Abstract
A sandy field has the potential hazard of nitrate contamination because of its low fertilizer holding capacity. A suction controlled flux sampler (SCFS) consisting of an automated vacuum system and a sampling filter device has been developed for accurate measurement of water flux from the root zone. Knowing that water content in sandy field was highly sensitive to suction change, a buffer container was placed between the pump and a sampling bottle to apply moderate suction and avoid accidental over-sucking. A sampling device with a glass filter was placed in a dune sand column and infiltration experiments were conducted. A moderate suction was achieved and the resulting water-collecting efficiency was from 94 to 109 % under continuous rainfall. It showed that SCFS collected infiltrated water effectively without disturbing the infiltration streamline.
