Researchers at CSU Monterey Bay and NASA are testing a new way to help California farmers decide exactly how much water to use on their crops. It’s a tool that could eventually help growers anywhere save on a precious resource.
On Anthony Pereira's family farm in Los Banos, he grows cotton, alfalfa and tomatoes. And he is constantly deciding how much water is the right amount to use. “Water savings is always an issue. That’s why we’re going drip here now on this ranch. So we got to try to save what we can now for the years to come,” said Pereira. To help farmers like Pereira, NASA and CSUMB (KAZU’s parent institution) are developing an online tool that can estimate how much water a field might need.
Here’s how it works. Satellites orbiting earth take high resolution pictures. Pictures so detailed that you can zoom in to a quarter of an acre. CSU Monterey Bay Scientist Forrest Melton is the lead researcher on the project. “So the satellite data is allowing us to get a measurement of how the crop is developing. We’re actually measuring the fraction of the field that’s covered by green, growing vegetation,” said Melton. Those images are combined with data they’re collecting right now at a dozen California farms.
In Pereira’s fields researchers are planting sensors underneath and around the crops. The sensors measure wind temperature, radiant energy from the sun and how thirsty the soil may be on a given day. Researcher Chris Lund is carrying equipment that will collect all that data. “Once a minute it’ll take a measurement of all the sensors that are attached to this, the soil moisture sensors, the soil water potential sensors, and in this case the capillary lysimeter I talked about that measures how much water is going out the bottom of the system,” said Lund. Using this information with the satellite images that are updated about once a week, the researchers have come up with a formula that can estimate how much water a field might need. Farmers will soon be able to access estimates for their fields online and eventually they’ll be able to use their cell phones. That means Pereira will no longer have to rely on an old-school way of deciding how much water to use. “Before, everything was furrow irrigated or flood irrigated, and we’d just schedule depending on what the weather is. if it’s warm, we say, OK we’re going to try to irrigate every two weeks. If it’s cooler, then let’s try to stretch it out another week, 10 days or so to make the water stretch out a little more,” said Pereira.
The research team sees their water-saving tool as something that could be used by any farmer. At the Ames Research Center in Mountain View, NASA’s Rama Nemani is looking at a map of the world mounted on a wall. “If you look at the map like this, there are a lot of areas that are like California that are starved for water that still have to produce food, so we have to figure out how to use whatever limited water each place has to the best possible extent,” said Nemani. This online water saving tool could be available to farmers around the state as soon as next year, and eventually to farmers around the world.
This research project is one of several supported by a 10-year, $32-million NASA grant recently awarded to CSUMB.