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.
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 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 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.