Water availability with the continuing drought has become a global issue.
Research shows that one of the easiest ways to nurture the land, help the environment, and have the land retain water is soil conservation through composting — turning food waste and yard scraps into usable garden soil that’s then applied to various landscapes.
Scientists report that increasing organic matter by 1 percent on one acre of land through composting and farming environmentally can save 16,500 gallons of water per acre per year.
Agronomist and U.C. Berkeley Professor of Earth and Planetary Science Stephen Andrews says, “as we increase organic matter of soil (that) 1 percent, we quadruple its water holding capacity!”
Mother Earth’s Fertilizer
Bob Shaffer, an agronomist/soil consultant to vineyards and farms and a farmer himself for 40 years, says he’s found nothing that’s more practical than compost.
Soil contains air, water, and organic matter, he explained. Soil’s components, which include bacteria and fungi, decompose organic matter into humus, a special kind of organic matter.
Humus has a tremendous surface area, said Shaffer. “Like a sponge that soaks up water,” it can hold 16,000 gallons of water for each one percent by weight of humus in the soil.
We think of soil as this inert thing we do stuff to, Andrews said. “It’s a living thing.”
Having organic matter in the soil evens out the soil’s moisture level, which is better for plants, said Andrews. Water keeps the microbial community happy, he said. They need water to survive, as do nutrients, which are water-soluble.
Real-World Application
Water retention through compost is being thoroughly investigated in northern California by John Wick and the Marin Carbon Project, a collaborative project that includes U.C. Berkeley researchers, Marin Conservation Project, the USDA Natural Resources Conservation Service, the Carbon Cycle Institute and Wick’s Nicasio Native Grass Ranch.
The Wicks’ experiment to understand their role as stewards of their ranch quickly developed into discovering how to draw carbon from the air and sequester it into the soil. One important discovery has been the benefit of using compost for moisture retention in soil.
Wick says that in 2008 they applied one half-inch of compost once in a demonstration plot. The plot started holding more water while the control plots in this side-by-side experiment didn’t.
It didn’t matter what the soil type or the vegetation was, said Wick. The system has been holding more and more water every year in a plant-available form, he said.
Compost Uncorked
Geologists of the USGS found that a single application of compost at Alexander Vineyards — 30,000 acres in Sonoma County, California — would save diverting several hundred acres of water a year.
Along with saving water, this has even larger implications — documented increases in native birds and plants, the potential for green grass year-round, and an improved change in the agricultural system.
With the help of UC Berkeley researcher and bio-geochemist Professor Whendee Silver, the Carbon Project has been putting compost on rangeland to improve moisture retention and carbon sequestration. They’re looking at how to apply compost on a large scale using community-produced green waste.
Both Andrews and Wick aren’t daunted by the challenge of applying compost to large tracts of rangeland.
Significance of Soil
“We need to blanket the soil with compost and put the moisture back in,” said Andrews. “We could use helicopters,” he said, “like we put flame retardant on fires. We need out-of-the-box thinking and some creative engineering to do it.”
“We need to recognize the significance of soil,” he said, “especially with drought. This is one thing we all can do a little part and have a huge impact,” he said.
By turning food scraps into compost and applying that to our soil, we’ll improve moisture retention and the sustainability of that soil’s organisms.
And, said Andrews, we won’t have to irrigate or fertilize as much or worry about organisms turning the soil for us. It will be easier to manage our landscape, with less effort on our part.
“Health (and water storage) is enhanced by compost,” said Shaffer. “Ours and the soil’s.”
Feature image courtesy of James Marvin Phelps