Like a symphony, soil is a system of parts existing in magnificent diversity and dynamic relationships. Yet, as is pointed out in the film Symphony of the Soil, “we rarely investigate things as a system.” This October selection for the Salem Progressive Film Series reveals the complexity of soil – its origins and structure and the food web in which it participates. James Cassidy, Senior Instructor of Soil Science at Oregon State University, who will speak following the film, calls soil “the most diverse habitat on earth….a four dimensional complex habitat, more diverse than the oceans.”
That fourth dimension, time, is demonstrated in the film as researchers visit areas of Hawaii that have experienced volcanic eruptions at different times. Recent activity smothered living material leaving inorganic rubble. Gradually organic matter returns and life builds upon life. As time goes by without volcanic disruption, organisms transform the soil and the soil supports increasingly diverse ecosystems.
From rock ground down under glaciers or weathered by wind and water, fine particles carried by wind or water settle over the earth. Over time, micro-organisms turn this dust into living soil. Along with sun and water, these micro-organisms shape the metabolic processes that sustain life. “Life complexes upon itself,“ as the narrator, Dr. Ignacio Chapela of the University of California Berkeley puts it. Cassidy says “a single pinch contains one billion organisms representing ten thousand species.”
Soil is formed at “the interface between biology and geology,” from the interaction of organic and inorganic matter. Terrain, water and climate also play parts in creating a range of soil systems from wetlands to deserts, from permafrost to tropical forest.
Agriculture produces a surplus from the soil, but producing that surplus, consumed by humans and animals, alters soil structure and takes away nutrients. Since the early 20th century “conventional” agriculture responded with increasing use of chemicals – fertilizers, pesticides and herbicides and now crops genetically modified to withstand the chemical assault. Jaspal Singh Chattha, whose father in India diligently applied these methods of the Green Revolution, saw his family’s soil become sicker and wondered if there was another way.
Conventional agriculture wastes water through inefficient irrigation, leaving destructive salts when excess water evaporates. Conventional agriculture also wastes waste, plowing up and clearing out plant residue, leading to erosion from wind and water. According to Cassidy, between salinization, erosion and paving, we lose about 2 acres of productive land every 6-8 seconds. Half a world away from India, in the wheat lands of eastern Washington John Aeschlinn watched spring runoff flood his family’s farm and home each year. He too wanted a better way.
The other, better way, confirmed by farmers who apply it and by IAASTD, a multi-year global assessment of agriculture by a consortium of organizations, is to understand and mimic nature – sowing clover and legumes that make nitrogen available to crops; leaving stubble in the fields to decompose and inhibit erosion; collecting plant residue and manure to make compost. In other words, building soil instead of depleting it.
“Symphony of the Soil”
Salem Progressive Film Series
Guest speakers & audience discussion follow
Thursday October 10 7 pm
Grand Theater 191 High St. NE