Marin’s soil is a non-renewable resource. It took millions of years for rocks to decay into pieces small enough to host the recipe of minerals and organic matter needed to support life and agriculture. Soil educators say that a handful has more living organisms than there are people on planet Earth. These organisms range from visible creates like earthworms, centipedes and grubs, to microscopic worms, bacteria and fungi. The web of life in soil breaks down organic matter, facilitates the transfer of nutrients into plant materials, fixes nitrogen so it can be taken in by plants, kills pathogens and even acts as a water filter and storage system. When this web of life is in balance, it then helps keep diseases in check and plants healthy, while also retaining water. If out of balance, then bad fungi, bacteria and pests get out of control and water runs through soil without proper absorption.
Marin’s organic farmers use a good portion of their time adding nutrition back into the soil and feed the little organisms through cover crops, compost and soil amendments. Some of the most celebrated pioneers of organic farming practices are in Marin. We are lucky to have these visionaries as the stewards of Marin’s soil. For example, Paradise Valley Produce’s Bolinas soil is fed with farm-created compost, compost teas and custom microbial extract of kelp and fish. Indian Valley Farm and Garden at the College of Marin teaches composting techniques and then uses these same practices to amend their dry, clay soils on their land in Novato. County Line Harvest uses natural amendments in pellet forms instead of composts with manures to feed their fields of leafy greens that grace the border of West Marin and Sonoma Counties.
The United Nations’ Food and Agriculture Organization named 2015 the International Year of Soils and this December 5 will be the third-ever World Soil Day. The UN calls soil our “silent ally.” How do you feed the silent ally in your own yard? A good resource for beginning to understand soil science is a film by Marin’s own Deborah Koons Garcia called Symphony of the Soil.