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Posts Tagged: honey bee
Extreme weather accelerates nitrate pollution in groundwater
Extreme weather spurred by climate change, including droughts and heavy rains, may increase the risk of nitrates from fertilizers ending up in groundwater, according to a recent study from researchers at the University of California, Davis. The study found heavy rains after a drought caused nitrates to seep 33 feet under farm fields in as little as 10 days. The study was published in Water Resources Research.
“The conventional wisdom was that it could take several weeks to years for nitrates to move from the crop root zones to reach groundwater,” said corresponding author Isaya Kisekka, a professor in the Departments of Land, Air and Water Resources and Biological and Agricultural Engineering. “We found these extreme events, such as California's atmospheric rivers, are going to move nitrate more quickly.”
In this study, different methods were used to measure how much nitrate, a component of nitrogen fertilizer, was seeping down through the soil in a tomato and cucumber crop near Esparto, California. Scientists conducted their research from 2021 until 2023 when California was experiencing periods of drought followed by atmospheric rivers. They measured nitrate during both the growing seasons and the rainy seasons.
Drought can leave more nitrogen in soil
Previous studies have shown about 40% of nitrogen fertilizer used for vegetables isn't absorbed by the plants but remains in the soil. During droughts, crops don't use nitrogen efficiently, leading to excess nitrogen in the soil. This study found that if a drought is then followed by heavy rainfall, that sudden burst of water causes nitrate to seep in groundwater more quickly. The nitrate concentration in the shallow groundwater exceeded the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter for drinking water.
“In California, we often say we swing between droughts and floods,” said Kisekka. “These extreme events that come with climate change are going to make the risk of these chemicals ending up in our drinking water much more severe.”
Groundwater is the primary source of drinking water for most of California's Central Valley. In some regions, such as the Tulare Lake Basin, nearly one-third of drinking and irrigation wells exceed the EPA's safe nitrate level. High nitrate levels in drinking water can increase health risks, especially for young children. It may also increase the risk of colorectal cancer.
Need for real-time soil nitrate monitoring
Central Valley farmers are required to report to the Regional Water Board how much nitrogen they applied to their field and how much was removed as part of the crop's yield. The study compared different ways of monitoring when nitrate from fertilizers seep into groundwater. Kisekka said the results highlight the need for affordable, real-time soil nitrate monitoring tools to help farmers manage fertilizer use efficiently.
By using conservation practices that limit leftover nitrates in the crop's root zone after harvest, farmers can help reduce nitrate contamination in groundwater.
This study's data will also help improve a model called SWAT, which is used to track nitrate seepage into groundwater across California's Central Valley. This effort is part of the Central Valley Water Board's program to regulate irrigated farmlands.
Other UC Davis authors include Iael Raij Hoffman, Thomas Harter and Helen Dahlke.
The study was supported by the USDA Natural Resource Conservation Service through its Conservation Effects Assessment Project. The national project is designed to assess the effectiveness of conservation practices across different watersheds. The study also had support from the USDA National Institute of Food and Agriculture.
The Bee and the Mantis
So here's this praying mantis, a female Mantis religiosa, tucked beneath a Mexican sunflower, Tithonia rotundifola, in a Vacaville garden. She's as still as a stone, and you know how still stones are. Along comes a honey bee,...
A honey bee forages on a Mexican sunflower, Tithonia rotundifola, as a female praying mantis, Mantis religiosa, perches below. (Photo by Kathy Keatley Garvey)
No Labor Day Holiday for the Honey Bees
Holiday? What holiday? It's Labor Day, but honey bees aren't relaxing. They're out in force collecting nectar, pollen, water and propolis. Ever seen them weighted down with huge pollen loads? They seem to have "Herculean strength," don't you...
A honey bee packing a huge load of orange pollen from zinnias as it heads for another blossom in a Vacaville garden. (Photo by Kathy Keatley Garvey)
A honey bee, its wings a'buzzing, slips through the petals of a zinnia. (Photo by Kathy Keatley Garvey)
All finished here. Next zinnia here I come! (Photo by Kathy Keatley Garvey)
Golden Hour, Golden Bee on Gaillardia
Photographers call the first hour after dawn and the last hour before dusk "The Golden Hour." That's when the sunlight is softer and warmer. It's also called "The Magic Hour." Compare that to high noon, when the sun casts such strong highlights and...
A honey bee foraging on Gaillardia during The Golden Hour in a Vacaville garden. (Photo by Kathy Keatley Garvey)
A Honey of a Bee
Is there a doctor in the house? Is there a doctor in the courtyard? Is there a doctor in the honey bee costume? Yes! That was the scene at the Vacaville Museum Guild's Annual Children's Party, held Thursday morning, Aug. 8 in the museum...
Hear that buzz? The Honey Bee (Dr. George Stock) enters the courtyard. With him are Vacaville Museum Guild members Georganne Gebers (right) of Vacaville, and Sharon Walters of Dixon. (Photo by Kathy Keatley Garvey)
Children expressed excitement as they circled The Honey Bee. In the back is a cutout banner of a California dogface butterfly, the state insect, from the Bohart Museum of Entomology. (Photo by Kathy Keatley Garvey)
Little Eloise Vieira loved The Honey Bee. In back is Vacaville Museum Guild member is bee assistant Sharon Walters. (Photo by Kathy Keatley Garvey)
The Solano County Sheriff's Department, Vacaville Police Department and California Highway Patrol all participated in the Museum Guild's Children's Party. The Honey Bee took time out to pose with several of the officers. From left are CHP Officer Mike Barday, Sheriff Sgt. Rex Hawkins, and CHP Officer Erica Tatum. (Photo by Kathy Keatley Garvey)
The Honey Bee poses with "Queen Bee" Ettamarie Peterson of Petaluma, who displayed her bee observation hive at the event. At right is a costumed McGruff the Crime Dog from the Vacaville Police Department. (Photo by Kathy Keatley Garvey)
The Honey Bee gets acquainted with Stanley, a 20-year-old donkey brought to the party by Tina Currie of the Vaca Valley Grange. (Photo by Kathy Keatley Garvey)
