Posts Tagged: imperial

Drip irrigation in arid regions can cut greenhouse gas emissions, improve air quality

Study at Desert Research and Extension Center highlights agriculture's sustainability role

Under the blistering sun of Southern California's Imperial Valley, it's not surprising that subsurface drip irrigation is more effective and efficient than furrow (or flood) irrigation, a practice in which up to 50% of water is lost to evaporation.

But a recent study also concludes that drip irrigation can dramatically reduce greenhouse gas emissions from soil – which contribute to climate change and unhealthy air quality in the region – without sacrificing yields of forage crops alfalfa and sudangrass.

“It was really exciting to see,” said lead author Holly Andrews, a National Science Foundation postdoctoral fellow at the University of Arizona. “The crop yield was at least maintained and in some cases increased, but the water use and gaseous emissions were especially decreased under drip irrigation.”

Desert REC crucial to collecting data

Andrews and her colleagues gathered data from field studies at University of California Agriculture and Natural Resources' Desert Research and Extension Center, a crucial hub of desert agriculture research for more than 100 years. Studies in that context are increasingly important, as much of California and the Southwest becomes hotter and drier.

“We already have this history of looking at drip irrigation at this site, so our study was trying to build on that,” said Andrews, who lauded Desert REC's facilities and staff.

In their study published in Agriculture, Ecosystems & Environment, researchers found that – in comparison to furrow irrigation – drip irrigation in alfalfa slashed per-yield soil carbon dioxide emissions by 59%, nitrous oxide by 38% and nitric oxide by 20%.

Nitrous oxide is a greenhouse gas with nearly 300 times more warming potential as carbon dioxide, and nitric oxide is a precursor to ozone and major contributor to air pollution.

While drip irrigation only decreased water demand 1% in alfalfa, the practice led to a substantial 49% decrease in irrigation for sudangrass. For more fertilizer-intensive sudangrass, drip irrigation also reduced soil emissions of nitrous oxide by 59% and nitric oxide by 49% – the result of drip irrigation making those fertilizers more efficient.

Water management can help mitigate climate change

Studying alfalfa and sudangrass – forage crops with very different fertilizer requirements – was a strategic choice by the researchers. They are number one and number three on the list of most widely grown crops by acreage in the Imperial Valley (Bermudagrass, another forage crop, is number two).

With so much land dedicated to producing these crops, the adoption of drip irrigation at scale could deliver significant benefits to residents' health and quality of life.

“The thought that saving water can increase yields while lowering the emission of trace gases that affect regional air quality and Earth's climate is quite encouraging,” said Pete Homyak, an assistant professor of environmental sciences at UC Riverside who contributed to the study. “This is especially true for the Imperial Valley, an arid region where water is a limited resource and where residents are exposed to bad air quality.”

Homyak, who is affiliated with UC ANR through UC Riverside's Agricultural Experiment Station, said that this study illustrates how changes in water management can substantially mitigate agricultural impacts on the environment.

The study findings should encourage growers to replace furrow irrigation systems with drip irrigation infrastructure – especially in combination with financial incentives from the state, such as cap-and-trade and carbon credit programs, that can help defray high installation costs.

“It really is worthwhile if you're thinking sustainability and environmental activism in how agriculture can actually support climate change mitigation,” Andrews explained. “These practices might be a way that we can start to change that picture a little bit – and make agriculture more sustainable by tailoring irrigation management to local climate conditions.”

In addition to Andrews and Homyak, the other study authors are Patty Oikawa, California State University, East Bay; Jun Wang, University of Iowa; and Darrel Jenerette, UC Riverside.

New research fills gap on best practices for California carrot production

One doesn't need to be a seasoned farmer to know that growing conditions in Canada are completely different than those found in the low desert of California.

And yet, for many years, studies conducted in Canada were used to generate nitrogen uptake data for the California carrot production system, so growers managed their fields based on their own experiences – and that research conducted thousands of miles to the north.

Carrots had been among the crops grown in California that did not have site-specific data to suggest the best source, rate, timing and placement of nitrogen, in the highly variable cropping seasons and locations throughout the state. That's why new information – based on local research and published in August – is invaluable to farmers in Imperial and Kern counties, where the majority of the carrots in California are grown.

Two years of data from two experimental trials at UC Agriculture and Natural Resource's Desert Research and Extension Center – as well as from 10 commercial fields – produced key recommendations for farmers to make the most of their irrigation and nitrogen applications.

“The point is we developed information in your field, based on your practices, your climate, your production system – and this is what is really happening,” said Ali Montazar, UC Cooperative Extension irrigation and water management advisor for Imperial County. Montazar conducted the study alongside Daniel Geisseler, UCCE nutrient management specialist at UC Davis, and Michael Cahn, UCCE irrigation and water resources advisor for Monterey County.

