The Role of Drip Irrigation in Sustainable Agriculture

As water scarcity becomes an increasing threat across the United States, farms on smaller and larger scales are experiencing setbacks in food production. California, which is in the middle of a record breaking four-year drought, is still toying with different water conservation methods in their agricultural sector. Because California is a main producer in the fruit, vegetable, and tree nut industry, the drought has the potential to affect these supplies, fluctuating the economy of food production in the state. As the agricultural sector of California uses 40% of the state’s water, how do farmers work with irrigation? One of the main suggestions on lowering water use is seen in drip irrigation.

drip irrigation

Cabbage is grown in a drip irrigated field in San Domingo, Cape Verde.

Drip irrigation is a sustainable farming method that uses pressured water flowing through pipes with emitter heads or small holes, which are placed directly at the base of a crop, as water drips out of the emitter head drop by drop over a period of time. Drip irrigation is seen as sustainable because it is measured in gallons per hour rather than gallons per minute, and reduces water evaporation and runoff. Drip irrigation is also known to be efficient because water is delivered directly to the topsoil above root systems over a longer period of time, so the roots intake water at a more uniform rate and are not susceptible to flooding or over-watering. Oregon State University has suggested an even more efficient method of drip irrigation, subsurface drip irrigation, where the pipes are buried underneath the soil to directly reach the roots of a crop and further reduce runoff and evaporation.

driptape

Example of a drip irrigation line emitting water in single droplets.

Compared to other means of irrigation across the United States, drip irrigation seems to conserve more water and produce more “crop per drop” than other methods, cutting water consumption on crops by as much as 50%. In the widely used spray or sprinkler irrigation seen commonly in the Midwest, agricultural lands are well watered but about 35% of this water is lost due to evaporation. In the Western U.S., because of federal subsidies and “use it or lose it” laws seen in Western water rights, farmers are encouraged to use flood irrigation, which loses a hefty amount of water to runoff.

Because of the controlled use of water and low cost of implementation associated with drip irrigation, it is a viable alternative for areas in the world that have a strict dry season, and areas that run on smaller economies. For example, in Haiti, there is a very defined wet and dry season. During the dry season when water is scarce, farmers would still be able to produce some amount of crops with minimal water usage. Because drip irrigation only requires a water pump, metal or plastic tubing, and a few adapters to connect the tubing to the pump, low-income communities could afford this method of irrigation even during the dry season, and could increase food security for their families and communities.

Although drip irrigation may seem like the end-all solution for water conservation in the agricultural sector, some have argued that is does not actually save water. In a 2008 study from the Proceedings of the National Academy of Sciences, it was found that sustainable irrigation techniques like drip irrigation may actually increase the amount of water consumed by crops. This is because when using drip irrigation over flood irrigation or sprinkler irrigation, a field of crops will use water more efficiently. Because of the efficient evapotranspiration of the crops, they will be at peak growing capacity, and will use just as much water as other means of irrigation. Although these plants may be consuming the same amount of water, because they are consuming it in a uniform rate which puts them at peak growing capacity, crop yields associated with drip irrigation are higher.

 

Image credits:                                                                      http://www.csmonitor.com/World/Making-a-difference/Change-Agent/2011/1020/Cheap-drip-irrigation-could-transform-small-farms http://en.deere.co.th/en_TH/products/equipment/irrigation_and_water_management/drip_and_micro_irrigation_emission_devices/drip_tapes/t_tape/t_tape.page

 

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4 Comments

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4 responses to “The Role of Drip Irrigation in Sustainable Agriculture

  1. amyquandt

    In your research did you read anything about what farmers thought of drip irrigation? Are they in favor of it, or against it?

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    • kennethprior

      Smaller scale farmers are in favor of it. Last summer I worked on a family owned farm that was very in favor of drip irrigation, all of our fields were set with drip lines and we didn’t rely on any other method. However, this was probably because of the small scale of the farm and farming operations. Larger scale farms that have high outputs, are exporting their crops to various places and using high-yield farming vehicles/techniques don’t utilize drip irrigation very much.

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  2. adampeterman

    From all the benefits I hear about drip agriculture, I am surprised that more farmers in the US aren’t using this method. Did you learn what percentage of Californian farmers are using drip irrigation? If it uses less water and increases yields, this seems like it would be an easy choice for farmers to make. It would be an interesting case study to examine other dry areas in the world that use drip irrigation and see how their water usage/agricultural production compares to that of California.

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    • kennethprior

      Well, as it was stated in the article, drip irrigation doesn’t EXACTLY use less water. Drip irrigation allows crops to use water more efficiently, which also allows the crops to evapotranspirate more efficiently. Because of this, they will be taking up about the same amount of water as seen with other methods of irrigation, but this efficient usage of water by the plants will increase yields. It is hard to say the percentage of California farmers utilizing drip irrigation, but I can tell you that it is definitely on a smaller scale. I do not believe that high output farms in California that are exporting their crops to various places utilize drip irrigation, but smaller plots of land that may be privately owned are known to use drip irrigation.

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