Paddy crop is strongly influenced by water supply. Water should be kept standing in the field throughout the growth period. In water scarcity areas, saturated soil in a chemical reduced stage is desirable. The characteristics of flooded soil which are conducive to high yields are: (i) greater availability of nutrients such as phosphorus, iron and manganese, (ii) suppression of weed competition, (iii) elimination of moisture stress as a limiting factor, (iv) micro-climate favourable to crop production.

 

Drainage of water from the field can be very important during the time of crop establishment, high rainfall events and during attacks by crop pests.