Written by Tara Sweeney
Sustainable Groundwater Management Act
Anyone in California can tell you—California is facing a water problem. The majority of that water is being consumed by agriculture—according to the USDA, it accounts for 80 percent of the United States’ water consumption. In many Western States, it can account for over 90 percent. In 2012, California was the state with the second largest agricultural acreage at 7.9 million—at about 14 percent of the Nation’s total.
In the wake of increasing drought risk in “The Sunshine State” the Sustainable Groundwater Management Act (SGMA) was signed into California law in September 2014, the act requires local governments and water agencies to reduce water use, reaching a balance between pumping and recharging groundwater basins by 2040 for critically overdrafted basins, then 2042 for the remaining high and medium priority basins.
Groundwater Sustainability Agencies (GSAs)
Localized GSAs work within city governments to meet their specific land-use and water-management requirements; SGMA groundwater management is a platform that can help local growers, GSAs, and local governments track and monitor water use in relation to current basin levels. UC Davis defines the SGMA online portal, under the California Department of Water Resources, as a platform for local GSAs to create groundwater sustainability plans to show how they plan to balance groundwater pumping with groundwater replenishment within 20 years, without undesirable results such as subsidence—the sinking of an area of land due to the movement of underground materials. These local agencies will create local solutions that will vary from basin to basin.
How are growers meant to track their ET (evaporation to transpiration) ratio efficiently, to ensure that they are compliant with GSAs by adopting Groundwater Sustainability Plans? Each GSA has specialized requirements to react to their specific local legislation as well as their local water needs. As such, growers need to start looking into innovations in irrigation. Innovations for both assistance in monitoring water-use for ease of reporting to their GSA’s, and to streamline the efficiency of their growing operations.
Fresno State AgTechDay Showcase
That’s where Fresno State’s AgTechDay comes into play; on November 15, 2019 The Center for Irrigation Technology (CIT) hosted the event at Fresno State’s Water, Energy, and Technology (WET) center that acts as a hub of innovation incubating companies that can create products that will make tracking water usage—and meeting SGMA regulations more manageable.
Bill Green, Center for Irrigation Technology’s Education Manager was quoted as saying,
The event provided monitoring and controlling device option overviews for the industry with examples. An Agricultural Consultant, Researcher, and Sales Representative explained how their methods and devices worked at the water source at the plant source, and devices that worked in-between. Below is a brief explanation of their offerings and how they can benefit growing operations at each stage in the water management process.
At the Water Source
Some of the technologies proposed would help growers and GSAs monitor water use at the source. Examples of which are specialized fertigation—injection of fertilizer or nutrients into the irrigation system—methods, collecting data via digital platforms to upload to the SGMA online platform, and monitoring power and water data wirelessly at the point of utility power meters.
Among the orchards in Fresno State’s Agricultural Laboratory, Agricultural Consultant William D. Jones proposed a strategy—based on his research with blueberries and similar crops—for more efficient fertigation. Firstly, that the measurements of concentration of fertilizer in the water source (parts per million) and amount of fertilizer applied to the field (pounds per acre) of fertilizer nutrient elements. Secondly, placement of the elements directly in the root zone. Thirdly, more suitable fertigation equipment were key to improving crop yield and quality for growers while protecting the groundwater resource from the leaching of those chemicals.
Most growers base their fertigation measurements on the amount (lbs/acre) of fertilizer; Jones suggested that this can cause an inconsistency and overuse of fertilizers. As such, Jones suggested fertigation be measured by concentration (ppm) in the water provided at the root source to both provide consistent fertilizer application, as well as preventing excess fertilizer nutrients being carried into the groundwater resource. Jones created a chart outlining the amount of fluid fertilizer and pounds of nutrient element per one acre inch of water for each element. Useful dry fertilizer products he noted were urea, ammonium sulfate, ammonium phosphate, MAP, DAP, calcium nitrate, ammonium nitrate (scarce), and potassium nitrate. Useful fluid fertilizer products he noted were CN 9, CAN 17, UAN 32, and 10-34-0 Polyphosphate.
Considerations that he suggested for the implementation of a more efficient fertigation system are whether the injection installation system were to be stationary or mobile; whether nutrient configuration be in single tanks—either single nutrient or multinutrient with chemical compatibility considerations— or multiple tanks for multiple elements; along with nutrient types and concentrations to be mindful of.
For more information you can contact William D. Jones, Certified Crop Advisor via email email@example.com or call his office at (559) 642-3650.
Alongside the canal in the outreaches of Fresno State’s Agricultural Laboratory, PowWow Energy presented on how their digital platform provides integration and reporting. PowWow uses the currently installed SmartMeters to monitor water use—saving on the cost of hardware in that respect—for reporting to GSAs, along with telemetry stations to track the groundwater table. Their system’s algorithms can help set a baseline of data, potentially identify problems, and track measurable results.
