Irrigation

People use water to help plants grow.

This is called irrigation. It helps crops grow in dry lands. It can also keep plants safe from frost.

There are many ways to do this. Some people let water flow over the soil.

Other ways use pipes. Some tools spray water high in the air.

Some pipes give tiny drops to each plant. This helps save water. Irrigation helps us grow much more food.

Irrigation is the way people give water to land.

This helps crops, lawns, and plants grow. People have used irrigation for over 5,000 years. It is very important for making food. In fact, 20% of farm land makes 40% of our food.

There are many ways to move water. Surface irrigation is the oldest way. Water flows over the soil using gravity.

Some people use sprinkler irrigation. This uses pipes to spray water into the air. Other people use drip irrigation. This sends tiny drops of water to the roots. It uses less water than sprinklers.

Water can come from many places. It can come from rivers or lakes. It can also come from wells deep in the ground. Some people even collect water from fog. Irrigation helps us grow food in dry places. However, we must use water carefully. Too much water can hurt the soil. We must share water with cities and animals too.

Irrigation is the practice of giving controlled amounts of water to land.

This helps farmers grow crops like wheat, rice, and cotton. It also helps maintain lawns and landscape plants. People use it to help plants grow in dry areas. It can also be used when there is not enough rain. Irrigation even helps protect crops from frost. It can also keep weeds away in grain fields.

There are several ways to supply water to plants. Surface irrigation is the oldest method.

This is also called gravity irrigation because water follows the slope of the land. Sprinkler irrigation uses pipes and high-pressure devices to spray water overhead.

Micro-irrigation uses a piped network to give small amounts of water to each plant. Drip irrigation is a special type that delivers water directly to the roots.

Some people even use subirrigation to raise the water table under the soil.

People have used irrigation for over 5,000 years.

The scale of irrigation has grown very quickly over time. In the year 1800, only 8 million hectares were irrigated. By 1950, that number grew to 94 million hectares. By 1990, it reached 235 million hectares.

Today, irrigation is a huge part of how we feed the world. In fact, 20% of farming land produces 40% of our food.

Water for irrigation comes from many different places. It can come from surface water like rivers, lakes, or reservoirs.

It can also come from groundwater found in wells or springs. Some people use non-conventional sources too. These include treated wastewater or even desalinated water. In some places, people collect water from fog using sheets.

This helps people grow food in very dry landscapes.

Irrigation is used all over the world in different amounts. Most irrigated land is found in Asia, which holds about 70% of the total.

India and China have the largest irrigated areas. The United States and Europe also use a lot of irrigation. We must use water carefully to avoid problems. Using too much water can lead to water pollution. It can also cause salt to build up in the soil. We must balance the needs of farms with the needs of cities.

Irrigation is the practice of applying controlled amounts of water to land.

This process helps grow crops, maintain landscapes, and revegetate disturbed soils. It is especially vital in dry areas or during times of below-average rainfall. Beyond simple plant growth, irrigation serves many specialized roles. It can protect crops from frost and suppress weed growth in grain fields. It also prevents soil consolidation and can be used to cool livestock. In some settings, it helps reduce dust, dispose of sewage, or support mining operations.

There are several distinct methods used to supply water to plants. Surface irrigation, also known as gravity irrigation, is the oldest form.

In this method, water moves across agricultural lands by following the slope of the land. It can include furrow, border strip, or basin irrigation. Sprinkler irrigation uses pipes to move water to central locations. High-pressure devices then distribute the water overhead.

Micro-irrigation is a more precise system using a piped network under low pressure. Drip irrigation is a specific type of micro-irrigation that delivers water directly to the root zone.

Finally, subirrigation involves artificially raising the water table to moisten soil below the root zone.

Water for these systems comes from many different sources. Most water is drawn from surface water, such as rivers, lakes, or reservoirs.

It can also come from groundwater extracted from springs or wells. Some regions use non-conventional sources like treated wastewater or desalinated water. In certain climates, people use fog collection with canvas or foil sheets.

Even air conditioning condensate or seawater can be used in innovative ways. For example, a farmer in Scotland uses wind power to pump seawater for salt marsh crops.

Irrigation has a long and expanding history. Humans have used these techniques for over 5,000 years.

The global scale of irrigation increased dramatically during the 20th century. In 1800, only 8 million hectares were irrigated worldwide. By 1950, this grew to 94 million hectares. By 1990, it reached 235 million hectares.

By 2021, the global land area equipped for irrigation reached 352 million hectares. This is more than twice the land area equipped for irrigation in the 1960s.

The significance of irrigation to the global food supply is massive. While irrigated land is a fraction of all farmland, it is highly productive. Specifically, the irrigation of 20% of farming land accounts for 40% of total food production.

Different crops have very different water needs during their growing periods. For example, sugarcane requires 1500–2500 mm of water. In contrast, onions only need about 350–550 mm. Understanding these specific requirements is essential for efficient management.

Irrigation is distributed unevenly across the globe. Asia contains the vast majority of irrigated land, accounting for 70% of the total.

India and China have the largest irrigated areas, with 76 million and 75 million hectares respectively. The United States follows with 27 million hectares. Other major areas include the Mississippi-Missouri river basin and the Nile river in Egypt and Sudan. These regions often use irrigation to increase the production of wheat, rice, or cotton to reach self-sufficiency.

However, irrigation also presents environmental challenges that must be managed. Over-irrigation can lead to poor distribution uniformity and wasted water. This can cause water pollution from leaked chemicals. It can also lead to the depletion of underground aquifers through overdrafting. Rising water tables from over-irrigation may cause irrigation salinity problems. To fix this, farmers often use subsurface land drainage to control the water table. Managing these hydrological changes is a key part of modern agriculture.