When I decided last summer to become a specialty melon grower, I embarked on an ambition that faces a huge challenge in Texas: Melons need tons of water to grow, and the state has been suffering a drought. For the last three years, lake levels have dropped and water restrictions have spread.
But I feel undaunted, because 10 years ago my father introduced me to drip irrigation, a method for watering crops that has proved effective in regions of the world much more arid than ours. Drip irrigation is versatile. The components can be customized for hundreds of acres of crops or just a backyard patio of potted plants.
The first building block is polyethylene tubing. It's the primary channel for transporting water from an outdoor water spigot to a plant. The tubing is a half inch in diameter, and it comes in rolls 25 feet long and up. Compared to a more expensive garden hose, it's cheap: A 100-foot roll costs as little as $10.
Drip irrigation is versatile. The components can be customized for hundreds of acres of crops or just a backyard patio of potted plants.
To this tubing, you can add other components such as emitters that drip drops of water at a set rate, mist sprayers, and soaker hoses that dribble water out along the whole length of the hose.
Large-scale system
For my crop of Israeli melons, my father and I built an elaborate system with lots of flexibility. To give some perspective on the size: I planted about 100 basins, not mounds, with four or five seeds in each basin. Each basin is about the size of a small sink.
I formed them six feet apart from each other in long rows. Each row of 20 basins spans about 120 feet in the field. Each row is spaced 10 feet apart – wide enough for our tractor to pass through until the vines sprawl out and fill in the space.
We unrolled tubing down the length of each row and placed it over the middle of the basins. Using a hole punch tool, we punched two holes a few inches apart in the tubing, near the center of each basin. Into each hole, we inserted a connector that allowed us to attach a smaller quarter-inch polyethylene tubing, about six inches long. We capped each smaller tube with an adjustable drip emitter.
Now each basin is watered by two emitters that can be directed anywhere within the basin that the seeds sprout.
After placing the emitters along the main tubing, we capped off one end by crimping it with a hose clamp. On the other end, closest to our water tanks, we added a fitting that allows us to connect the tubing to a regular garden hose. Now we can pump water from our 15,000-gallon rain water reserves to the drip irrigation lines out in the melon field.
Each adjustable drip emitter is set to release about five gallons of water per hour, so we only need to turn on the pump at the water tanks for a few minutes each day. Compare that to watering the sprouts manually, which used to take over an hour and a half. The system not only saves water, it saves time.
Smaller scale
I use simpler setups for other crops planted in smaller areas. For two rows of okra and two rows of corn, I use a quarter-inch soaker hose to dribble water out along the whole row, next to the base of each plant.
For tomatoes, I place half-inch tubing along the row and punch drip emitters directly into it. Tomatoes are more established with a larger root zone when they're transplanted. Anywhere that water drips near their base is sufficient, so they don't need the elaborate tubing used for the melons.
Climate change
Back in the early '80s, when I was a junior high student growing a few dozen hills of cantaloupes each summer, I could water the seeds for as long as it took to sprout them and help them establish roots, and natural rainfall would take over from there. A perfectly timed thunderstorm always seemed to roll in a couple of times in June; at least one shower would take care of July.
Soon after the last rainfall, the melons were ready for harvest. If I needed to water the vines by hand, it was only occasional.
Now, 30 years later, rainfall is scant. Several summers have come and gone in the last few years with no significant rainfall at all. Having lived in the same house for four decades and having always had an interest in the weather, I can say that I have observed a change in the climate. Climate change is real.
Because summers are now hotter and drier, irrigating crops is no longer optional. Fortunately, drip irrigation is an effective, low-cost method for keeping farming a viable career in our parched state.
Water drips from an adjustable drip emitter keeping a potted petunia hydrated.
