The best garden soil is not kept in a static state but is well-prepared and continually maintained. As a rule of (green) thumb the best garden soil has a spongy texture feel and strikes a balance between clay for nutrient-holding abilities, sand for drainage, and organic matter for a slow release of nutrients.
Most gardeners understand that a compost pile is a necessary component to their garden. Compost adds the organic nutrients that change dirt into soil for optimal gardening results. Since compost is such a valuable resource you must use it very carefully. Rather than adding compost after harvesting a crop, try waiting until a few weeks before planting the next crop to ensure that none of the compost nutrients are flushed out during rainy days.
For preventing garden soil compaction over time an extra lightweight growing medium is needed. In this case mix an equal quantity of soil, coarse sand, and compost for a top-shelf homemade garden soil blend. This type of soil mix tends to dry out fast, so make a straw mulch around the plants as the final ingredient to perfect garden soil.
Generally you will get a year or two out of your basic soil, but eventually you will need to add a source of rock phosphorus. Plants with adequate phosphorus show steady vigorous growth and earlier maturity. In addition, rock phosphate is rich in minor elements such as zinc, boron, nickel, and iodine which plants need for optimal growth.