With reliable data gathered under real-world conditions, Montazar said growers now have solid reference points for when – and at what rate – to irrigate and apply fertilizers in the low desert environment. One of the key findings, for example, was that the carrots' nitrogen uptake is generally low in the first 40 to 50 days, so growers are advised to limit their fertilizer application during that period.

Then, by tailoring those basic guidelines to their own site-specific situation and optimizing their practices, growers can maximize the amount of nitrogen taken up by the carrots – and minimize the amount that is leached out.

“Improving irrigation and nutrient management in the desert production system is what local growers are themselves trying to achieve. With improving efficiency and reducing nutrient leaching, we can improve the quality of water in the Salton Sea,” said Montazar, noting the longstanding challenges of reducing contaminants from irrigated lands to protect its unique ecosystem and wildlife.

While contamination of groundwater is not a critical issue in the desert, the best practices in this study can also help carrot growers in parts of California where nitrogen leaching into groundwater and drinking water supplies is a greater concern.

Montazar is currently leading a team in studying carrot-growing management practices under slightly different conditions in Kern County, with the hopes of publishing findings in late summer 2022.

The Imperial County study, “Spatial Variability of Nitrogen Uptake and Net Removal and Actual Evapotranspiration in the California Desert Carrot Production System,” is published in the journal Agriculture, and can be found at https://doi.org/10.3390/agriculture11080752. Findings and recommendations also appear in Progressive Crop Consultant: https://progressivecrop.com/2021/09/new-knowledge-based-information-developed-to-enhance-water-and-nitrogen-use-efficiency-in-desert-fresh-market-carrots/.

Funding for this study was provided by the California Department of Food and Agriculture's Fertilizer Research and Education Program, as well as the California Fresh Carrots Advisory Board.

Former goat herder’s crop research promotes prosperity for Imperial Valley farmers

Oli Bachie, “person of the globe,” researches new desert crops to spur economic growth

While herding goats along dusty roads as a boy growing up in Oromia, Ethiopia, Oli Bachie began striving to improve his economic position in life. His path to a better life passed through the Philippines and Canada before reaching the United States. Now, carrying the mantle of Ph.D., the UC Cooperative Extension farm advisor is doing research to help California farmers take advantage of new opportunities for economic growth.

More than 400 different crops and animals are commercially produced in California. The wide array of agricultural products keep California farmers competitive in the global market. UC Cooperative Extension research into new crops provides growers with information that can lower the risk of trying something new.

Rhodes grass, giant king grass, quinoa and teff are among the crops Bachie has been studying since he joined UC Agriculture and Natural Resources in 2012.

“Giant king grass and Rhodes grass were brought to my attention by companies who wanted me to test their adaptability, biomass yield and nutrition as livestock feed,” Bachie said. “My findings proved that they indeed adapt and produce high biomass and were nutritionally competent or better than many of the low desert grown grass forage crops.”

Two companies provided Bachie with funding to conduct the research.  “We do research for industries, companies and growers as long as they provide funding and if we believe that the outcome of the research benefits our clientele and the local economy,” he explained. 

Viaspace, a company that grows giant king grass in 11 locations in eight countries on four continents, has relied on Bachie's research for establishing its plantings in the Imperial Valley.

“Oli's research helped us establish basic growing procedures and parameters for Imperial County. It provided the critical information that gave us the confidence to start a larger commercial effort in the desert,” said Haris Basit, vice chairman of Viaspace.

To share information with Imperial Valley growers, Bachie has presented his research results on Rhodes grass varieties at field days and workshops and published in the UCCE Imperial AgBrief newsletter and in the proceedings of the 2019 Western Alfalfa and Forage Crops Symposium. During the COVID-19 pandemic, he has been giving talks via Zoom on Rhodes grass as a new emerging crop, including a zoom workshop organized by the University of Arizona.

“Rhodes grass productivity is well-recognized and is adapted for production not only in the Imperial Valley, but also as far as San Joaquin County and in the state of Arizona,” he said. “A grower in Imperial has started to export Rhodes grass hay to the Middle East. More and more growers within the Imperial Valley and beyond are interested in growing Rhodes grass. I get lots of calls to answer Rhodes grass-related questions. There is now a Rhodes grass seed distributing company in Imperial Valley.”

Giant king grass – a hybrid of elephantgrass and Napier grass, which both grow well as wild plants in Ethiopia – and Rhodes grass are widely grown in Ethiopia. But Bachie didn't study these grasses until he joined UC Cooperative Extension.

Bachie grew up farming with his parents in the rural western part of Oromia, where most coffee and food crops are produced in Ethiopia. “By the way, the name ‘coffee' is derived from a place in Oromia called Kaffaa,” he noted.

“After school in winter, when most farming takes place, I engaged myself in farming,” Bachie said. That afterschool activity piqued his interest in farming and fueled his pursuit of a bachelor's degree in plant sciences from Haromaya University in Ethiopia.

“At that time, when I joined the university, there was only one university in the country,” he said. “I was lucky enough to be one of the few to get university admissions among thousands of high school students.”

