Quick and Easy Installation

Irrigation Journal, March 1995

Most farmers who use surge irrigation retrofit it to their existing pipe system. Surge works equally well with hard- or soft-gated pipe. By customizing the placement of the surge valve in the field, farmers can compensate for side slope and point rows in fields where acreage left and right is unequal.

Although surge is extremely versatile and can be configured in numerous ways, two common setups account for the majority of surge installations.

In the first type of field, where risers and hydrants are spaced over underground line in a rectangular field, place the valve at the hydrant and tee off into an equal number of gates left and right.

In the second type of installation, where a level field has corner wells or hydrants, simply double pipe to the center of the head of the field and tee off with the valve left and right.

Once the surge system is installed, adding fertigation is quick and easy.

Fertigating through surge gives the farmer the option of applying his fertilizer at any time during the season. Where ground rigs are limited by access to the field, surge fertigation frees the producer to put on fertilizer when the crop needs it and in any number of applications.

Research in surge fertigation by the Colorado State University Cooperative Extension has shown that nitrogen is best added to late soak cycles. If the calculated flow rate of the nitrogen fertilizer is too great for the capacity of the pumping application system, the fertilizer can be split between two or more soak cycles, as long as the last soak cycle is used to flush out the system.

Phosphorus does not move readily in the soil and must be added during each soak cycle to maximize penetration into the soil profile. The final soak cycle should be used to flush out the system.

To optimize the surge fertigation, the producer must know how many pounds of fertilizer are needed per acre, how many gallons of material are needed, how much acreage is under the surge valve, how long (in minutes) is the soak cycle and the chemical application rate.

With this information in hand, the grower also can fertigate with surge by allowing it to flow by gravity through some form of a constant head-metering valve at a convenient point before the surge valve -- such as into an alfalfa valve or an open channel.