Flood and drought crop rotation paddy field soil gas in-situ acquiring system and method

The invention relates to a rice field-upland field rotation rice soil gas in-situ acquisition system and an acquisition method thereof, which belongs to the field of the gas acquisition technology and is specially used for the in-situ acquisition of the soil gas in the rice soil section plane under the condition of the rice field-upland field rotation. The invention comprises that: PVC pipes withthe 40 mm inside diameter are chosen; total eight pores are uniformly distributed on the exchange interface of the pipe wall at the bottom of every gas cavity; all gas cavities are separated with PVCsheets which are perforated and allow a nylon tube gathering gas to pass through. A nylon slim tube passes through the upper part of the PVC sheets and is connected to a triple valve with a silicone tube. The acquisition method comprises detection of air tightness, installation, pre-equilibration and the system keeps airtight state; when in observation, a syringe directly gathers the needed voluminal gas. The invention can be used for gathering soil gas in the inundation state or in the drainage state, can gather in-situ gas with different section plane depth on the same locus, has easy operation and easily available materials, can be wildly applied to the rice field and wetland soil gas acquisition, and overcomes various kinds of defects in the prior art.