广东省珠江三角洲沙围田区是本省主要的商品粮基地。由于地处河口潮区,地势低平,河网纵横,常受洪潮顶托,排水不良,地下水位高,土层密实,土壤透水通气性差。采取排水措施,降低地下水位,可以增大土壤的垂直渗漏量,改善土壤通气状况,增强根系活力,促进水稻增产。一、田间工程措施。目前主要方式还是明沟排水,近年发展了暗管与鼠道。末级明排水 Sha-Tian District, Pearl River Delta, Guangdong Province is the province’s main commodity grain base. Because it is located in the estuary tidal zone, low flatness, vertical and horizontal river network, often by the flood top support, poor drainage, groundwater level is high, dense soil, the soil permeability is poor. Drainage measures to reduce the water table can increase vertical soil leakage, improve soil aeration, enhance root activity and promote rice yield. First, field engineering measures. At present the main way is ditch ditch drainage, in recent years the development of the underground pipe and rat. The last stage of drainage