海塘田是筑塘(即堤)防潮,围垦海涂而成的。奉化县的海塘田,分布在县境东南沿,面海背山。塘田土层虽然深厚,地势虽较平坦,但因水利问题没有很好解决,易旱、易涝:抗旱能力仅15天左右;日雨量超过100毫米开始受涝,3天的降雨量超过300毫米,水稻受淹日数在4天以上。加之土壤性状不良,灌水后糊烂,断水后板结、返盐;冬季有的用田储水,不能种植绿肥,有的田绿肥生长极差;耕作粗放,一年只种一熟早中稻。因此,产量 Sea pond is built pond (that is, dike) moisture-resistant, reclamation from the sea. Fenghua Hai Tong Tian, ​​located in the southeast along the county, the sea back mountain. Although Tangtian soil is deep and the terrain is flat, it is not well solved due to water conservancy issues. It is prone to drought and flooding: its drought resistance capacity is only about 15 days. Rainfall over 100 mm begins to be affected by waterlogging, and rainfall over 3 days exceeds 300 mm , Paddy flooding days in more than 4 days. Coupled with the poor soil properties, irrigation after the paste rotten, water after the plate knot, return salt; some winter field storage of water, can not grow green manure, some field green manure poor growth; Therefore, production