Irrigation

Efficient irrigation management is essential for quality crop production. Irrigation is an alternative to dryland farming that allows farmers to control the amount of water supplied to crops much more precisely than rainfall. Crops that are not drought-resistant require irrigation to thrive. Different methods of irrigation include drip irrigation and sprinkler systems, as well as basin, furrow, and border irrigation.

Drip Irrigation

Drip or trickle irrigation uses a network of thin plastic pipes that drip water into the soil through outlets called emitters. This method dispenses water at very low rates and concentrates the dripping over the area where the roots of the plants grow, reducing surface runoff. Drip irrigation is suitable for row, tree, and vine crops. Drip systems can be expensive to install, so are most often used for high-value crops. Drip systems can also be automated to apply water every day if needed, for soil with high moisture content. Because drip lines are so thin in diameter and run the risk of being blocked, highly-filtered water is required for drip systems.

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Center Pivot / Sprinkler

Sprinkler irrigation involves pumping water through a series of mainline and lateral pipes that lead to sprinklers that spray water onto crops. Sprinkler irrigation is best suited for durable crops in sandy soil that can withstand high rates of water infiltration to avoid surface ponding and runoff. Sprinklers can be installed on the ground, or can be attached to machinery that moves over the crop area and distributes water, as in a center pivot irrigation system. Center pivots involve a pivot point that a long arm of trusses and sprinklers rotates around, in order to irrigate a circular area.

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Irrigation Management

Irrigation management is impacted by many variables, including soil composition, site slope, and depth of groundwater. Some variables can be controlled, like irrigation frequency, water use efficiency, and application amount. Following best practices for irrigation management will help ensure that water is used efficiently and distributed evenly across crops, as well as kept contaminant-free. Best practices include modifying equipment as necessary, scheduling irrigation, leveling land, proper tillage, and reducing runoff and leaching. Another important consideration for irrigation management is proper chemigation, as irrigation practices can cause chemicals to move away from the target application site.

Irrigation Efficiency

Irrigation efficiency means reducing water wasted through transport leaks, deep percolation or leaching, reservoir evaporation, surface ponding, and field runoff. Irrigation water should be delivered directly to the plant’s root zone to reduce waste. Scheme irrigation efficiency is expressed as a percentage and measures the proportion of pumped water that is being effectively distributed to crops. This measurement can also be divided into conveyance efficiency and field application efficiency to narrow down the source of irrigation issues. Conveyance efficiency measures effective transportation of water through irrigation canals, and field application efficiency measures water effective water supply in the field.

Irrigation Regulations

Irrigation regulations are in place all over the United States and Canada to prevent overuse of freshwater, a renewable but diminishing natural resource. Specific regulations are set by local governments, but generally restrict water use to certain times of day or days of the week. Restrictions ensure that municipalities can meet the demand for treated water, especially during dryer summer months when water is scarcer.