Posts Tagged: irrigation
California's $86 million date industry produces more than half of the nation's dates. Most of the fruit is grown in the arid Coachella Valley. Despite efforts by growers to conserve water, data was lacking on date palms' actual water use to refine the best irrigation management for the crop until a recent research project led by Ali Montazar, UC Cooperative Extension irrigation and water management advisor for Imperial and Riverside counties.
“California dates are grown in the hottest and most arid climate in North America and require substantial amounts of water in order to bring a successful crop to fruition,” Albert Keck, Coachella Valley date grower and chairman of the California Date Commission, wrote in a letter of support for this project. “In addition, there is scant modern research specifically and technically focused on growing dates in North America.”
Montazar said there is a lack of irrigation management information on date palms worldwide.
“The information developed in this study is expected to have a worldwide impact,” he said.
To determine the evapotranspiration rate and crop coefficients for California date palms, Montazar teamed up with scientists at UC Davis, California Department of Water Resources, USDA Agricultural Research Service, and USDA Salinity Laboratory.
The experiment was carried out in six date orchards in the Coachella and Imperial valleys. The sites represent various soil types and conditions, irrigation management practices, canopy characteristics, and the most common date cultivars in the region.
“The findings of the project indicate that there is considerable variability in date palm consumptive water use, both spatially and temporally,” Montazar said. In other words, the amount of water the trees use varies considerably depending on each site's growing conditions.
He estimated the water needs for date palms planted in different soil types in the low desert region.
“Growers will be able to use the science-based information and tools developed by this project to determine their date palm water needs and optimize the efficiency of water and fertilizer use in their groves,” Montazar said.
The peer-reviewed article “Determination of Actual Evapotranspiration and Crop Coefficients of California Date Palms Using the Residual of Energy Balance Approach” is published in the journal MDPI Water at https://www.mdpi.com/2073-4441/12/8/2253.
“With a large quantity of new date plantings in the region, coupled with increasingly limited water resources in the Colorado River Basin Watershed, the knowledge anticipated to be developed by this research project has the potential to yield large dividends through not only improved water use efficiency, but also best management practices and crop quality,” said Keck of the California Date Commission.
Although the research focused on Coachella Valley dates, Montazar said the results are likely to be useful to growers who have orchards with similar varieties, irrigation practices, and canopy and soil features in other locations.
Montazar's co-authors are Robert Krueger of the USDA-ARS National Clonal Germplasm Repository for Citrus and Dates; Dennis Corwin of USDA-ARS U.S. Salinity Laboratory; Alireza Pourreza UC Cooperative Extension specialist based at UC Davis Department of Biological and Agricultural Engineering; Cayle Little of California Department of Water Resources; Sonia Rios, UC Cooperative Extension advisor in Riverside County; and Richard L. Snyder UC Cooperative Extension specialist emeritus in the UC Davis Department of Land, Air and Water Resources.
The date palm irrigation project was funded by the CDFA Specialty Crop Block Grant Program.
Considered among the most important agricultural innovations in the world, drip irrigation has been researched for decades. UC Cooperative Extension weed management advisor Aliasghar Montazar has taken a close look at its application in organic spinach cultivation, reported Matthew Grassi in Growing Produce.
Not only does drip irrigation use less water than irrigation with sprinklers, the slow emission of water near plant roots also diminishes the crops' susceptibility to disease. Growers believe that ongoing issues with downy mildew is at least partially caused by moisture that sprinklers leave in the plant canopy.
“Being certified organic, there is really nothing they can use as fungicide; so it is a big problem,” Montazar said. “So, we said ‘Let's try drip (irrigation) in spinach.'”
Early results are promising. Montazar has analyzed enough field data from the plots to directly correlate a four- to five-times reduction in downy mildew disease in plots grown with drip irrigation compared to sprinkler-irrigated plots.
“The other thing to note is there is a nice savings on energy as well,” Montazar said. “Another grower reported he saved $200 an acre on energy savings from getting off the sprinklers. Because with drip, there is less pressure needed, so it consumes less energy (to pump water).”
California growers can download a new series of publications summarizing efficient nitrogen management practices from UC Agriculture and Natural Resources. The publications are designed to assist growers in complying with state regulations for tracking and reporting nitrogen fertilizer applied to crops, in an effort to prevent nitrogen from leaching into groundwater.
The science-based publications are associated with a series of trainings for growers and Certified Crop Advisers to develop efficient nitrogen management practices, an effort coordinated by UC ANR's California Institute for Water Resources.
“Our role is to provide farmers, agricultural consultants and policymakers the best science possible for making decisions on managing and protecting California groundwater,” said Doug Parker, director of the water institute.
The free publications, created from training materials, lessons learned from the training sessions and from additional UC research, can be downloaded at http://ucanr.edu/nmgmtpublications.
