Submitted to: Journal of Plant Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2007
Publication Date: 10/1/2007
Citation: Ginting, D., Arnold, S.L., Arnold, N., Tubbs, R.S. 2007. Construction and testing of a simple and economical soil greenhouse gas automatic sampler. Journal of Plant Nutrition 30:1441-1454. Interpretive Summary: Measuring greenhouse gas production requires many samples being taken to account for field variability. Manual sampling is generally used to accomplish this, but requires a lot of people to meet timing demands at multiple sites. An automated gas sampler was constructed and the results compared to manual sampling techniques. Carbon dioxide levels typically measured in eastern Nebraska corn fields were duplicated in a sealed chamber to test the automated sampler. Automated and manual techniques were used to take gas samples from the chamber at 0, 5, and 10 minute intervals. Samples taken by the automated system were transferred to pre-vacuumed vials after one hour. Carbon dioxide was increased while leaving syringes attached to the chamber. The automated sampler had as good of results as manual techniques and reduced labor.
Technical Abstract: Quantification of soil greenhouse gas emissions requires considerable sampling to account for spatial and/or temporal variation. With manual sampling, additional personnel are often not available to sample multiple sites within a narrow time interval. The objectives were to construct an automatic gas sampler and to compare the accuracy and precision of automatic versus manual sampling. The automatic sampler was tested with CO2 fluxes that mimicked the range of CO2 fluxes during a typical corn-growing season in eastern Nebraska. Gas samples were drawn from the chamber at 0, 5, and 10 minutes manually and with the automatic sampler. The three samples drawn with the automatic sampler were transferred to pre-vacuumed vials after one hour; thus the samples in syringe barrels stayed connected with the increasing CO2 concentration in the chamber. The automatic sampler sustains accuracy and precision in greenhouse gas sampling while improving time efficiency and reducing labor stress.