All growers probably wish managing their irrigation systems were as easy as matching a deflector and nozzle to a crop. Wouldn’t it be wonderful if there were a sprinkler with the perfect flow rate and droplet size for your potato field?
The reality is that finding the right equipment and attaining irrigation efficiency—that is, without runoff or soil sealing and with minimal evaporation and wind losses—is much more complex than just determining how much water potatoes need.
An efficient, well-designed irrigation system takes several factors into consideration, including pressure, drop spacing, wind speed and soil intake rate. This last factor is particularly important for growers with tight, clay-based soils.
Tight soils are a challenge for growers who depend on irrigation. Unlike sandy soils that can absorb almost 1 inch of water per hour, clay soils have extremely low infiltration rates around 0.2 inches per hour. These dense soils are prone to runoff, soil sealing and salinity issues caused by poor drainage and water evaporation from the soil surface. Heavy soils retain too much moisture and tend to harden as they dry, which leads to poorly shaped tubers and tuber rot.
Irrigation efficiency can be a little difficult to maintain when watering these clay-based soils, but effective and sustainable irrigation is entirely possible with equipment specifically designed to match your soil’s intake rate.
Lowering Application Intensity
Distributing the weight of the water over a larger area reduces soil compaction. This is why sprinklers that can wet the largest area possible in an instantaneous, 360-degree pattern are an incredible asset for combating surface sealing and runoff. This type of coverage helps reduce the impact of the sprinkler’s application pattern on the soil.
Think about a stream-driven device like impact sprinklers. These sprinklers throw water very far, but they apply a flow instantly to a relatively small area. On tight soils, this type of application pattern will result in surface soil structure degradation and runoff.
Distributing the water gently over a larger area helps preserve the soil’s intake rate and promotes deeper movement of water into the soil. This improved infiltration allows for longer and sometimes less frequent irrigation, which reduces the potential for both surface evaporation and plant disease.
Reducing the number of irrigation applications also results in less wear and tear on a pivot’s motors and gearboxes, and energy savings.
Dividing a Flow from the Mainline
Increasing a pivot’s wetted area and lowering application intensity doesn’t have to be expensive or time-consuming. Senninger Irrigation has found that dividing a flow from a single outlet on a pivot and spreading it out over a larger area is actually very effective at lowering a sprinkler’s application intensity. It gives soil time to absorb water at a comfortable rate.
All growers need to accomplish this are goosenecks and low-pressure sprinklers. No boom systems are necessary, and there is no need to alter the pivot speed. Senninger’s double 125-degree goosenecks with truss rod hose holders let growers install two separate drops on opposite sides of the mainline.
A standard goosenecks’ sole purpose is to allow the installation of drops along the pivot. Double goosenecks expand on this technology and help lower sprinkler application intensity while maximizing the efficiency of a sprinkler package.
With double 125-degree goosenecks, the drops are positioned at angles so sprinklers do not sit side by side as they would with conventional 180-degree goosenecks. By positioning the sprinklers farther apart, their wetted patterns are distributed over a wider area with less overlap. This increases a pivot’s overall area of coverage while still using the same amount of water. This installation also helps convert wide-spacing machines to closer drop spacing, reducing or eliminating the need for welding additional outlets.
Closely matching the soil’s intake rate prevents soil sealing, pooling and runoff. So, not only can growers preserve their soil’s health, they can also save water by making the most out of every drop pumped.
Don’t Forget the Sprinklers
A good sprinkler makes the double gooseneck installation even more efficient. No matter which sprinkler growers select, Senninger’s recommendation has always been to find a sprinkler that distributes water instantaneously and uniformly over a large wetted area.
Senninger’s i-Wob with a standard black plate or a gray plate is frequently requested with the double gooseneck. Its wide and gentle application pattern reduces the kinetic impact of droplets on the soil surface and works hand in hand with the gooseneck to maintain good root aeration and minimize erosion.
A professionally designed sprinkler package will provide the right application rate to help preserve proper soil structure and meet the needs of your crop.