Dirt is something that comes out of a vacuum. Can you imagine growing plants in that? In England, dirt refers to feces, as in dog poo.
Soil, on the other hand is an accumulation of the decaying bodies of plants and animals – many of them microscopic; of salts, chemicals and minerals; of particles of sand, silt, and clay; of organic matter; and of an amazing number of living organisms such as fungi, worms, insects and more.
The best soil is loaded with humus, that magic component that frees up nutrients so that plants can absorb them. Humus-filled soil holds water better, and also creates a porous medium for air exchange and root growth. It is a rich deep color and smells like heaven to a gardener.
For a plant to thrive, it needs a fertile soil, not dirt. This is not accomplished by adding chemical fertilizers. It is achieved by feeding the soil.
How does one feed a soil? My great aunt would bury a fish head and its inedible parts under her lilac bush. My godmother sprinkled her coffee grounds around her peonies. All their plants bore large beautiful flowers. My friend Laura composts her horse manure, garden trimmings and kitchen scraps, turning the mix often before spreading it throughout her vegetable and flower gardens. Her chickens turn the mixture as well as they look for edible treasures from the garden. Her produce is prolific and tasty.
Cory at The Greenhouse Project tends his worm bins with care applying the resulting castings to nourish the soil and, thereby, the plants. Many gardeners use a mulching mower to chop up grass clippings, which leaves them on the ground to feed the soil for healthy grass.
What they are doing is providing the necessary inputs for the microorganisms. These creatures make up the soil biota that loosen minerals from the soil particles with their special secretions. They then gather up the loose nutrients and store them. They also recycle plant matter that improves soil tilth as well as air and water penetration.
You, as a gardener, can feed your soil by digging compost into it, perhaps that you have made yourself. You can also place organic mulches on top of the soil such as straw, shredded newspaper or grass clippings. You can grow nitrogen-fixing plants as green manure cover crops such as clover, peas, vetch and beans. Or, instead of those plants, grow a cereal green manure crop such as annual rye, buckwheat or barley to loosen and nourish the soil. Check out www.soilfoodweb.com
JoAnne Skelly is associate professor & extension educator emerita for the University of Nevada Cooperative Extension.