"Better Homes and Gardens: Soil, Water & Fertilizers" - "Includes articles on making potting mixes, proper watering techniques, nutrient needs, and mulching."

"Do It Yourself.com: Fertilizer, Compost, and Soil" - "Series of projects, articles, and tips on fertilizing, composting, and nutrient management."

"Soil Testing is an Excellent Investment for Garden Plants and Commercial Crops, HYG-1132-99" - "Ohio State University fact sheet covers the benefits of testing garden soil and provides recommendations for testing frequency, collecting a sample, and submitting to a testing lab."

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."

Improve Your Garden Soil - "Covers a wide range of garden soil topics, including soil types, pH, nutrients, testing, composting and fertilizers."

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."

The Schundler Company - Collection of articles and resources about the horticultural uses of perlite and vermiculite.

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."

Vermiculite.com - "One-page site giving suggestions on where to purchase vermiculite in the United States, along with some uses and properties of vermiculite."