Concept:Irrigation is the artificial application of water to farmland in order to support crop growth.
Explanation:Farmers practise irrigation by directing water to their fields through artificial means such as channels, sprinklers, or drip systems.
This method is especially useful when rainfall is too little or when the dry season sets in.
Irrigation helps to supply consistent moisture to the soil for seed germination and healthy plant development.
Among the options given, only irrigation specifically describes the artificial watering of farmland.
Application and supplying are too general, while manuring refers to adding organic or inorganic fertilisers to the soil.
Thus, the term that correctly fills the blank is irrigation.
Answer:D. Irrigation