Good tilth in your soil is a key ingredient. Good soil will form loose crumbly clumps, with a soft fluffy texture when it is wet or dry. When your soil is well aerated it will be easy to till, keep cultivated, and easily allows water, nutrients, and plant roots to penetrate deep into the sub soil. You will see lots of earthworms in healthy soil. Soil deficiencies usually fall into three types of soil.
Silty Soil
Will feel like talcum powder when it is dry and have a slimy feel when wet. Silty soils have a high level of nutrients but they are susceptible to erosion, and compaction because of their fine light texture. Incorporating coarse sand, perlite, and humus along with using cover crops and green manures, you will be able to build up the tilth of your silty soil.
Sandy Soil
Is very gritty and crumbles into fine particles. Because of this the soil drains too quickly and is susceptible to extreme fluctuations of heat and cold during the growing season. Due to their super sharp drainage these soils are unable to retain nutrients. You can improve these soils by combining composted organic materials like grass clippings, leaves, vegetable scraps, coffee grounds, and horse or cow manure.
Clay Soil
Is slick and greasy feeling when wet, hard and brittle when it is dry. Sometimes tinted white, red or yellow these clay soils are rich in minerals but have a low concentration of organic material. Clay soils will hold water well when conditions are dry but tend to get water logged with heavy or several days of rain. You can improve clay soil by adding plenty of compost and vermiculite or perlite. (These are a natural by product of volcanic rock) Use green manures in succession plantings to help build organic matter and till in oat straw or mulch hay to add humus.