The team found that earthworms do not, as was suspected, stimulate carbon sequestration in the soil, which helps to reduce greenhouse gas emissions. Instead, they actually increase greenhouse gas emissions through a variety of ways.
"There was a hypothesis that earthworms were having a positive effect on the greenhouse balance, but they don't," said co-author Johan Six, a plant sciences professor at UC Davis during the study who is now a professor at ETH Zurich in Switzerland. "I would never say you have to take out the earthworms because of greenhouse gases. It's just that you cannot give them credit for reducing greenhouse gases."
The scientific team was led by Jan Willen van Groenigen of Wageningen University in the Netherlands, and, along with UC Davis, included colleagues from Trinity College Dublin, and the International Center for Tropical Agriculture in Cali, Colombia.
The team gathered all relevant published research to date: 57 different experiments.
The research team then employed a statistical technique called meta-analysis to discern overall patterns in the data.
They found that the presence of earthworms increased nitrous oxide emissions from soil by 42 percent and carbon dioxide emissions from soil by 33 percent. But they found no indications that earthworms affect soil organic carbon stocks -- the carbon stored within the soil.
According to the researchers, earthworms likely increase greenhouse gas emissions several ways: they mix organic plant residues in the soil, which may increase decomposition and carbon dioxide emissions; the earthworm gut acts as a microbial incubator, boosting the activity of nitrous oxide-producing microbes; and the earthworms, by burrowing through the soil, make it easier for greenhouse gases in the soil to escape into the atmosphere.
Small changes in soil greenhouse gas dynamics can have important repercussions for global warming, the researchers said. But lead author Ingrid Lubbers from Wageningen University said it is not yet clear to what extent the effects of earthworms on plant growth may negate earthworm-induced increases in greenhouse gas emissions.
"Our literature search also pointed out a large gap in the published studies," Lubbers said. "We need more experiments that include growing plants, as well as more long-term studies and more field studies before we can decide to what extent global worming leads to global warming."
- Author: Jeannette E. Warnert
FoodCorps was formed when President Obama signed legislation in 2009 to engage AmeriCorps in building a more sustainable, healthful and equitable food system in the United States. FoodCorps trains service members to nurture in youth an enduring relationship with healthy food and sends them to underserved areas, where they educate students about gardening and eating garden-fresh produce.
FoodCorps, which served 12 states last year, adds California, Hawaii and New Jersey in 2013. Pending funding, 12 service members will be placed with 10 organizations in California.
“We are thrilled to have been chosen to host a service member,” said Dorothy Smith, UCCE advisor in the Central Sierra office. “Our service member will build interest and participation in the fruit and vegetable gardens we have in Calaveras County schools. A few schools don’t have a garden, and we’ll get those up and running.”
The new FoodCorps service member will work closely with the UCCE CalFresh youth nutrition education program and the UCCE Master Gardener program. Also, Kevin Hesser, the teacher/garden coordinator for Calaveras Unified School District, will collaborate with the service member.
Smith said UC Cooperative Extension and the Calaveras Unified School District decided to apply for the service member when they realized that the goals of the FoodCorps program closely matched their own efforts to enhance youth nutrition by gardening.
“We want people, and especially kids, to eat whole foods, more fruits and vegetables,” Smith said. “We know that when kids plant broccoli, tend it and pick it, they are much more likely to try it. Once people realize a vine-ripened tomato tastes totally different than the ones they buy from the store, they are more likely to grow their own produce and eat it.”
The FoodCorps program also offers a unique experience to the person chosen for the paid position. Service members are often recent college graduates looking to make a difference in the world while gaining work experience before beginning their careers. UC Cooperative Extension will be involved in selecting the candidate for the local program. Applications are due March 24. Apply on the FoodCorps website.
For more information about the FoodCorps program in Calaveras County, contact Dorothy Smith, (209) 754-6476, dorsmith@ucanr.edu.
- Author: Jeannette E. Warnert
Conceived by Michael Cahn, UCCE farm advisor in Monterey County, and programmed by the UC Agriculture and Natural Resources web team, the free website – ucanr.edu/cropmanage – allows farmers to quickly calculate the precise fertilizer and water needs of their crops.
“It’s great,” said Salvador Montes, ranch manager at Corey Ranch in the Salinas Valley, who pilot-tested the software last year on lettuce crops. “It’s very accurate in predicting the irrigation times and fertilizer (needs). It actually worked! We didn’t see any significant yield reduction using less water and fertilizer.”
