Agricultural soils are the greatest source of human
derived greenhouse gases to the atmosphere. Because of this a number of efforts
are underway to minimize the emissions of greenhouse gases from soils that include
use of organic fertilizers and no-till practices. Such mitigation practices, however,
require verification particularly at national and international levels where carbon
credits can be bought and sold. For this reason, we propose the development of an
autonomous soil gas flux chamber that, once deployed, automatically traps greenhouse
gases (CO2 and N2O) being released from soils to the atmosphere
for months at a time (an Automated Trace Gas-Trapping System or ATGTS). The ATGTS
consists of a flux chamber to collect gas evolving from soils, chemical or molecular
sieve traps to remove water and trap CO2 and N2O, a pumping
system that periodically turns on and off to move gases through the chemical traps,
a system for collecting and distributing rain-water within the flux chamber, and
a power system consisting of a solar panel and 12 V battery. We have previously
demonstrated that a prototype system is capable of quantitatively trapping CO2
and N2O gases evolving from soils and now seek to (1) design an independent
electronic control system and (2) finalize the mechanical design for an autonomous
system. We envision a final ATGTS system that could be sent to farmers and educators
across the country as a basis for them to participate in greenhouse gas accounting
programs.
