HEREFORD Drip-irrigation systems are perhaps the most water-efficient way to irrigate vegetable crops, but producers need to plan carefully and do some homework on available resources before they install a drip system, said a Texas Agricultural Extension Service irrigation specialist at the recent West Texas Vegetable Conference here.
“You have to do a lot of planning beforehand in order to get a good system that meets your needs,” said Dr. Dana Porter, Extension irrigation specialist based in Lubbock. “And you have to ask yourself some hard questions.”
“You have to ask…How much water do I have? Is my well and water consistent? Is my well and water source reliable? What is the quality of my water?”
Drip irrigation is more water-efficient and energy-efficient than other systems and can help producers reduce some input costs if the system is equipped for chemigation (applying fertilizer and ag chemicals in the water).
“Drip-irrigated crops often yield more than furrow- or center pivot-irrigated crops, and there is less long-term labor required with a drip-irrigation system,” Porter said. “But there also are a few drawbacks.
“Producers with drip systems cannot use deep tillage to combat certain crop pests, and they often have fewer crop rotation options. Seed germination is another concern, because the water is applied below ground rather than at the soil surface. And drip systems can require more intensive management than furrow or center-pivot irrigation.”
Producers who decide to switch to drip irrigation should consult with a drip-irrigation engineer or consultant who can help them design a system suited to their needs, fields and crops, the irrigation specialist said.
“Most drip systems rely on a buried tape to place irrigation water near the plant roots. These systems must be designed well and properly equipped,” she said. “After you come up with a design that factors in field topography, well limitations, crop options, tape spacings and crop water needs, you should focus on learning your system and its key components.
“A good drip system will include effective filters. These help protect components in the system, and help minimize detrimental effects of contaminants such as sand, sediment, algae, bacteria and calcium carbonate. Filters also help maximize the life expectancy of a drip-irrigation system.”
Knowing how irrigation water moves in the soil also helps producers pick the right drip system and get the most from a system after it is installed, the irrigation specialist said.
“When you hire a consultant, engineer or firm to design and install a system, you need to ask several questions up front. Inquire about the system’s life expectancy how many years use can you expect to get from it with proper operation and maintenance?” Porter said. “Will they provide you with operating guidelines and some initial operations training? Does the system and components come with a warranty? And, what are my initial installation costs, long-term operating costs and annual maintenance costs?”
Producers should also take into account the ‘learning curve’ period after they choose and install a drip-irrigation system, she said.
“Running a drip system profitably and efficiently is quite a bit different than furrow or center-pivot irrigation,” Porter said. “In most cases, producers find that it takes one to three years of in-season experience to learn their system and the irrigation management strategies it offers.”
Porter was one of 11 featured speakers at the 1999 West Texas Vegetable Conference. This year’s day-long educational event attracted more than 150 producers and vegetable industry representatives from Texas and adjoining states.