium and Nitrite content in Soil using
Flow Injection Analysis
5. Summary of Process
• Wear gloves, goggles and coat
• Take out samples, standards, qc and reagents to thaw
• Warm up Lachat, and clean lines
• Pour samples and standards into tray and enter into Omicron
• Make reagents as needed
• Place lines into reagents
• Start Lachat and monitor the run
• At end of run summarize data
• Wash lines and shut off Lachat
9. Anaerobic Soil Disinfestation (ASD)
for suppressing Verticillium dahliae in
CA strawberries
• C. Shennan1, J. Muramoto1,, M. Bolda4, S. T. Koike4,
• O. Daugovish4, M. Mochizuki4, K. Klonsky5, E.
• Rosskopf3, N. K. Burelle3 , D. Butler2,3 , S. Fenimore5
• and J. Samtani5
• 1Univ. of California, Santa Cruz,
• 2Univ. Tennessee
• 3USDA-ARS, U.S. Horticultural Research Lab, Florida,
• 4Univ. of California Cooperative Extension
• 5 Univ. of California, Davis
• Funded by USDA-CSREES MBTP 2007-51102-03854 and CA Strawberry
Commission
10. ASD: Background
• Developed as alternative to Methyl bromide fumigation
• in Netherlands (Blok et al., 2000; Doug et al., 2004) and
• Japan (Shinmura & Sakamoto, 1998; Shinmura, 2000,
2004)
• Controls range of soilborne pathogens and nematodes
• across a range of crops
• In Japan, used by hundreds of farmers in greenhouse
• production (small scale)
11. ASD: Three Steps
• Incorporate organic material
• Provides C source for soil microbes
• Irrigate to saturation
• Water-filled pore space
• Cover with oxygen impermeable tarp
• Create anaerobic conditions and
• stimulate anaerobic decomposition of
• incorporated organic material
12. ASD: Mechanisms
• —Accumulation of toxic products from anaerobic
decomposition (e.g. organic
• acids, volatiles)
• —Biocontrol by anaerobic microorganisms
• —Low pH
• —Lack of oxygen
• —Combination of all of these
