Garden Fertilizers vs. Soil Amendments – What’s the Difference?

 

Fertilizers and soil amendments are totally different things – one is meant to improve your soil, the other is meant to feed your plants. But in some cases, a soil amendment is also a fertilizer that contains very specific nutrients and micronutrients.

Improve your garden with soil amendments like compost before adding fertilizer.

For organic gardeners, the goal always is to improve your soil with amendments to build a rich environment of humus, microorganisms, and micronutrients. This encourages deep root growth, strong, disease-resistant plants, beautiful blooms, and abundant fruits and vegetables. The fertility and viability of the soil is the goal, not the quick fix (and sometimes useless application) of fertilizers to stimulate growth.

A soil amendment is any kind of organic or nonorganic material that improves the condition of your garden soil. The primary purpose is to improve the texture of the soil to make water and air pockets readily available to plant roots. For instance, you can amend clay soils to loosen them and improve drainage or add amendments to sandy soils to retain nutrients and water and provide food for microorganisms. Soil amendments can include animal manures, worm castings, fall leaves, perlite, compost, straw, grass clippings, greensand, gypsum, hay, cover crops, or other materials. Manures, compost, and leaves may also be considered slow-release fertilizers as they contain many or all of the nutrients your plants need, especially in combination.

A soil amendment is defined as any material added to a soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration, and structure. The goal is to provide a better environment for roots. 
Colorado State Extension Service

Chemical or organic fertilizers are concentrated nutrients added to the soil to stimulate plant growth. Chemical fertilizers tend to be very high in concentrations and organic fertilizers are somewhat gentler. Fertilizers are sold in ratios, which are marked on their bags, such as 5-3-2: 5 parts nitrogen, 3 parts phosphorus, 2 parts potassium. But one should be aware that a plant will never take up more of any element than it can use.

Fertilizers alone do not help improve a soil’s structure. If your plants are suffering from a lack of air or water in the root zone, or too much water in poorly draining or compacted soil, all the fertilizer in the world won’t help. In fact, if your soil is compacted, fertilizers may just run off the surface and will never be taken up by your plants’ roots.

Courtesy by:

Best fertilizer in the United States.