A study recently published in the journal Global Change Biology sought to better understand which agricultural conditions are optimal for worms. Dr. Olaf Schmidt and Dr. Maria Briones analyzed 215 studies from over 40 countries that explored the relationship between tilling practices and worm population health.
The meta-analysis showed that disturbing the soil less (i.e. no-till farming, conservation agriculture) resulted in significantly more abundant earthworm populations. For example, no-till farmland saw a 137 percent increase in worm populations and a nearly 200 percent increase in soil biomass. Those areas of land in reduced-till for more than ten years saw the most earthworms return to the soil. In contrast, those field that were heavily plowed lost half of their original worm population.
Researchers observed the affect of tilling on 13 species of worms and found that the largest species were most heavily impacted. These creatures, called anecic earthworms, live deep down in the soil. At night-time they wriggle up a single channel, grab food, such as plant matter or manure, and then slide back down the same permanent burrow.
The researchers write that restoring earthworm populations through practing reduced-till or no-till farming “will ensure the provision of ecosystem functions such as soil structure maintenance and nutrient cycling by “nature’s plow.””
The fall 2014 fellows with the UI’s Climate Narrative Project presented their work Thursday night in the University Capitol Center in Iowa City.
Through various mediums (film, radio, visual arts and creative writing) the fellows shared the research and interviews they have compiled over the past fourth months. The theme was “Semester in the Soil: Regenerative Agriculture, Urban Farms and Food.”
Jeff Biggers – writer-in-residence for the UI Office of Sustainability – worked with the students throughout the semester and introduced each presenter Thursday night. He mentioned the relationship between climate change and soil conservation stating “we have science coming out of our ears yet we’re doing very little.”
Erica Damman – an artist and researcher in the Interdisciplinary PhD program focusing on Environmental Humanities – presented her project which was entitled “Soil Testimonies.” The project included sped up video of Damman creating a large charcoal drawing of a sow bug, a crustacean that lives beneath the soil. While the video played Damman also had an audio track of her conducting a fictional interview with a sow bug as it told her about life underground. The project integrated humor with lines like “everything down here is eating everything else” but also discussed the impacts of soil tilling for agriculture which destroys the homes of bugs, worms, and other parts of the soil ecosystem. Damman and the bug also discussed the effects of soil deep freezes which has been as deep as 15 nightcrawlers (or roughly 50 inches) during recent winters. The Ohio native concluded her presentation by stating that “[We need] to think of soil as our companion species.”
Jenna Ladd – an undergraduate majoring in sociology and minoring in Spanish – presented “Immigrant Seeds and Stories” which examined the availability of garden plots for immigrants in Iowa. She began her presentation by stating that “access to local and healthful food is a right not a privilege.” She then showed a photo slideshow with an audio narrative telling the story of immigrants from Mexico and Africa who came to Iowa as climate refugees because the effects of climate change have hampered their ability to farm and garden in their homelands. She cited data from the American Red Cross which shows that the number of climate refugees in the United States is greater than the number of political refugees. Some of the immigrants lack resources to consume “expensive good food” when coming to Iowa and this has led to an increase in obesity rates for some immigrants.
Jeffrey Ding – an undergraduate triple majoring in political science, economics, and Chinese – presented “Dispatches from the Land” which looked at farmers and the future of agriculture in Iowa. He also weaved some humor into his interactive presentation by reminiscing about the days when Hawkeye football was one of the passions in his life instead of “an exercise in mediocrity tolerance.” However most of the presentation was focused on serious issues facing Iowa farmers. He discussed the UI’s Biomass Fuel Project with specific focus on miscanthus – an Asian perennial tallgrass – which is being grown on plots in Iowa and which he referred to as “the field of the future.” Ding also discussed the importance of soil conservation, citing that farmers should “leave the land better than you got it.” He looked at the future of agriculture in Iowa citing that a quarter of farmland is owned by people over the age of 75 and that with Johnson County being the second-fastest growing county in the state it has created a rift between rural interests and urban development. He concluded his presentation by stating “before regenerative agriculture can save us, we have to save us.”
Sarah Nagengast – an undergraduate majoring in environmental policy and planning with a minor in geography and a certificate in sustainability – presented a video documentary entitled “Recipes in an Age of Climate Change.” She focused on the importance of food availability as well as proper food disposal. Approximately 40 percent of food is wasted and when this food is dumped in conventional landfills as opposed to being composted it creates environmentally-damaging greenhouse gases. Not only do consumers contribute to the high amount of food wasted in the United States but often times farmers and producers will dispose of crops that they feel doesn’t meet their standard for selling.
The Climate Narrative Project was sponsored by the Office of Sustainability and the Office of Outreach and Engagement in the Office of Executive Vice President and Provost.