High quality pecans require water from either rainfall or irrigation. Most places rely on a combination of the two. In the western US, irrigation is a must due to the lack of rainfall. In the eastern US, irrigation is supplemental due to the abundance of rainfall. Most growers fall somewhere in between. Mature pecan trees can require as much as 2000 gallons of water per week during the growing season.
Types of Systems
Flood irrigation
Orchards that are established on near level grades are suitable for flood irrigation. Pipes, canals, and ditches are all used to supply water to the orchard rows. The pecan tree do very well with this type of system as the entire orchard floor is covered. 2-6 inches of water are apply with each application of water. Most systems require a minimum of 750 gallons per minute (gpm) with a high volume, low pressure pump
Buried Drip
One of the newest types of irrigation on the market is buried drip. Developed in arid Israel, micro emitters installed on black poly pipe is buried beneath the soil surface across the orchard floor. Special plows install the tubing with most being buried about 12-18 inches deep. These tubes connect to lateral lines and main lines across the orchard. Pump requirements are low pressure and low volume as compared to flood irrigation. Filtration is the key to a successful drip system. This system can be installed after the pecans are in production, but some roots would be disturbed.
Sprinklers
Impact sprinklers are also used in pecan production. Pressure is required to operate these types of systems. PVC riser are the most common in which to install the “Rain birds”. These risers are connected to a network of lateral lines, valves, and main lines. During harvest these risers can become a problem with the machines as they harvest the crop. Also livestock and these system do not go together. Cattle think those sprinklers are like a water park!
Micro Sprinkler
Micro sprinkler use the same type of supply lines as the sprinklers except the risers. A thin tube, known as a spaghetti tubing is installed onto the lateral line. A sprayer stake is installed above the soil surface to hold the tube. Many different patterns of water can be applied with different nozzles. Diameter of the water thrown can also be adjusted as the tree grows.
These are the most common types of irrigation for pecan production. What ever your system, water is one of the most critical component of producing pecans.
