Fertigation
“where scientific knowledge make a difference in the service”
What is Chemigation?
Chemigation is the application of pesticides or system maintenance compounds through an irrigation system. Pesticides include herbicides, insecticides, fungicides, rodenticides, fumigants, spray adjuvants, and plant growth regulators. Disinfectants, sanitizers, buffering agents, desiccants, defoliants, and sprout inhibitors are also included under the pesticide definition.
What is Fertigation?
Fertigation is the application of a commercial fertilizer, soil amendment, or reclaimed water from food processing and wastewater treatment facilities with irrigation water. A commercial fertilizer is a substance that contains one or more recognized plant nutrients used for its plant nutrient content and is claimed to have value in promoting plant growth. Also included are lime, gypsum, and mixed or specialty fertilizer.
Potential Risks
Chemigation and fertigation can be effective and safe methods of applying certain chemicals to plants or to soil. However, a chemigation or fertigation system cannot draw water from any water supply unless that source is protected from contamination. To protect the water source from contamination, the irrigation system must be equipped with appropriate backflow devices to prevent backpressure and backsiphoning.
The greatest risk of chemigation and fertigation is the potential for accidental backflow of a chemical into the irrigation water source. To prevent contamination, an irrigation system along with anti-pollution safety devices must be properly installed, operated, and maintained. Chemigation or fertigation should not be performed under the following conditions.
Injection of a pesticide or fertilizer into an irrigation system on the suction side of the irrigation pump.
Direct connection of an irrigation system to a public water system.
There are three primary ways that irrigation water sources can be polluted. They are: Chemical in the supply tank and in the irrigation pipeline backflows or is siphoned into the water source when the irrigation system shuts down.
The irrigation system shuts down but the chemigation/fertigation system continues to inject the chemical into the irrigation water supply. With the loss of system pressure or with the reduction in water flow as to adversely affect application rate, the system interlock must discontinue product injection.