Iron Chlorosis Explains how iron deficiency affects trees and plants, and how to correct it. Ohio State University fact sheet.
Lead Contamination In The Garden Covers causes and effects of elevated lead levels, recommends both health and soil screening procedures, and provides guidelines for gardening in areas with lead contamination.
Improving Soils For Vegetable Gardening Ohio State University fact sheet covers soil basics: types, texture and structure, drainage and moisture, nutrients, pH, and cover crops.
Vermiculite.com One-page site giving suggestions on where to purchase vermiculite in the United States, along with some uses and properties of vermiculite.
Improve Your Garden Soil Covers a wide range of garden soil topics, including soil types, pH, nutrients, testing, composting and fertilizers.
The World of Soil An introduction to soil components, acidity, fertility, and care, as well as an extensive collection of links to other soil resources.
The Schundler Company Collection of articles and resources about the horticultural uses of perlite and vermiculite.
Gardening Information: Soil Collection of articles from Oregon State University on various aspects of soil: use of amendments and cover crops, temperature, acidity, moisture, and testing.
Improving Soil Oregon horticulturalist offers information on soil components, pH, testing methods, and nutrients, and means of improving it by using amendments and improving drainage and aeration.
