Posts Tagged: lettuce

UC nitrate *quick test* protects water quality

Lettuce farmers can use less fertilizer - saving money, cutting back water use and reducing nitrate groundwater contamination risk  - without sacrificing crop yield by employing a "quick test" developed by UC Cooperative Extension, the San Francisco Chronicle reported today.

With the quick test, growers can determine how much nitrogen is in the soil and use only as much fertilizer as their lettuce needs to grow.

UC Cooperative Extension farm advisor Michael Cahn told reporter Julia Scott that he helped one company use 70 pounds less fertilizer per acre and get the same yield.

The Chronicle story was focused on imposing regulations to ease water nitrate contamination in California. Cal State East Bay earth and environmental science professor Jean Moran pointed to agriculture as the primary source of the problem.

"It covers a much larger area, it's a constant input of nitrates in groundwater and you have constant irrigation and over-irrigation, which drives the nitrates deeper into the groundwater," Moran was quoted. "But if you look for new evidence of regulations on nitrate issues in groundwater, you just don't find them."

Lettuce irrigation.

Scientists believe a protein may help keep food safe

Scientists from Cooperative Extension programs at Rutgers University, University of Arizona and University of California worked collaboratively on lettuce field trials that have shown applying a protein to lettuce can reduce the risk of bacterial contamination, according to a story in The Packer. The work also shows that the treatment prolongs the shelf life of processed lettuce used in bagged salads.

The naturally occurring protein the researchers are studying, harpin, triggers a natural defense mechanism in plants, something like the broad spectrum immune response in animals, according to a US Environmental Protection Agency factsheet. While most pesticides act directly on the target pest, harpin causes a protective response in the plant that makes it resistant to a wide range of fungal, bacterial, and viral diseases.

The EPA says, when used properly, harpin has no detrimental environmental effects and its impact on human health is minimal to nonexistent.

The Packer article, written by Dawn Withers, said scientists sprayed harpin on lettuce at different strengths to test areas in California, New Jersey and Arizona five days before harvest. A control area at each site was treated with tap water. They found harpin's greatest effect was longer shelf life when larger doses were applied.

UC studies the use of compost to restore burned areas

Scientists at UC Riverside will apply compost to wildfire-ravaged land after the flames have been doused to determine whether it helps reduce erosion and water pollution and restore vegetation. The project is one of several to be undertaken with funding from the California Integrated Waste Management Board aimed at finding uses for what is expected to be an abundance of compost made from organic waste diverted from landfills, according to a story in the April issue of BioCycle.

The Waste Management Board plans to cut the amount of organic materials now going to landfills by half in the next 10 years. Meeting that goal will require an additional 15 million tons of organic materials to be recycled annually.

The Riverside scientists will quantify the benefits of compost on fire-damaged land by absorbing water, thus reducing surface flow, and by dissipating the energy of rainfall. The study will also attempt to quantify the ability of compost to promote the growth of micro and mesofauna (microbes, worms, insect larvae) in the fire-damaged soil, the BioCycle story says.

Another UC Riverside study funded by the Waste Management Board is focused on using the compost in strawberry, lettuce and tomato production.

Developing crop-specific compost specifications helps farmers avoid using mismatched or poor quality composts, which could result in lower crop yields, according to the article.

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