In agriculture, rainwater is the cheapest water source for crops but, unfortunately, water isn’t always reliable. A sufficient water supply to crops is vital for growth and abundant produce. Water is vital in semi-arid areas as well as hot and wet areas where rainfall is scarce.
Irrigation is reliable for both large-scale and small-scale agriculture, including kitchen gardens. There are four main irrigation methods used, especially for large-scale commercialized agriculture. Let’s jump right to it.
Surface irrigation is a standard irrigation method that relies on gravity to distribute water to the fields. This type of irrigation is suitable for areas with regular to mild slopes. Soils with minimum to medium infiltration rate and fine texture also are suited for this type of irrigation.
Surface irrigation requires plenty of groundwater and a workforce, as it does not rely on advanced machinery or technology.
There are various methods used in surface irrigation to deliver water to the fields. They include:
Basin irrigation involves flooding flat fields with water. The farmer encloses the crops or the fields in bunds, which is a small dike, levee or dam. Bunds help to prevent water from flowing to the nearby fields. Basin irrigation is best suitable for paddy rice and sugarcane.
Border irrigation uses gates and siphons to get water to the fields. The siphons and gates are in strips created within the fields and have borders, hence the name border irrigation. This type of surface irrigation is suitable for large farms that use machines to cultivate crops.
Furrow irrigation – This type of irrigation involves the use of channels that are arranged in a parallel manner to allow water to flow in the fields by gravity. This type of surface irrigation is ideal for crops planted in rows.
Advantages of Surface Irrigation
- Makes excellent use of rainwater, making it a cheap irrigation method
- Does not require advanced technology or heavy machinery
- Allows for leaching of salts in soils with minimum filtration rate
Disadvantages of Surface Irrigation
- It’s difficult to drain excess water from basins
- The degree of slope is very technical with this irrigation method
In sprinkler irrigation, crops get water from sprinklers set in the field based on the agricultural scale. The farmer pumps water through pipes that distribute water to the sprinklers spread out throughout the field. Water sprinkles to the crops like raindrops from the spray heads.
Sprinkler irrigation is effective for both small and large-scale farming, and you can use sprinkler irrigation on any slope. However, the overhead water supply method is dangerous to some vegetables, such as lettuce. In sprinkler irrigation, some sprinklers with bigger spray heads release huge water droplets, which could damage tender veggies. This type of irrigation is suitable for most soil types, especially those with a high infiltration rate. However, with sprinkler irrigation, you should only use clean water to avoid blocking the sprinklers.
When it comes to sprinkler irrigation, the two main categories of sprinklers are spray sprinklers and rotor sprinklers. They differ in their mode of water distribution. Rotor sprinklers have a rotating part that allows for the watering of crops in a cyclic pattern. Spray sprinklers, on the other hand, have a shower nozzle that distributes water in one direction. The shower nozzles are of different patterns depending on the amount of water required and the size of the farm.
The rotor sprinklers with nozzles are the most popular sprinklers available. You need to consider drop sizes and application rates when you buy a rotor sprinkler. Consider important factors such as spacing between sprinklers, nozzle size, and water pressure determine water application rate in sprinkler irrigation before you buy sprinklers. You should avoid large nozzle sprinklers which release large water drops, because they damage both crops and the soil.
Advantages of Sprinkler Irrigation
- Does not require skilled personnel
- Sprinklers are easy to operate
- Convenient for any type of slope
- Allows for conservation of water
Disadvantages of Sprinkler Irrigation
- It is an expensive irrigation method
- Water distribution is affected by strong winds and high temperatures
- Temporary sprinklers require an adequate workforce to set up and remove from the fields
Drip irrigation uses pipes with an opening called drippers. These drippers emit water to the crops at a low rate due to their size. Drip irrigation waters only the soils immediate to the closely surrounding plant. Drip irrigation is suitable for crops in rows, because each plant receives adequate water, because the soils are moist most of the time. Since it involves using pipes to supply water to each plant, drip irrigation is perfect for any degree of slope.
A great feature of drip irrigation is that you can set the drippers to drip water at different rates. The water drip rate depends on soil type, plant type, and degree of slope. For example, clay soil requires a low flow rate, while sand soil requires a high flow rate. Keep in mind that emitters or drippers with tiny diameters are prone to blockage. It’s essential to ensure that the irrigation water is clean and free of any sediments.
Advantages of Drip Irrigation
- It is very convenient where there is a fertilizer application
- Saves a lot of water
- Dramatically reduces the chances of weeds growing around crops due to the direct supply of water
Disadvantages of Drip Irrigation
- It requires skilled personnel to manage in areas with water rationing
- It is expensive to set up
- Regular cleaning of pipes is required to avoid blockage of the drippers.
Subsurface irrigation involves using pipes fitted beneath the soil surface. These pipes supply water to the plant roots, which is a very effective irrigation method. There are various methods of using subsurface irrigation, depending on the water table level. The tillage method is standard with subsurface irrigation. The subsurface irrigation method fits windy and dry areas since it limits the amount of water lost through evaporation. Like drip and sprinkler irrigation, the water used should be clean to avoid the blockage of the pipes.
Subsurface irrigation is fit for high-value crops such as strawberries and vegetables. It is also applicable in any degree of slope.
Advantages of Subsurface Irrigation
- Conserves water as it prevents water loss by evaporation
- It is not labor-intensive
- Allows for uniform crop growth and high yield
Disadvantages of Subsurface Irrigation
- Expensive to set up
- Drippers are prone to blockage
- Machines such as tractors can damage irrigation
Before picking any of the above irrigation methods, it’s crucial to put several factors into consideration. These factors include the degree of slope, type of crop, capital, and, machinery. If you need help planning an irrigation method for your property, we can help. Contact Cortada Landscape today.