Irrigation has been practiced by humans for thousands of years by taking water from available water sources such as ground water or rivers and then being transported to land that requires additional water. Water collection, transportation and addition are carried out in different ways, depending on the level of progress and mastery of the technology and culture of the local community. The technology applied in irrigation activities can be in the form of technology that is very simple and local in nature, to high technology that is completely “computerized” as has been done by several countries that have advanced in the field of irrigation technology.
Irrigation activities include taking water from its source, transporting water, distributing and giving or adding water to agricultural land that is in need, to support the growth and yield of agricultural crops. Moisture conditions suitable for growth differ for one type of soil and plants from another type of soil and plants. On a certain land with certain plants, sometimes there is no need for additional water to create moisture conditions that are suitable for the growth of the plant concerned, but instead it requires efforts or measures to reduce excessive moisture levels through the activity of drainage.
Draination is an effort to reduce excess water both at the soil surface and in the soil layer. Surface drainage is generally carried out to reduce excess water at the surface (inundation or flood). In the context of land productivity, drainage (reduction of moisture content) plays a very important role which is no less important than the role of irrigation (addition of moisture content). Draination also acts as a way to improve soil quality through the leaching process, especially for soils with high salinity or acidity. Irrigation and drainage are two interrelated activities, although the principles are different.