Plants rely on proper soil conditions to give them nutrients and minerals, and sometimes the ground is just depleted of these elements. This can be due to several factors, including the plants that have been grown in the past. Some plants add to the quality of the soil, and many plants can actually drain soil of those all important nutrients and minerals.
Enriched soil is Loam soil whereby the nutrient content is improved by adding organic fertilizer. This is usually in the form of manure from cows, pigs, rabbits, bats, chickens, and horses
Compost is also added to the soil. Adding compost will always improve soil quality. It is comprised of decomposed or partially decomposed organic matter that provides nitrogen and potassium tothe soil. Compost also encourages the growth of microrganisms which break down many minerals into a form plants can more easily absorb. The microrganisms and worms also act as natural aerators in the soil which help supply oxygen.