By applying only the exact amount of water and fertilizer to optimize plant growth, the new website keeps farmers from using too much. Overfertilizing in the past has resulted in groundwater contamination with nitrate, a serious concern in the Salinas Valley and other farming regions. In coastal areas, overpumping wells can lead to sea water intrusion into the aquifer.
“Besides, fertilizer and water are expensive inputs,” Cahn said. “Applying more than the crop needs is like throwing money down the drain.”
On Feb. 26, Cahn will offer a mini CropManage workshop during the 2013 Irrigation and Nutrient Management Meeting at the Monterey County Agricultural Center, 1432 Abbott Street in Salinas. The meeting runs from 7:45 a.m. and concludes with a pizza lunch at 12 noon. Following lunch, the one-hour CropManage workshop begins. No reservations are required.
“Inspiration for this project,” Cahn said, “came from local growers who expressed a need for software to help them use the quick nitrate soil test and weather-based irrigation scheduling in their farming operations.”
Cahn and his colleagues, Tim Hartz, UCCE specialist in the Department of Plant Sciences at UC Davis, and Richard Smith, UCCE advisor in Monterey County, have been conducting trials for years to determine whether the combination of quick nitrogen testing and weather-based irrigation scheduling could reliably reduce the amount of nitrogen that lettuce growers apply.
“We demonstrated a 30-percent reduction in nitrogen fertilizer application,” Cahn said.
The excitement of such a significant result was tempered by the fact that implementing the research results on individual farms would require some serious math.
“When we introduced farmers to the quick nitrate test, some said they would have to hire someone to manage all the data, keep records and make decisions. I realized that we could make this a lot easier for them by programming software to do the work,” he said.
For example, farmers who wish to use weather data to schedule irrigation for lettuce must sign into CIMIS (California Irrigation Management Information Service) to request an email with reference evapo-traspiration for their locations. The data must be punched into an equation along with the irrigation coefficient for lettuce – a figure that represents how much water the lettuce needs – and the size of the lettuce canopy at the time of irrigation. This time-consuming data collection and manipulation is eliminated with CropManage.
“We’ve figured out how to facilitate all these calculations,” Cahn said.
“In effect, they set up a virtual ranch,” Cahn said.
When the farmer is ready to plant, the type of crop and results of a nitrogen quick test are added.
“The program recommends how long and when the irrigation should run and how much nitrogen, if any, should be added,” Cahn said. “The recommendations are updated automatically, taking into consideration the weather and the crop’s stage of growth.”
Throughout the growing season, farmers can monitor the progress of their farms by viewing online tables where irrigation, fertilization and growth are tracked. At any time, all the data can be downloaded as an Excel file the farmer can using for accounting or making reports.
Corey Ranch manager Montes said he accesses CropManage on a tablet computer.
“It’s very easy to use,” Montes said. “It’s easy to log on, input information and read from the tables. I love it. It’s a great tool and is definitely going to help us manage our water and fertilizer in a better way.”
Currently, CropManage contains information for production of romaine lettuce, iceberg lettuce and broccoli. Strawberries and caneberry data will be added to the system. Research is underway on leafy greens, such as spinach and baby leaf lettuce, so they also can be added.
“Everything we learn in research, we will add to CropManage,” Cahn said. “And by using it, growers can give us feedback on how accurate the system is. This is a fluid product. If growers find something that doesn’t work, we can change it.”
All the information uploaded to CropManage is held confidentially and secure on a UC server, protected with a private email address and password. The CropManage website’s privacy policy outlines setup options for users who wish to remain completely anonymous.
Development of the website was supported by a grant from the California Department of Agriculture Fertilizer Research and Education Program.
For more information about the 2013 Irrigation and Nutrient Management Meeting on Feb. 26 or about CropManage, contact Cahn at (831) 759-7377, mdcahn@ucanr.edu.
- Author: Pamela Kan-Rice
The Pistachio Research Board will donate $1.5 million to support a UC Cooperative Extension specialist to conduct nut and fruit disease research. This specialist position, which will be based in the Department of Plant Pathology at UC Davis and housed at Kearney Agricultural Research and Extension Center in Parlier, will help UC ANR fulfill its mission as well as serve the pistachio industry’s needs.
“On behalf of California’s pistachio growers, the California Pistachio Research Board is pleased to invest in the research and extension activities of the University of California and particularly UC Cooperative Extension,” said Bob Klein, manager of the California Pistachio Research Board.
“California farmers, especially pistachio growers, know that research is needed to maintain and improve food production while using our resources wisely and sustainably,” he said. “This position will help address the ever-changing plant disease spectrum in the state, as well as respond to new regulations on both the state and federal levels.”
