Precision Irrigators Network
Helping growers conserve water and schedule irrigations
By Danielle Supercinski
Growers are becoming more involved with on-farm irrigation research to conserve water through the Precision Irrigators Network (PIN) project, funded by the Texas Water Development Board, which came from a natural progression of the Rio Grande Basin Initiative (RGBI).
“RGBI provided the lab to develop the knowledge we have of crop-water use,” said Dr. Giovanni Piccinni, assistant professor of crop physiology with the Texas Agricultural Experiment Station. “Lysimeters at the Uvalde Agricultural Research and Extension Center allow us to provide growers in the region with precise data of crop-water use. The Uvalde Center currently has five lysimeters installed, with two more to come sponsored by the Wintergarden Groundwater Conservation District.”
In addition, RGBI provides precise research data that must be done on the research station farm so if losses occur they can be corrected. PIN then takes this research to the growers to calibrate it further for the Edwards region. Researchers want growers to implement an irrigation schedule based on precise meteorological data from nearby weather stations, providing estimates of evapotranspiration (ET) and crop coefficients developed using lysimeters.
“PIN provides a support system for irrigation management. Irrigation needs to be calibrated to different soils, cropping systems and the environment,” Piccinni said. “We’re trying to do this with the collaboration of the growers so they can see how it works on each farm.”
When a grower begins participating in PIN, researchers visit with the growers, go on-farm and look at the field, and try to collect data off the field – crop rotation, irrigation schedules, type of irrigation, planting date, plant growth, soil type, etc. Watermark sensors are installed to monitor soil moisture. This data is inputted into a computer model and researchers explain the information they have found to the growers.
“These irrigation scheduling data are then compared with the grower’s experience and knowledge of the field,” Piccinni said. “Then we compare his irrigation schedule with what the potential ET calculator is telling us, what the soil moisture sensor is telling us and what the grower experience is telling us. This way, everyone is participating in the research process.”
Once the growers buy into this process and the new irrigation strategies, it is more likely their neighbor can see what’s going on and buy into it as well. Piccinni is trying to get away from grower’s skepticism of these irrigation practices working at the research center plots, but not in the field.
“PIN has allowed us to get away from small replicated research plots and do large scale research with different treatments imposed by the landscape variability that exists throughout the Edwards region,” he said.
The ultimate PIN goal is for growers to gain more knowledge on how to schedule irrigations and how to manage limited irrigation.
“We know how to manage full irrigation, unfortunately, given water restrictions in this region, full irrigation is often not an option,” Piccinni said.
The PIN project currently consists of 15 growers throughout Atascosa, Bexar, Frio, Medina, Uvalde and Zavala counties. Researchers work with the PIN growers to help schedule limited irrigation by using decision support systems such as the potential ET networks and CroPMan computer models.
Growers, county Extension agents and researchers all collaborate and work together on this project to implement efficient irrigation management. Extension agents identify growers to participate in PIN, and they hold meetings to explain how PIN works to the growers.
Kenneth White, ag and natural resources county Extension agent in Uvalde County, is one of these county agents who began implementing PIN in the fall of 2004 by taking ET information out to a few grower’s fields.
“The first cooperator I used the data logger and sensors with kept track of fuel costs and irrigations,” White said. “He reported they were able to save more than 4 inches of irrigations, or 50 acre-feet of water, and fuel costs of $20 per acre. They used this information on their bermudagrass pastures and winter pastures.”
He currently works with 11 growers on corn, cotton, bermadagrass and cool season forages. Watermark sensors and data loggers are established in all fields, and result demonstrations on drip irrigated onions, spinach, cantaloupes and warm season grasses are established.
“As a result of implementing the PIN and weather stations, growers and consultants will be able to use local ET Web sites, newspapers and radios to assist with their irrigation scheduling,” White said.
Bill Howell, producer at the Chaparrosa Ranch west of La Pryor, said: “Utilizing the information from the weather station takes 85 to 90 percent of the guess work out of how much water to apply in their forage operation. I can use that information along with information from the watermark sensors to determine when I need to irrigate our forages.”
Austin Clary, a cotton producer in Sabinal, called White asking if he was still planning on establishing result demonstrations on using soil moisture sensors and data loggers. Clary said this was the best and most informative information he has ever used to assist him with his irrigation scheduling.
“We want to give as much water as the crop needs and not a drop more because we want to make every drop count,” Piccinni said.