In Ethiopia, he worked on a program sponsored by the Ministry of Agriculture and United Nations Food and Agriculture Organization for six years, mostly as a crop protection expert. He studied insects, weeds, pathogens and other crop pests on field crops, vegetables and horticultural crops. 

“The experiences I gathered from Ethiopia help me provide services in Imperial County in multidisciplinary pest management – insects, pathogens, weeds and nematodes – at times when we did not have any pest management advisor in Imperial County,” he said. “It has also given me the opportunity to deal with clientele with easy transfer of scientific knowledge.”

Bachie was selected as an FAO fellow to pursue a master's degree in agronomy at the University of the Philippines. 

“My area of particular concern then was to look at allelopathy (a chemical inhibition of plant extracts or exudates) as a potential inhibition of weed growth,” Bachie said. His plans to develop a biological weed management approach were disrupted when he graduated with a master's degree and he refused to return to his dictator-led home country.

“Ethiopia was then and is still ruled under a brutal government where educated personnel have little value,” he explained. After graduation, he sought settlement in another country. “That supportive state, which I thank dearly, was Canada.”

After earning a master's degree in forestry from the University of Toronto, Bachie accepted a job at a university teaching network administration and came to the U.S., where he earned a Ph.D. in biological sciences at UC Riverside, “Americanizing not only myself, but also my credential and now I serve UC with full interest and strength,” said Bachie, who holds dual U.S. and Canadian citizenship.

In the spring of 2019, Bachie started comparing grass forage crops (bermudagrass, kleingrass, Rhodes grass and teff) with moringa for livestock feed under low desert conditions. Growers will be able to use the research results to decide which crops will be most profitable for their own operations. 

Last summer, Bachie completed a variety trial of quinoa, a grain grown primarily for its edible seeds. He tested the adaptability and grain yield of 35 varieties of quinoa in the heat and biotic stress of the Imperial Valley.

“Of the tested varieties, many tolerated the high heat of the desert and gave promising yields,” said Bachie, who showed the varieties to farmers at an agronomy and irrigation crops field day. “The high grain prices of quinoa in the U.S. and the proof of adaptability and yielding capacity under the low desert condition is expected to attract some growers to grow some quinoa varieties in the Imperial Valley.”

Bachie recently completed a survey of weeds in the county and is planning to publish a handbook titled “Weeds of Imperial County and Management Approaches.”    

“While my journey is a huge zigzag and I came up through difficulties, I am very glad that I was able to travel and survive and made myself from a goat herder to an American Ph.D.,” said Bachie, who has also taught biology and environmental science courses part time at Victor Valley and Imperial Valley community colleges, respectively.

“My travel all over the world has enhanced my concepts of human diversity and the affinity to associate and work with people of various backgrounds. To be sure, I call myself a person of the globe.”

Job Announcement: Imperial Irrigation District PCA - UPDATED WITH LINK

From Al Kalin (akalin@hughes.net), local farmer in Imperial Valley:   The Imperial Irrigation District (IID) searching for applicants qualified and willing to apply to become IID's new PCA. The current PCA is retiring in December so IID is in a hurry to find someone to fill the...

Desert farmers face a new pest threat

Farmers growing vegetables in Southern California and Arizona deserts had to contend with a new pest this fall. The Bagrada bug - a native of East and Southern Africa, Egypt, Zaire and Senegal - made its first appearance in the area, posing especially significant problems to organic farmers, according to an article in Capital Press.

Bagrada bugs were introduced to California last year in Los Angeles and San Diego counties. This past August, farmers began seeing the pest in broccoli, cauliflower, and other cole crops in the Imperial and Coachella valleys, and in southwestern Arizona.

“Bagrada bugs were everywhere; it’s not like we’ve had to look for them,” the story quoted John Palumbo, an extension specialist at the University of Arizona Yuma Agricultural Center.

According to UC Riverside’s Center for Invasive Species Research, adult Bagrada bugs are 5 to 7 millimeters long with black, shield-shaped bodies and distinctive white and orange markings. The adult female is larger than the male.

Bagrada bugs suck sap from young leaves causing small white patches on leaf edges. The damage can prevent the plant from producing edible vegetable heads or can cause double heads that are too small for market. Severe Bagrada feeding can kill the plant.

Capital Press reporter Cary Blake spoke to UC Cooperative Extension Imperial County farm advisor Eric Natwick about the Bagrada bug situation for California desert farmers. Natwick said he saw major Bagrada bug damage in an organically grown red cabbage field in Holtville in late October.

“I’d estimate about 30 percent of the early September-planted transplants developed single heads,” Natwick was quoted. “The other plants (about 70 percent) had no head or two smaller, unmarketable heads.”

Natwick found higher single-head numbers in mid-to-late September-planted cabbage. The field contained adults, nymphs, and eggs.

Female and male Bagrada bugs. (Photo: LA Ag Commissioner's office)

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