Figuring out how to get water to thirsty crops has been an issue for farmers since the ancient Egyptians captured Nile floodwaters to soak their fields in the spring and the Romans brought water to their fields with aqueducts. The core objective of irrigation – delivering just enough water for the crop’s maximum growth, no more, no less – has not changed since then. If only the ancient civilizations had known about micro irrigation.
Uniform, targeted water delivery is the hallmark benefit of micro irrigation systems. Water is delivered directly to the root zone of the plants in quantities sufficient for the plant’s needs while minimizing water loss through evaporation or run-off. Because water is applied uniformly and regularly, stress due to soil moisture fluctuation is reduced or eliminated, leading to increases in crop quality and yield.
Bob Weimer, a partner with Weimer Farms in Atwater, California, has never looked back since installing a micro irrigation system on his farm in the late 1970s. “I don’t even like to think about what we were using before,” Weimer says. “I can remember growing up when we would go out at night and you’d start across a 40-acre peach orchard where you would have valves running and you would take a shovel and you would go across the field and change furrows in the middle of the night two or three times. I don’t even like to think about those days anymore.”
Drip irrigation is not maintenance free. “You still have a maintenance issue – you just change the things you do,” says Weimer. “It takes a different level of labor, more training, more technical use of people, but [drip] is effective.”
However, a properly designed and automated system will save a great deal of time, and even more importantly, deliver the water exactly where you want it.
"The one thing with drip irrigation, whether it be in row crops with drip tape or whether it would be in the orchards, is that it provides a uniformity of irrigation that we didn't have with furrow irrigation or flood irrigation or even with sprinkler irrigation in many cases,” Weimer says. “You can also do variations with the drip system to reduce water in certain areas if you have heavier soils that are holding water.”
Weimer says being able to deliver water directly to the root zone conserves water and likes being able to target the amount of water very closely. The efficiency of a drip system can be up in the 90 percent range whereas the efficiency of flood or furrow irrigation might be at 50-60 percent, he says. Because the rate of water flow is less than with other systems, smaller water sources can be used for the same amount of acreage.
An additional benefit of a drip irrigation system is the ability to deliver fertilizer directly to the plant. There can be a cost savings, particularly with nitrogen fertilizers that are particularly subject to leaching, because less fertilizer is needed.
There are some harvest and labor advantages as well. “If you’re doing sprinkler or flood irrigation you have to shut your water off sooner than you would like to. We can keep our water going closer to the harvest period on the almonds before we shut it down,” Weimer says.
Drip irrigation, if properly designed, can operate well on even hilly land. Because smaller amounts of water are delivered at a slower rate than other types of irrigation systems, there is little or no run-off or puddling in low areas.
“Growers would not be going forward with drip irrigation and using this type of system if it wasn’t for the success in production,” Weimer says. “We’re not going to go back from where we are with our drip and micro-type irrigation systems. It’s here to say and it’s only going to improve.”
"Growers would not be going forward with drip irrigation and using this type of system if it wasn't for the success in production,"- Bob WeimerWeimer Farms in Atwater, California