Precision use of chemicals: chemigation

Description:	Chemigation is a technique developed over the last three decades that consists of incorporating any chemical (e.g., fungicide, insecticide, herbicide, fertilizer, soil and water amendments) into the irrigation water. Chemigation allows for a more precise application of agro-chemicals, thus reducing energy use (fewer chemicals, less tractor movements) and increasing yields (Burt, 2003). A chemigation system typically includes an irrigation pumping station, a chemical injection pump, a reservoir for the chemical, metering and monitoring devices, a backflow prevention system and safety equipment. Progress in equipment technology leads to increased precision and effectiveness. The latest chemigation systems are designed to work with different chemicals simultaneously. The chemical’s distribution uniformity is related to irrigation uniformity, which is dependent on a number of factors (i.e., wind, pressure differences in the emitting lines, clogging of emitters, unlevelled soils and soil infiltration rate).
References:	Burt, C.M. (2003). Chemigation and Fertigation Basics for California. http://www.itrc.org/reports/pdf/chemigationbasics.pdf
Additional sources	Borgia, C., Evers, J., Kool, M., & van Steenbergen, F. (2014). Co-Optimizing Solutions: Water and Energy for food, feed and fiber. World Business Council for Sustainable Development.