“The nut and fruit crop pathology specialist was identified as a priority position for UC ANR in our position planning process, and the Pistachio Research Board’s generous gift and foresight enables us to begin recruiting immediately,” Allen-Diaz said. “The board’s six-year commitment gives the position stability. After six years, UC ANR will assume financial responsibility for the position.”
This is the third UC Cooperative Extension academic position funded through a partnership between the agricultural community and UC ANR. The California Rice Research Board and the California Table Grape Commission were the first to partner with the university in this new public-private funding model to fund UC Cooperative Extension positions.
“Hiring outstanding academics to do research and deliver new knowledge is critical to the sustainability of farmers and to the future of California,” said Allen-Diaz. “This new funding model will enable us to act now to work on needed research and deliver science-based solutions.”
“We value our partnership with the UC and will continue to invest in additional research positions as well as support the ongoing research and extension activities of UC scientists,” Klein said.
To discuss potential partnership opportunities to fund academic positions, contact Cindy Barber at Cynthia.Barber@ucop.edu or (510) 987-9139.
- Author: Kathy Keatley Garvey
And it all has to do with butterflies and beer.
Shapiro collected the first cabbage white butterfly of the New Year on both of Obama’s inauguration days, Jan. 20, 2009, and Jan. 21, 2013.
“The constitution mandates the swearing-in for Jan. 20, though it does not require Pieris rapae to emerge on that date,” he quipped.
“Thank you, Mr. President!”
Shapiro, a professor of evolution and ecology who has monitored the butterflies of Central California for more than three decades, sponsors his annual “Beer for a Butterfly” contest to draw attention to the first flight of the cabbage white butterfly (Pieris rapae). Since 1972, he has awarded a pitcher of beer or its equivalent to the first person collecting the first cabbage white of the New Year within the three-county area of Yolo, Sacramento and Solano.
Will Shapiro share his beer with the President? “I'd be delighted to buy Obama a beer, but I suspect he has better things to do with his time!”
Shapiro collected both of his Inauguration Day butterflies along railroad tracks in Yolo County. This year he found the prize-winner in West Sacramento. In 2009, he netted it in Davis.
Of his 2013 find, Shapiro said: “I knew at 9 a.m. on Monday, Jan. 21, that this would be the day - the air just felt different; the sun already felt warm, although the morning low at my place (Davis) had been 32 Fahrenheit at 6:50 a.m. That was the first time in 12 mornings that it hadn't gone below freezing.”
Shapiro arrived at his West Sacramento field site at 11:30 a.m., as the temperature hovered at 59 degrees. By 1:45, the temperature would top out at 66.
Shapiro prowled around the butterfly’s host plants, including wild radish and wild mustard. “Most of the annual Brassicaceae (mustard family), and milk thistle showed frost burn.”
At 1:01 p.m. a male rapae showed up. “It was flying from east to west along the north side of the railroad tracks, just east of the I-80 overpass,” said Shapiro, who was walking along the south tracks. “Unfortunately, at the exact same moment, a fast freight was approaching from the east and I was not about to race it across the tracks! As the train roared by, the butterfly rose straight up and flew over the overpass.”
“I've known all along that the day would come when I would see the first rapae but be unable to catch it,” Shapiro said. “The protocol for such an eventuality is: I count the sight record, but keep the contest open until someone actually catches one and turns it in. I figured this would be the year I'd have to do that. But after the train passed, I milled around looking to see if it would return.”
It did. “At 1:15 it appeared out of nowhere - I think it descended vertically from above - and went directly to where it had been when I first saw it.” He caught it immediately. “It's a male of proper (post-diapause) January phenotype. I waited around until 2 p.m. but saw no more rapae -- just one Red Admiral. So, two species, two individuals for the day.”
Shapiro’s first catch of 2013 was actually on Jan. 1 at the same site, but “it was a slopover from the fall brood.” He declared the contest still under way.
Shapiro, who shares his butterfly monitoring information on his Art's Butterfly World website, holds a doctorate in entomology from Cornell University, and is a fellow of the American Association for the Advancement of Science, the Royal Entomological Society and the California Academy of Sciences. He is also the recipient of UC Davis outstanding teacher and advisor awards.
As for his graduate students, the first to defeat him in his “Beer for a Butterfly” contest was Adam Porter in 1983. Sherri Graves and Rick Van Buskirk followed in the late 1990s.
This year’s competition, however, proved especially satisfying, given that 12 days of freezing temperatures preceded the catch and it occurred again on President Obama’s Inauguration Day.
“Pieris rapae is out, and I can ‘stand down,’ said Shapiro, declaring “It’s now officially spring.”
And as for sharing a beer with President Obama, that offer still stands, too.