The Natural Lawns with Healthy Soils and More Bees Challenge

ORI Summer Interns Sophia DiPietro, Ken Stephens, and Zeke Cochin talk about the Lawn Challenge at Halls Pond in Brookline, MA

Rob Moir describes a friendly competitions between towns where the one with the greatest percentage of households pledging not to spread quick-release fertlizer on lawns wins.  Fertilizing diminishes the amount of carbon grasses drawdown from the atmosphere because roots stay near the surface, push plants apart exposing soil, “sunspills,” and making plants thirsty.  Much of the fertilizer is washed off the lawn or percolates throught the soil to pollute waterways and groundwater feeding harmful algal blooms and ocean dad zones.

A chemical-free natural lawns may build an inch of soil in a year by pushing out carbohydrates as root exudate.  Liquid carbon feeds fungal mycorrhizae and bacteria, that in turn feed soil life up food chains to rabbits, robins, hawks and owls.  Walking on a lawn stimulates the grass to repair and grow. The grass sends out messages across the wood-wide-web for what it needs from bacteria.  The damaged cells increase photosynthesis.  For a ton of root exudate, grass must pull down nearly eight tons of carbon dioxide because about half will go into manufacturing plant fibers while half is root exudate.

Natural lawns that were not watered in Springfield MA were found to have 36 flower species and 94 species of bees. Residential lawns can, in the best of conditions, build an inch of soil in a year.  A lawn with four inches of soil will swell like a sponge to hold seven inches of rainwater.