Irrigation is a common agricultural/horticultural practice that uses a number of methods to add water to the soil in times of insufficient rain. Choosing the appropriate method depends mostly upon crops, soils, and climate conditions.
Irrigation techniques can be grouped in two major categories: surface irrigation (furrows, borders, flooding), which use the soil as the distribution mean; and pressurized irrigation (sprinkler, drip). Pressurized systems can be subdivided into high pressure systems (sprinklers) and low-pressure systems (sprinkler and drip irrigation) which distribute the water using pipes.
Drip irrigation is widely used around the world. The reasons for the popularity of this irrigation method are: 1) Due to the fact that the water is applied directly to the crops, the water loss is minimal, and fertilizers can be applied simultaneously (fertigation). 2) Drip irrigation can be used for most crops, soils, topography, and climate. 3) It helps control weeds because the area of soil not occupied by the crop remains dry. The main disadvantage is its relatively higher installation costs.
A typical drip irrigation system usually includes: 1) a water source (well, river, etc.); 2) one or more filter systems; 3) a fertilizer tank; 4) distribution and application pipes; 5) emitters; and 6) a number of control devices such as timer, water and pressure regulations, backflow preventers and pressure relief valves. The system can be simple or complicated depending upon the size of the property and the terrain. If designed and installed properly, the operation and maintenance costs are low, and the crop yields are high.
It is important to emphasize that drip irrigation systems not only convey, distribute, and apply water to the soil specifically where the crop roots are growing; they also allow us to apply fertilizers simultaneously, at the same specific locations. In the meantime, the rest of the field remains dry, and with limited weed growth.
Alaska is a great state with abundant natural resources such as oil and gas, mining, timber, and wildlife. Tourism is also an important source of income for the state. Agriculture and horticulture, however, are not very strong due to the climate. So, the incorporation of irrigation practices to existing dryland production can help improve food security. Drip irrigation is an excellent option.
Dario Canelon is an associate professor of Extension who recently moved to Fairbanks from the University of Minnesota. Originally from Venezuela, Canelon has more than 20 years of teaching and research experience at the University of the Andes in Venezuela, specializing in soil and water engineering. He also has more than 15 years of applied research in Minnesota in agricultural water management and cropping systems modeling. You can reach him at 907-474-2423 or djcanelonsanchez@alaska.edu.
