What is a flood: from direct sowing to flood protection to avoid damage

What is a flood?

The meaning of the word “flood” itself is “praise of water”, but in agriculture it is called “flood” which is the custom of pouring water into the field. On the other hand, unnecessary accumulation of water in arable land due to inadequate drainage is also referred to as “inundation”, and damage to agricultural produce is referred to as “damage caused by flooding”. Flooding is a necessary and sometimes controlled problem in agriculture.

The submerged field is divided into soil and water layer, soil layer is divided into “oxidation layer” and “reducing layer”. In the reducing layer, organic nitrogen in the soil becomes ammonia due to the action of microorganisms and is absorbed by the rice roots, playing an important role in the growth of rice plants. In addition, floods bring many benefits to paddy fields, such as easier control of weeds.

The difference between directly sowing a wet field and sowing a dry field directly

Both direct sowing in flooded fields and straight sowing in dry fields are farming methods in which seeds are sown directly in paddy fields. The big difference is that the cultivation method to fill the field with water before sowing seeds is “straight sowing”, while the method of sowing in fields without water is “sowing dry fields”.

Submerged direct sowing has the advantage of being unaffected by the weather when sowing and less water leakage, but also the disadvantage is that sowing takes time due to difficulty in putting large machines into the field. .. On the other hand, sowing straight on a shallow field has the advantage of being able to do it for a while using a large machine, but it also has the disadvantage that it is difficult to sow the seedlings because weeds grow a lot and the soil tends to be too dry or too wet. ..

Inundation and ecosystem conservation

Floods also play a very important role in protecting natural ecosystems. Flooded rice fields are the feeding and breeding grounds of various creatures such as birds such as sagi, fish such as medaka and dojo, amphibians like frogs and insects like dragonflies, creating an ecosystem. diverse. I will. In addition to conserving the ecosystem, it will also be attractive for the product of safe rice grown in rice fields where many organisms live.

Storing water in the field “without watering” after harvest is called “freezing”. Because of winter floods when many birds fly to Japan, the rice fields become resting and feeding places for the birds. However, there is a need to ensure water resources and it does not appear that all fields can be inundated in winter, as this cannot be done for rice fields planted in winter as in two seasons.

Flood control business is carried out in many different places

A flood control project is a project that aims to prevent flood damage in areas where drainage conditions are impaired by factors such as river rehabilitation, urbanization, and land subsidence. New construction and rehabilitation of drainage machines and drainage canals are being carried out mainly to prevent floods from damaging agricultural land. This project is implemented by each province and city and the status of operation can be confirmed on the website of the local government.

By understanding flooding, you will gain a deeper understanding of agriculture, rice cultivation and even ecosystem conservation. If you want to get involved in agriculture or rice farming in the future, why not take a closer look at floods?

Supervisor: Shigeru Takahashi, Tohoku Center for Agricultural Research, Agricultural Research Organization http://www.naro.affrc.go.jp/