The following publications are now available for download:
· Principles of Nitrogen Cycling and Management
· Irrigation and Nitrogen Management
· Nitrogen Management for Nut Crops
· Nitrogen Management for Deciduous Fruit and Grapes
· Nitrogen Management for Citrus and Avocado
· Nitrogen Management for Cool-Season Vegetables
· Nitrogen Management for Strawberry Production
· Nitrogen Management for Processing Tomato
· Nitrogen Management for Corn on California Dairies
The publications were authored by Parker of California Institute for Water Resources; Patrick Brown, professor in the UC Davis Department of Plant Sciences; Allan Fulton, UC Cooperative Extension advisor, Tehama County; Tim Hartz, UC Cooperative Extension specialist emeritus, UC Davis Department of Plant Sciences; Dan Munk, UC Cooperative Extension advisor, Fresno County; Daniel Geisseler, UC Cooperative Extension specialist, UC Davis Department of Land, Air & Water Resources; Michael Cahn, UC Cooperative Extension advisor, Monterey, Santa Cruz and San Benito counties; Richard Smith, UC Cooperative Extension advisor, Monterey, Santa Cruz and San Benito counties; Marsha Campbell, UC Cooperative Extension advisor emeritus, Stanislaus County; Sat Darshan Khalsa, UC Davis project scientist; and Saiful Muhammad, UC Davis graduate student.
Developed in 2014, the training program has been offered at 11 different locations around the state, most recently in Fresno. More than 1,000 Certified Crop Advisers have taken the training.
The nitrogen management training curriculum was developed by a group of UC ANR faculty, specialists and advisors. The first day focuses on the nitrogen cycle in crop production systems, nitrogen sources, irrigation and nitrogen management, and nitrogen budgeting. The second morning covers annual and permanent crops and nitrogen planning practices.
For more information on the nitrogen management training materials, visit http://ciwr.ucanr.edu/NitrogenManagement.
The Nitrogen Management Training and Certification Program is a joint effort between the California Department of Food and Agriculture, UC Agriculture and Natural Resources, California Association of Pest Control Advisers' Certified Crop Adviser Program and the Regional Water Boards.
When it comes to watering walnuts, most California growers believe you need to start early to keep trees healthy and productive throughout the long, hot summer. But according to striking results from a long-term experiment in a walnut orchard in Red Bluff, growers can improve crop production if they hold off irrigation until later in the season and directly measure their trees' water needs.
The findings from researchers at the University of California may help farmers optimize water use.
“It's a game-changer,” said walnut grower Hal Crain, who welcomed researchers on to his orchard to test irrigation optimization. “It's clear to me you can improve nut quality and yield by applying water based on what the tree wants and needs, rather than just watering when it's hot outside and the soil is dry. That's a big deal for walnut growers and for the entire agricultural industry.”
Changing the paradigm
Crain is a second-generation farmer whose family has been growing walnuts in Butte and Tehama counties for 55 years. Like most walnut farmers, Crain had always started irrigating in early to mid-May when the days grew warmer and the trees sprouted leaves.
“That's standard practice for probably 90 percent of California's walnut growers,” said Crain, walking amid his trees on a sunny afternoon. “The theory is that when you irrigate early, you preserve the deep moisture in the soil that trees need to survive the heat of summer.”
But that's not how it works, the research shows. Instead, trees that grow in saturated soil early in the season don't develop the deep roots they need to thrive.
“With all the water right there at the surface, the lower roots suffer,” explained Bruce Lampinen, UC Cooperative Extension orchard management specialist with the UC Davis Department of Plant Sciences. “Trees end up with a very shallow root system, which doesn't serve them well as they try to extract moisture from the soil later on.”
Lampinen has long suspected that walnuts were getting too much water in the spring.
“A lot of the symptoms we see like yellowing leaves and various diseases can all be explained by overwatering,” said Lampinen.
So Lampinen did what scientists do: He set up an experiment. Five years ago, with funding from the California Walnut Board and the U.S. Department of Agriculture, he joined forces with Ken Shackel, a plant sciences professor with UC Davis, and Allan Fulton, an irrigation adviser with UC Cooperative Extension. Together, they led a team of scientists testing irrigation on Crain's ranch.
“Hal is an exceptional partner,” Fulton said. “Farmers have a lot to accommodate when they host an experiment like this, with researchers going in and out of the orchard at all hours. He had to work around our people and the timing of our water treatments. He's always eager to experiment with technology and learn new things, and he shares what he learns with other growers. Hal completes the circle.”
Tough nut to crack
When is the best time to irrigate? Researchers say the trees hold the answer. Scientists use pressure chambers, which are air-pressure devices that measure a leaf or small shoot to gauge how hard the plant is working to pull moisture from the soil.