Morgan Halpenny presented the Pumpsight meter, which provides measurement of power and water data via a wireless receiver. providing measurement of power and water data via a wireless receiver. Pumpsight also uses telemetry—the process of recording and transmitting the readings of an instrument—and they are compatible with radio frequency systems that have a common published interface (LoRa, Zigbee, SigFox.)
Firstly, Pumpsight offers pump optimization with efficiency and cost analysis, measuring when and how much water is applied, and being able to respond to line pressure and water table changes. Secondly, the system offers failure prevention by identifying degrading equipment, monitoring well levels for rehab and maintenance needs, and system alerts for blowouts, power outages, or equipment failures. Pumpsight’s data logging feature’s higher frequency of sampling can provide better information resource for making water management decisions, measure the impact of conservation efforts and equipment upgrades, along with recording historical water consumption. Halpenny suggests that the increased frequency will allow users to respond more quickly to water needs, instead of the traditional measurement comparing the beginning of the season to the end of the season.
The previous technologies monitor water use at the source, further on we will discuss technologies that are attached to the plant and one that acts as a water control measure between the source and the plant.
Attached to the Plant
Researchers from the Electric Power Research Institute (EPRI) evaluated a series of devices that measure sap flow in individual plants, equipping vineyards to optimize irrigation — meeting water conservation goals and realizing energy and financial savings.
EPRI Engineer/Scientist Ryan Berg presented research led by EPRI’s Sudeshna Pabi and Marek Samotyj on “Plant Aware Irrigation” (PAI) developed by Fruition Sciences, supported by the California Energy Commission’s Electric Program Investment Charge Program, through Commission Agreement Manager, Karen Perrin. Researchers assessed PAI’s potential benefits by quantifying water and electricity savings, along with crop quantity and quality at harvest.
The technology uses sap flow sensors installed directly on vine stems. Vines are selected using aerial imagery, and ground-based laser mapping. Proprietary algorithms use sap flow data along with climate data to derive a daily Water Deficit Index (WDI) alerting staff to irrigate crops when an established threshold is reached.
Researchers installed PAI technology at three test vineyards in Northern California’s wine country, each producing a different type of grape (cabernet sauvignon, pinot noir, and chardonnay). They evaluated results relative to traditional irrigation practices. The vineyards were selected to provide insights into the water/energy nexus and its relevance to climatic and grape variations. In addition to water consumption, data included berry sugar accumulation profiles to assess fruit ripeness and yield measurements over 12 months.
They reported that the water stress imposed in PAI treatment blocks indicated an average of 61% water and energy savings across all locations, with no effect on fruit ripening or yields. In fact, researchers and vineyard owners noted a qualitative and quantitative improvement, as measured by earlier berry ripening leading to:
• higher berry color content and more flavors;
• more uniform berry sugar accumulation profile; and
• similar or higher individual berry weight.
The research suggests that monitoring vines directly can potentially help keep plants healthy and producing to meet requirements, while enabling environmental and fiscal sustainability.
For more information you can contact Ryan Berg at firstname.lastname@example.org or (650) 855-8627.
The last technology to discuss goes between the plant and water source to act as a way to control the irrigation process.
Joseph Gallegos of Drought Diet Products presented a new technology, previously only used on smaller-scale urban, organic farming growing operations—used on berries and similar root systems—where the irrigation system creates a miniature virtual water table for application of water and fertigation nutrients at the root level. The system consists of post-industrial ABS plastic for the piping that is installed at the depth of the root system to release the water directly where it is needed instead of surface treatments which may not penetrate the soil completely. His company is looking for large-scale orchard operations to install an enlarged version of this system alongside every other row of trees. The goal of this is to reduce the loss of water through evaporation, and only use what the trees need. In the winter time the same pipe is used to recharge the groundwater from winter storms or snow runoff—equal to the amount of water
that was taken out during the summer months. End goal is groundwater balancing each crop year. More research needs to be done, to measure how this technology can be translated from small-scale urban farms to large-scale industrial farming methods.
For more information you can contact Joseph Gallegos at email@example.com
or call his office at (562) 301-5598
These innovations mentioned were only those of the featured presenters, for more information on other innovations available through those that participated in the trade show at Fresno State’s AgTechDay, please contact Courtney Meinhold, (559) 278-2066, firstname.lastname@example.org); for more information about Fresno State’s Center for Irrigation Technology (CIT) contact Charles Hillyer, email@example.com; for more information about the Water, Energy, and Technology (WET) center call (559) 278-2066 or fax (559) 278-6033).