NatureNet Science Fellow Danny Karp checking on his field experiments in an organic romaine lettuce field. © The Nature Conservancy (Cara Byington)

We regularly report on innovations in agriculture, such as biofeedback and “certified transitional” ingredients, but also on tried-and-true methods like composting, or removing weeds in alternative ways. Cara Byington from The Nature Conservancy’s Cool Green Science blog reports on a recent study on nature and farmers:

A new paper in the Journal of Applied Ecology finds that two farm-based food safety practices – removal of non-crop vegetation in and around fields, and abandonment of composting – actually hurt farmers without making food safer.

“The practices are unnecessary,” said Danny Karp, lead author on the study. “Not only are they ineffective for their intended purpose, they damage growers by decreasing crop yields and pest control.”

Karp conducted this research as a NatureNet Science Fellow with The Nature Conservancy and the University of California at Berkeley. As part of his fellowship, Karp collaborated with senior Conservancy scientist Sasha Gennet and others to determine the efficacy of emerging farming practices for food safety.

Death, Disease and Organic Spinach

The impetus for food safety reform and the intense focus on how farm fields contribute to food safety began in earnest in 2006, after an E. coli outbreak killed three people and sickened hundreds in the United States. Though the source of the outbreak was eventually traced to organic bagged spinach harvested from a field on California’s Central Coast, no one could ever definitively say how the spinach had become infected in the first place.

In the end domestic animals and wildlife each took part of the blame. The result: in efforts to comply with new rules and industry pressure, farmers began fencing their fields, abandoning compost, and removing habitat across the Central Coast.

Unfortunately, there was little scientific basis for these actions and people were forced to make sweeping changes to farms and farming practices on the basis of assumption, supposition, and guess work. Yet, as a paper published last year in the Proceedings of the National Academy of Sciences showed, they were guessing wrong, at least when it came to habitat removal.

That study, also by Karp, Gennet and others, showed that removing habitat from farm fields didn’t make food safer. If anything, removing habitat was associated with a marginal increase in food borne pathogens

The bottomline, Karp said at the time, “is that removing habitat from farm fields does not mitigate pathogen risk and there’s no reason to continue it.”

Nature, Farms & Food Safety: What the Science Says

 This latest study builds on that earlier work and looks at the question of nature’s effect on farms, farmers and food safety from another angle. If removing habitat from farm fields doesn’t improve food safety, are other practices equally as ineffective, or worse, potentially damaging?

To answer those questions, scientists wanted know if: (1) preserving non-crop vegetation (habitat) around farm fields provides a pest-control or yield benefit to growers, and (2) properly treated manure-based compost hurts or helps farmers and food safety.

Research was carried out over two growing seasons at 29 sites on certified organic farms on the Central Coast.

Read the rest of the original article here.