Strongly swamped rice field

...Rice paddies whose soil cannot dry out even during non-irrigation periods. This is a term for dry paddies that can be dried and used to grow field crops. There are various soil moisture conditions, from heavily wet paddies that remain flooded even during non-irrigation periods to semi-wet paddies that can be drained to a slightly moist state. Most wet paddies are located in low, marshy areas with poor drainage and high groundwater levels, but paddies that must store precipitation and use it as irrigation water, such as rain-fed paddies, are wet paddies even if they are located at high altitudes.

*Some of the terminology used to describe "highly wet rice fields" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…非灌漑期間にも土壌を乾かすことのできない水田。乾かして畑作物の栽培に利用できる乾田に対する用語で，非灌漑期間も湛水（たんすい）状態にとどまる強湿田から，やや湿った状態にまで排水できる半湿田まで，土壌水分の状態にはさまざまなものがある。湿田の多くは，排水不良で地下水位の高い低湿地に分布するが，天水田のように，降水などを貯留して用水として利用しなければならない水田は，高所にあっても湿田となる。…

※「強湿田」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報