“Just because the soil looks dry doesn't mean the plant is suffering,” said Shackel, who specializes in plant physiology. “Pressure chambers let you ask the tree how it's feeling — sort of like taking a human's blood pressure — which is a much more accurate way to measure a plant's water needs.”
For the last five years, the team has been applying different water treatments to five blocks of trees. One block is getting standard, early irrigation. Crain's orchard managers begin irrigating the other blocks when the trees reach different levels of water stress based on pressure-chamber readings.
The trees that experience moderate stress are doing the best. Their irrigation usually starts in mid-to-late June, several weeks later than when standard watering begins.
“You can tell just by looking at that block that the trees are healthier,” said Crain, standing beneath a canopy of lush, green trees. “And, we're starting to see greater yields and better nut quality.”
Translating the research
The research is helping scientists advise farmers on irrigation.
“My biggest take-away is knowing when to start watering is a really important factor to the health of your trees,” Lampinen says.
Pressure chambers — sometimes called pressure bombs — can cost more than $3,000, and high-tech versions are under development.
“I tell growers a pressure bomb would pay for itself even if you just used it once a year to determine when to start watering,” Lampinen said.
Crain is certainly convinced.
“When you irrigate based on your trees' needs, you optimize water,” Crain says. “I'm not using less water overall, but the water I do use is producing more food. That's good news for everyone.”
This story was originally published in the Fall 2018 issue of Outlook Magazine, the alumni magazine for the UC Davis College of Agricultural and Environmental Sciences.
Connecting 9,000 rural households in Guatemala with improved water management and climate-smart agriculture strategies is the goal of a new project led by a team at UC Davis, to ultimately increase food security and reduce poverty in Guatemala's Western Highlands.
“The opportunity to impact so many farmers' lives on this scale is exciting,” said Beth Mitcham, director of the Horticulture Innovation Lab and a UC Cooperative Extension specialist in the UC Davis Department of Plant Sciences. “We're taking lessons learned from our previous research — in Guatemala, Honduras and Cambodia — and building a team to help more small-scale farmers apply our findings and successfully use these innovative practices.”
The new project is part of the U.S. government's global hunger and food security initiative, Feed the Future. The project represents an additional $3.4 million investment in the UC Davis-led Horticulture Innovation Lab by the U.S. Agency for International Development's mission in Guatemala.
The project's international team also includes representatives from Kansas State University; North Carolina Agricultural and Technical State University; the Centro de Paz Bárbara Ford in Guatemala; Universidad Rafael Landívar in Guatemala; and the Panamerican Agricultural School, Zamorano, in Honduras.
“The learning shared between these three U.S. universities and the universities in Honduras and Guatemala will be enriching for all of the institutions involved,” said Manuel Reyes, research professor at Kansas State University who is part of the team. “I find it satisfying that these academic institutions will be investing intellectually in marginalized groups in Guatemala's Western Highlands — and in turn, learning from them too.”
Helping youth envision a future in agriculture
By partnering with local youth groups and agricultural schools, the team will better prepare students for jobs in commercial agriculture and agricultural extension with knowledge of climate-resilient conservation and water management practices.
“Our local team is training youth as entrepreneurs, to see agriculture as an economic opportunity instead of just back-breaking work,” said Meagan Terry, UC Davis junior specialist who is managing the project in Guatemala for the Horticulture Innovation Lab. “They can envision a future in agriculture, with innovative ways to create value-added products or grow high-value crops for niche markets.”
As rainfall patterns vary with climate change, farmers in this region are expected to face increased competition for water. Practices such as rainwater harvesting, drip irrigation and conservation agriculture will become more necessary for small-scale farmers.
Climate-smart lessons from conservation agriculture, drip irrigation
In previous research, the Horticulture Innovation Lab has found that combining drip irrigation with conservation agriculture practices can successfully grow vegetables on small plots of land, without significant yield reductions. These practices improve soil structure, moisture retention and soil health.
Additionally, women farmers who participated in the Horticulture Innovation Lab studies in Cambodia, Honduras and Guatemala favored using these practices for another important reason: reduced labor in relation to controlling weeds, vegetable bed preparation and manual watering.
“I dream for many women, youth and their families, that their lives will be better off because of 'MasRiego' and the science behind this work,” Reyes said. “As for the research, we are learning how to improve this suite of practices so they can be tailor fitted globally. I am convinced that if this picks up, steep sloping lands can be farmed with the soil quality not being degraded — but even being enriched.”
These lessons, as well as findings from the program's “Advancing Horticulture” report about horticultural sector growth in Central America, lay the foundation for this new project.
Curious about partnering with the Horticulture Innovation Lab? The Horticulture Innovation Lab builds partnerships between agricultural researchers in the United States and researchers in developing countries, to conduct fruit and vegetable research that improves livelihoods in developing countries. The program currently has three research grant opportunities for U.S. researchers: one focused on tomatoes, another on apricots, and a third on integrated crop-livestock systems.