Researchers share tips on how to keep earthworms working for you.

An acre's worth of earthworms can equal the weight of more than 20 hired men. Earthworms are small but productive, eat for free and work all night long in your no-till fields.

Most importantly, everything they do helps your crop.

Replacing horsepower with worm power, earthworms can loosen up soil more effectively than a tractor pulling a deep ripper. Plus, they never demand an ounce ofdiesel fuel or a spare part.

The tiny earthworm could be your most important ally in the long-term effort to improve soil tilth, fertility and quality with no-till. Understanding how earthworms help you and how you can give them a boost could help the partnership out in your fields really blossom.

Miles Of Tunnels

Earthworms can be divided into two distinct categories, maintains soil scientist Eileen Kladivko of Purdue University:

• Shallow-Dwellers: Redworms, greyworms, fishworms and other small species create shallow, random burrows near the soil surface, burrowing about 3 feet per week.
• Nightcrawlers: They dig vertical burrows that can reach 5 or 6 feet into the soil.

With both types of worms, field populations of as many as half a million worms per acre can create 250 miles of tunnels each week, adds Dennis Linden, an Agricultural Research Service scientist in St. Paul, Minn.

Shallow-dwellers' tunnels create space for air and water in the soil, while nightcrawler burrows improve drainage and water infiltration. Though shallow-dwellers' burrows can fill with water during a rainstorm, they…