drain ditch in the field
interception drain ditch
agricultural drainage ditch
airlift oxidation ditch
alternating triple oxidation ditch
ameliorated triple oxidation ditch
Carrousel oxidation ditch
Carrousel氧化沟
卡罗塞尔氧化沟
卡普塞尔氧化沟
卡鲁塞尔氧化沟
carrousel oxidation ditch process