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En1320 Unit 9 Lab Report

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The N2O and NO fluxes measurements were conducted in 2–28 days intervals during the growing season and 10-30 days intervals during the non-growing season and between 8:00 and 11:00 h each measuring day to minimize the effect of diurnal temperature variation. The stainless steel chamber (40 cm in diameter and 30 cm high) was used for the measurement (Toma and Hatano, 2007). Gas samples were taken from the chambers using a 50 mL syringe. The samples N2O were collected for 0; 15 and 30 minutes and for 0 and 30 minutes for NO samples. N2O was analysed using gas chromatography with ECD (GC-2014 Model, Shimadzu) and NO using NOx Analyser (265 P Model, Kimoto Electric, Osaka, Japan). Gas flux is the gradient of gas concentration in chamber over time. The cumulative gas flux was calculated by ∑_(i=1)^n▒Rix24xDi Hence, Ri is the mean gas flux (mg/m2/hour) of the two successive sampling dates, Di is the number of days in the sampling interval and n is the number of sampling times. …show more content…

A 10 g of fresh soil in 100 mL conical flask was incubated under anaerobic condition with an addition of different solutions. The solutions consisted of 1 g/L of chloramphenicol for four treatments, 1) distilled water (Ctrl), 2) glucose of 300 mg C/L (+C), 3) KNO3 of 50 mg N/L (+N), and 4) glucose of 300 mg C/L + KNO3 of 50 mg N/L (+C+N). The flasks were evacuated and flushed four times with N2 to ensure anaerobic conditions, and acetylene (C2H2) gas was added to a final concentration of 10% (10 kPa) in the headspace. Gas was sampled after 24, 36 and 72 h using syringe and directly analysed for N2O concentration by chromatography with ECD. DEA were calculated from the linear increasing of N2O production against the

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