What is garden soil? Simply put, it is the mixture of water, air, mineral salts, dead plant material and live organisms. But the question many people ask is how much of each is needed for a successful garden. The answer is: It depends.
Many factors go into determining the amount of organic matter that should be contained in garden soil. One of them is fertility. Irrigation or over-fertilization has a major impact on the quality of the soil. Another factor affecting the quality of the soil structure is the type of plants that are being grown. Different plants require different amounts of nutrients in order to grow well. Also, the quality of the water that is used to keep the plants growing well can make a huge difference in the quality of the garden soil.
If you’re wondering what is garden soil or potting soil vs topsoil, one thing that needs to be known is that different types of gardening have very different requirements. Some gardeners don’t even use compost in their gardens. Others use compost as a soil amendment, but add more organic matter than others do. And then, there are those who are dedicated to high-quality sustainable agriculture, and use nothing but organic matter, high-lighted crops (no pesticides or herbicides) and completely natural compost and fertilizer systems.
Organic matter content is determined by two primary factors. One is the percentage of green matter, and the other is the amount of nutrient-deficient, brownish soil or clay that is present. A soil analysis, in conjunction with a soil testing report, can determine the percentage of green matter and the percentage of nutrient-deficient, browning soil. Knowing what is garden soil or potting soil vs topsoil can help you determine what kinds of amendments you will need to make your plants and crops thrive.
Soils that are rich in nutrients but that lack good structure tend to form clumps and mats. These clumps block water from penetrating the root zone and oxygen from reaching the plant root zone. If this happens, plant roots rot and die. Inorganic matter, on the other hand, can provide plant nutrition in spite of its poor soil structure. Soils with higher organic content are less likely to form clumps and mats, as there is more room for air to circulate and the water and nutrients to be distributed evenly. So soils that are of higher organic content also tend to have good drainage.
Topsoil, on the other hand, is the top layer of the ground. The term is usually used in association with nutrient-deficient soils. Soils that are of good soil structure are rich in both organic matter (black dirt) and mineral particles. Soils that are of a good soil texture are relatively dark in color-from light to deep reddish browns, and they are relatively moist. The presence of organic matter, iron, and trace elements indicates that the garden soil contains a combination of macro-and micro-nutrients needed for plant growth.
It is important to know what you’re buying when you buy inorganic or composted garden soils, because these soils are usually sterile and are not free of living microorganisms. Many commercial fertilizers, however, use synthetic chemicals that destroy microorganisms and do not replenish the soil’s supply of these vital nutrients. The result is often an over-abundance of soil nutrients, including nitrogen and phosphorus, which plants need for optimal growth. The lack of microorganisms also affects water quality, because some forms of bacteria that exist in soils help to break down and digest organics.
Soil testing kits can be used to determine what is in your garden soil. If you find that what you’re buying is not match your expectations, don’t despair; there are still ways to make the soil you’re currently using better match what you want your plants to grow in. For example, if you want your plants to grow in a deeper shade of green than what is currently available, you can add a little bit of bleach to your potting mix. Or, you may have originally purchased a deep colored potting mix but have since changed your mind and opted for a lighter colored mix, in which case, you can add some fertilizer.