Over the years I have written several articles about how livestock can help save the planet. Take cows for example—they help with nutrient cycling, they reduce wildfire danger by eating the undergrowth that fuels fires and the help by converting vegetation that we can’t eat into protein that we can, all while helping sequester carbon in the soil. I love to discuss how grazing and browsing animals can (with good management) have a positive effect on the environment while at the same time providing us with food and fiber. We need to remember though, that it’s not just the critters above ground that can have an impact on food production and the environment—more often than not the bugs, bacteria and other life forms under the soil do even more when it comes to feeding the world and protecting our natural resources.Case in point, a recent study published in the journal Nature Communications showed how earthworms have a huge impact on yields, so much so that each year they may be responsible for an additional 140 million metric tons of crop production across the globe.
In this report, researchers at Colorado State University compiled the results of over 50 studies that looked at what happened to crop yields when earthworms were added to the soil. These research projects ran the gambit of agricultural crops from wheat and rice, to maize, barley, and legumes. They also included a variety of soil types, land treatment practices and levels of fertilizer application so that researchers could weigh the benefits of earthworms against these other factors.
The results of this effort found that earthworms add, on average, an impressive 23.3% increase to aboveground crop biomass. This equals out, world-wide, to roughly 140 million additional tons of yield each year. In crop terms, that tonnage equates to 6.5% of global grain yields and 2.3% of all legume production—That’s a lot of additional food—and it doesn’t take into account the impact worms have on other areas of production like livestock forage.We’ve always known that earthworms do a lot of good–they recycle organic waste into nutrients, improve soil structure, and even boost plants’ immunity to pathogens. What we’re starting to realize though is exactly how much of an impact they and the rest of the sub-soil microbial community of bugs, bacteria and fungi really have on agriculture.I’ve talked before about how reports have shown that undertaking practices that improve the health of the sub-soil microbial community (including worms) can reduce the need for synthetic fertilizer, with some studies showing savings of as much as $50 per acre on fertilizer costs. If the “little livestock” below ground have such a large impact on what we grow above ground, wouldn’t it make sense for us to do all we can to help protect the health of this microbial herd? Are there things we could do on our crop and pasture land that could help maintain and grow the number of all these useful critters?Well, it just so happens that many of the same practices that we want to implement to help address things like soil erosion and water quality are the same things that help protect and improve the community of bugs, bacteria and fungi in our soil. No-till and minimum till, cover crops, crop rotation, and other “climate smart” or “soil health” farming techniques can help improve the health of these useful microbes. By farming in a way that more closely mimics the natural system (remember, unless you’re in a desert, nature never leaves ground bare and never uses a plow) we can help restore the health of our soil and with it the vitality of our sub-soil livestock.As we have said so often—production agriculture and environmental protection really can go hand in hand. If we take care of the worms, (and with them the rest of the microbial community) they really can help save the day.
[Podcast] Earthworms: Unsung Heroes of the Soil,
Soil Health & Earthworms,
Farmer's Earthworm Handbook Shares 19 Tips for Building Up Soils with Earthworms