The Soil Foodweb

-- Dr. Elaine R. Ingham, Associate Research Professor in the Department of Forest Science at Oregon State University and President and Director of Research at Soil Foodweb Inc.
http://www.soilfoodweb.com

"What do we mean, organism-wise, when we talk about soil? Agricultural soil should have 600 million bacteria in a teaspoon. There should be approximately three miles of fungal hyphae in a teaspoon of soil. There should be 10,000 protozoa and 20 to 30 beneficial nematodes in a teaspoon of soil. No root-feeding nematodes. If there are root feeding nematodes, that's an indicator of a sick soil. There should be roughly 200,000 microarthropods in a square meter of soil to a 10-inch depth. All these organisms should be there in a healthy soil.

"If those conditions are present in an agricultural soil, there will be adequate disease suppression so that it is not necessary to apply fungicides, bactericides, or nematicides. There should be 40 to 80% of the root system of the plants colonized by mycorrhizal fungi, which will protect those roots against disease.

"What happens when you apply the most fungicides and pesticides to soil? In every single case where we have looked at foodweb effects of pesticides, there are non-target organism effects, and usually very detrimental effects. The sets of beneficial organisms that suppress disease are reduced. Organisms that cycle nitrogen from plant-not-available forms into plant-available forms are killed. Organisms that retain nitrogen, phosphorus, sulfur, magnesium, calcium, etc. are killed. Organisms that retain nutrients in the soil are killed. Once retention is destroyed, where do those nutrients go? They end up in our drinking water; or end up in our ground water. You and I as taxpayers have to pay in order to clean up that water so we can drink it.

"If you grow the proper number and types of bacteria, fungi, protozoa, nematodes and microarthropods, mycorrhizal fungi in the root systems of the plants, you can do away with pesticides. It's been done. We can reduce significantly the amount of fertilizer that goes into that soil. In experiments that have been done all over the country, all over the world, inorganic fertilizer inputs have been reduced, or are not added at all, without reduction in plant growth."

See complete article:
http://www.safe2use.com/ca-ipm/01-02-05-study.htm

"If garden soil is healthy, there will be high numbers of bacteria and bacterial-feeding organisms, which means the beneficial, disease-suppressive organisms will be present. If the soil has received heavy treatments of pesticides, chemical fertilizers, soil fungicides or fumigants that kill these organisms, the tiny critters die, or the balance between the pathogens and beneficial organisms is upset, allowing the opportunist, disease-causing organisms to become problems. If the soil is healthy for the type of vegetation desired, there should be no reason to use pesticides, or fertilizers."

Full article:
http://www.rain.org/~sals/ingham.html

Trees and Toadstools

Introduction
The Soil Foodweb -- Elaine Ingham

Table of Contents
Preface
1. Introductory
-- What are Toadstools?
-- The Ways of Life of Trees and Toadstools
2. The Fungi of Woodlands
3. The Fungus-roots of Trees
4. Problems and Partnerships

Back to the Small Farms Library Index

---