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Earthworms improve soil conditions through aeration by burrowing in pursuit of food. This constant aeration of the soil results in less evaporation and surface run-off, thereby providing for more efficient use of moisture introduced to the soil.
Each earthworm ingests its weight in organic matter every twenty four hours. Its intricate digestive tract makes it possible for the earthworms to excrete highly nutritious fertilizer known as castings. These castings are the most perfect plant food known to man, and contain: 5 times the available nitrogen, 7 times the available phosphorus, 3 times the exchangeable magnesium, 11 times the available potash, and 11/2 times more calcium than found in six inches of good topsoil. The increases are directly attributable to the organic matter eaten by earthworms. Castings are water soluble and immediately available to plant life. Castings do not heat and will not burn plants regardless of the quantity made available to the plant. The action of earthworms in compost piles will speed up the reduction of organic material to one half the time required by bacterial action alone.