The static closed-chamber method was used for collecting gas samples from wheat sowing to harvest.
Gas samples were taken once at an interval of 7 d in general, each day in the 15 d following fertilization and each day in the 3–5 d following precipitation.
Gas collection was performed in the morning between 9:00 a.m. and 11:00 a.m. and samples of 30 mL chamber air were collected at 0, 10 and 20 min after closure.
In the meantime, air temperature in the chamber was measured