It was his second day on the job at New Mexico State University, and Dr. David Johnson was handed a project. “It was with the USDA and it was to do something good with dairy manure,” he chuckled and continued, “You can imagine my excitement.”
David C. Johnson, NMSU research scientist and molecular biologist, does research for the Institute of Sustainable Agricultural Research at NMSU. He explains that the problem with dairy manure is its salinity, the salt content. “The person who had the project for a decade before me concluded that the resulting compost from dairy manure was bad for soils, and he was right. The resulting compost salinity was 10 times more than most plants can tolerate.”
However, where there’s a will, there’s a way: “My wife (Hui-Chun Su Johnson) also got a little tired of me coming in with all the dirty clothes, and she said we’re going to do something about it,” he laughed. The pair created the Johnson-Su Bioreactor, an easily home-built static composter using a standard shipping pallet, landscaping fabric, a few plastic pipes, and reinforcing wire mesh making it accessible for nearly any homeowner to make. Very clear instructions and photos are available at https://mesanm.org/sustainable-ag-techniques/ .
The static composting process reduced compost end-product salinity. You can use dairy manure but, it’s easily started with just leaves, and requires no turning, just daily watering for one minute. The compost from Johnson-Su composting bioreactors improves seed germination rates when used to coat seeds, improves soil water infiltration and water retention by helping to increase soil carbon content, and increases plant health, plant growth rates, and crop production.
The results that Dr. Johnson has seen leaves him with firm conviction of its future impact. “We can change the planet with this process,” he said. “Fields that we have applied this compost on are producing more biomass than the most productive ecosystems on the planet.”
The compost is ready after one year, and can be used to inoculate soils; Dr. Johnson says, “think of yeast added to bread.” A seven-year experiment using just a one-time dusting of the compost along with full time cover cropping has benefitted soil fertility and resulted in cotton that started at 24 inches in height now growing to six feet tall, producing five bales of cotton per acre, up from 2.5 bales. “There was no fertilizer used and each year I see an increase in production. We’re using the same amount of water on the land but doubling our crop.”
WANT MORE? Learn how to make and take home a Johnson-Su Bioreactor with Cruces Creatives Makerspace, 205 E. Lohman Avenue, from 10:00 a.m. to noon on Saturday, May 26th. More information and https://crucescreatives.org/event-2902369
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The South Central Solid Waste Authority (SCSWA) supports all sound environmental efforts and manages solid waste and recyclables for residents and businesses throughout Doña Ana County. Contact the SCSWA at (575) 528-3800 or visit www.SCSWA.net.