SOW_cyliners and gases.docx

TITLE:

Quantification of greenhouse gas emissions from irrigated drill seeded systems

OBJECTIVE:

1. To quantify total area- and yield-scaled N2O, CO2, and CH4 emissions from row crop fields using vented chamber method and fully automated gas chromatography system.

APPROACH:

The regular purchase of high-quality special blend and carrier gases is crucial to support research projects on greenhouse gas emissions (GHG) from row crops. The vented flux chamber method coupled with gas chromatography will be used to quantify emissions of CO2, N2O, and CH4 from soil trace gas collected at weekly intervals throughout rice crop cycle in various experimental fields. Analyses of atmospheric gases such as CO2, N2O and CH4 concentrations will be conducted using the GC2014 and GC2030 automated gas chromatography (GC) systems equipped with ECD, FID, TCD detectors. Ultra-high-quality helium, zero-grade air gas, P5 and hydrogen gases in 300 and 200 tank sizes with 99.999% purity will be used to continuously run the GC. Standard certified special blend of gases are also needed to calibrate the GC instruments. Table 1 summarizes the description and frequency of support gases and calibration gases needed for the analyses of CO2, N2O and CH4 throughout the rice crop cycle (annual measurements).

Table 1. Summary of carrier gases and calibration gases needed to analyze atmospheric gases from experimental fields.

Continuous supply of high-purity support gases and high accuracy calibration gases from the same source ensure the high quality GHG emission datasets. The same high purity gases are needed to maintain the high sensitivity and accuracy of GC detections from all three detectors.

DELIVERABLES:

This work provides high quality GHG emissions with minimum error of estimates from chamber method and GC instrument. It ensures high repeatability and the lowest coefficient of variance within each range of calibration gases and during span calibration.