About Soil Amendments

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Soil amendments are materials you add to soil to improve its physical or chemical properties. Unlike  fertilizer, the exact ingredients and chemical composition of soil amendments vary among different sources. You can use soil amendments to improve the permeability and water retention characteristics of your soil.  Amendments can also improve the fertility and alter the acidity of the soil, making it easier for plants to access the nutrients they need.  

Compost is used as an organic amendment to improve physical, chemical, and biological properties of soils. Adding compost will increase the moisture-holding capacity of sandy soils, thereby reducing drought damage to plants. When added to heavy clay soils, compost will improve drainage and aeration, thereby reducing waterlogging damage to plants. Compost increases the ability of the soil to hold and release essential nutrients and promotes the activity of earthworms and soil microorganisms beneficial to plant growth. Other benefits of adding compost include improved seed emergence and water infiltration due to a reduction in soil crusting. 

 Gypsum is calcium sulfate, a naturally occurring mineral. It has been touted as beneficial for breaking up compact soil, especially clay soil. It is useful in changing the soil structure of excessively heavy soils which have been impacted by heavy traffic, flooding, over-cropping, or simply overly weatherized.  One of the main uses of gypsum is to remove excess sodium from the soil and adding calcium.

 Lime is a valuable soil amendment that helps plants and lawns flourish by raising soil pH.  A low soil pH, or acidic soil, is often the underlying problem when it comes to many common soil fertility problems.  

At a neutral pH, exisiting soil nutrients are unlocked, and readily available for plant uptake. Neutral soil pH allows microbes and worms to prosper, organic matter to break down, and soil to truly become the living environment it desires to be. In addition, fertilizer is more effective at a neutral pH. When acidic soil is corrected, plants are greener, stronger, use less water, and are more able to resist diseases. Lime is also an important source of calcium for plants. Just as humans need calcium for healthy teeth and bones, plants need calcium for healthy growth.

The cheapest way to lower the soil pH is to add elemental sulfur to the soil. Soil bacteria change the sulfur to sulfuric acid, lowering the soil pH. Sulfur also acts as a soil conditioner and helps reduce the sodium content of soil.